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Full text of "Federal motor vehicle safety standards and regulations, with amendments and interpretations"

i^tki 




BOSTOISI 
PUBLIC 
LIBRARY 





SAE J1703b illustrates the approximate pres- 
sure buildup versus the master cylinder piston 
movement with the stroking fixture apparatus.) 
The pressure is relatively low during the first 
part of the stroke and then builds up smoothly 
to the maximum stroking pressure at the end of 
the stroke. The stroke length is about 23 mm 
(0.9 inch). This permits the primary cup to pass 
the compensating hole at a relatively low pres- 
sure. Using stroking fixtures, the WC piston 
travel is about 2.5 ±0.25 mm (0.100 ±0.010 inch) 
when a pressure of 70 kg/sq cm is reached. Ad- 
just the stroking rate to 1,000 ±1,00 strokes per 
hour. Record the fluid level in the master cylin- 
der standpipe. 

S6.13.5 Procedure. Operate the system for 
16,000 ±1,000 cycles at 23±5°C (73.4 ±9°F). Re- 
pair any leakage, readjust the brake shoe clear- 
ances, and add fluid to the master cylinder stand- 
pipe to bring to the level originally recorded, if 
necessary. Start the test again and raise the tem- 
perature of the cabinet within 6 + 2 hours to 
120±5°C (248±9°F). During the test observe 
operation of wheel cylinders for improper func- 
tioning and record the amount of fluid required 
to replenish any loss, at intervals of 24,000 
strokes. Stop the test at the end of 85,000 total 
recorded strokes. These totals shall include the 
number of strokes during operation at 23±5°C 
(73.4 ±9°F) and the number of strokes required 
to bring the system to the operating temperature. 
Allow equipment to cool to room temperature. 
Examine the wheel cylinders for leakage. Stroke 
the assembly an additional 100 strokes, examine 
wheel cylinders for leakage and record volume 
loss of fluid. Within 16 hours after stopping 
the test, remove the master and wheel cylinders 
from the system, retaining the fluid in the cylin- 
ders by immediately capping or plugging the 
ports. Disassemble the cylinders, collecting the 
fluid from the master cylinder and wheel cylin- 
ders in a glass jar. When collecting the stroked 
fluid, remove all residue which has deposited on 
rubber and metal internal parts by rinsing and 
agitating such parts in the stroked fluid and 
using a soft brush to assure that all loose adhering 
sediment is collected. Clean SBR cups in ethanol 
(isopropanol when testing DOT 5 fluids) 



and dry. Inspect the cups for stickiness, scuffing, 
blistering, cracking, chipping, and change in 
shape from original appearance. Within 
1 hour after disassembly, measure the lip and 
base diameters of each cylinder cup by the pro- 
cedures specified in S6. 13.4(a) and (b) with the 
exception that lip or base diameters of cups may 
now differ by more than 0.08 mm (0.003 inch). 
Determine the hardness of each cup according 
to S7.4. Note any sludge or gel present in the 
test fluid. Within 1 hour after draining the 
cylinders, agitate the fluid in a glass jar to 
suspend and uniformly disperse sediment and 
transfer a 100 ml portion of this fluid to a 
centrifuge tube and determine percent sediment 
as described in S7.5. Allow the tube and fluid 
to stand for 24 hours, recentrifuge and record 
any additional sediment recovered. Inspect cyl- 
inder parts, note any gumming or any pitting on 
pistons and cylinder walls. Disregard staining 
or discoloration. Rub any deposits adhering to 
cylinder walls with a clean soft cloth wetted with 
ethanol to determine abrasiveness and remova- 
bility. Clean cylinder parts in ethanol and dry. 
Measure and record diameters of pistons and 
cyhnders according to S6. 13.4(a) and (b). Re- 
peat the test if mechanical failure occurs that 
may effect the evaluation of the brake fluid. 



S6.13.6 Calculation. 

(a) Calculate the changes in diameters of 
cylinders nd pistons (see S5.1.13 (b)). 

(b) Calculate the average decrease in hardness 
of the nine cups tested, as well as the individual 
values (see S 5. 1.1 3(c)). 

(c) Calculate the increases in base diameters 
of the ten cups (see S5. 1.13(e)). 

(d) Calculate the lip diameter interference set 
for each of the ten cups by the following form- 
ula and average the ten values (see S5. 1.13(f)). 

DfDa X 100 = percentage Lip Diameter 
^i'^3 Interference Set 

Where: 

Di = Original lip diameter 

D2 = Final lip diameter 

D3 = Original cylinder bore diameter 



PART 571; S 116-21 



-,,JQSTCW,pUBLIC LIPRARY 



NOV 3 1982 



DEPOSITORY 



S7. Auxiliary test methods and reagent 
standards. 

57.1 Distilled water. Non-referee reagent wa- 
ter as specified in ASTM D1193-70, "Standard 
Specifications for Reagent Water," or water of 
equal purity. 

57.2 Water content of motor vehicle brake 
fluids. Use analytical methods based on ASTM 
D1123-59, "Standard Method of Test for Water 
in Concentrated Engine Antifreezes by the Io- 
dine Reagent Method," for determining the wa- 
ter content of brake fluids, or other methods of 
analysis yielding comparable results. To be 
acceptable for use, such other method must mea- 
sure the weight of water added to samples of 
the SAE RM-1 Compatibility Fluid within ±15 
percent of the water added for additions up to 
0.8 percent by weight, and within ±5 percent 
of the water added for additions greater than 
0.8 percent by weight. The SAE RM-1 Com- 
patibility Fluid used to prepare the samples 
must have an original ERBP of not less than 
182°C (360°F) when tested in accordance with 
S6.1. 

57.3 Ethanol. 95 percent (190 proof) ethyl 
alcohol, USP or ACS, or Formula 3-A Specially 
Denatured Alcohol of the same concentration 
(see Part 212 of Title 26, Code of Federal Reg- 
ulations— U.S. Treasury Department, I.R.S. 
Publication No. 368). For pre-test washings of 
equipment use approximately 90 percent ethyl 
alcohol, obtained by adding 5 parts of distilled 
water to 95 parts of ethanol. 

57.4 IMeasuring the hardness of SBR brake 
cups. Hardness measurements of SBR wheel 
cylinder cups and master cylinder primary cups 
shall be made by using the following apparatus 
and the following procedure. 

S7.4.1 Apparatus. 

(a) Anvil. A rubber anvil having a flat cir- 
cular top 20 ± 1mm (^%6±yi6 inch) in diameter, 
a thickness of at least 9 mm (^/^ inch) and a 
hardness within 5 IRHDs of the SBR test cup. 

(b) Hardness tester. A hardness tester meet- 
ing the requirements for the standard instru- 
ment as described in ASTM D1415-68, "Stand- 
ard Method of Test for International Hardness 
of Vulcanized Natural and Synthetic Rubbers," 
and graduated directly in IRHD units. 



S7.4.2 Procedure. Make hardness measure- 
ments at 23 + 2°C (73.4±3.6°F). Equilibrate 
the tester and anvils at this temperature prior 
to use. Center brake cups lip side down on an 
anvil of appropriate hardness. Following the 
manufacturer's operating instructions for the 
hardness tester, make one measurement at each of 
four points one-fourth inch from the center of 
the cup and spaced 90 degrees apart. Average 
the four values, and round off to the nearest 
IRHD. 

S7.5 Sediment by centrifuging. The amount 
of sediment in the test fluid shall be determined 
by the following procedure. 

S7.5.1 Apparatus. 

(a) Cejitrifuge tube. Cone-shaped centrifuge 
tubes conforming to the dimensions given in 
Figure 6, and made of thoroughly annealed 



r- 36.00 -37.75 mm O.D. 
I7±mm I.D. 




CONICAL TAPER MUST 
BE STRAIGHT 



lOmI / 



<=> 


~ n 


-¥■ 


\ / g 


rO 


\ / £ 


oo 


\ / ° 


1 


\lml/ -H 




\ / S 




\// 1 




A 



FIG. 6 
ASTM 8-in CENTRIFUGE TUBE 



INSIDE SURFACE 
OF CONICAL TIP 



PART 571; S 116-22 



glass. The graduations shall be numbered as 
shown in Figure 6, and shall be clear and dis- 
tinct. Scale-error tolerances and smallest gradua- 
tions between various calibrations made with 
air-free water at 20°C (68°F). 

TABLE V-CALIBRATION TOLERANCES 
FOR 8-inch CENTRIFUGE TUBE 







Volume 


Range, ml 


Subdivision, 


Tolerance, 


to 0.1 


0.05 


+ 0.02 


Above 0.1 to 0.3 


0.05 


±0.03 


Above 0.3 to 0.5 


0.05 


+ 0.05 


Above 0.5 to 1.0 


0.10 


+ 0.05 


Above 1.0 to 2.0 


0.10 


±0.10 


Above 2.0 to 3.0 


0.20 


±0.10 


Above 3.0 to 5.0 


0.5 


+ 0.20 


Above 5.0 to 10.0 


1.0 


+ 0.50 


Above 10. to 25. 


5.0 


±1.00 


Above 25. to 100. 


25. 


+ 1.00 



(b) Centrifuge. A centrifuge capable of whirl- 
ing two or more filled centrifuge tubes at a speed 
which can be controlled to give a relative cen- 
trifugal force (rcf) between 600 and 700 at the 
tip of the tubes. The revolving head, trunnion 
rings, and trunnion cups, including the rubber 
cushion, shall withstand the maximum cen- 
trifugal force capable of being delivered by the 
power source. The trunnion cups and cushions 
shall firmly support the tubes when the centrifuge 
is in motion. Calculate the speed of the ro- 
tating head using this equation: 



rpm = 265 



4 



rcf 



where: rcf = relative centrifugal force, and 
d = diameter of swing, in inches, 
measured between tips of opposite 
tubes when in rotating position. 

Table VI shows the relationship between diam- 
eter, swing, relative centrifugal force (rcf), and 
revolutions per minute. 

S7.5.2 Procedure. Balance the corked cen- 
trifuge tubes with their respective trunnion caps 
in pairs by eight on a scale, according to the 
centrifuge manufacturer's instructions, and place 
them on opposite sides of the centrifuge head. 
Use a dummy assembly when one sample is tested. 



TABLE VI 

ROTATION SPEEDS FOR CENTRIFUGES 

OF VARIOUS DIAMETERS 



Diameter of swing, 
inches ^ 



Rpm at 600 rcf Rpm at 700 rcf 



19 
20 
21 
22 



1490 
1450 
1420 
1390 



1610 
1570 
1530 
1500 



a Measured in inches between tips of opposite tubes 
when in rotating position. 

Then whirl them for 10 minutes, at a rate suf- 
ficient to produce a rcf between 600 and 700 at 
the tips of the whirling tubes. Repeat until the 
volume of sediment in each tube remains con- 
stant for three consecutive readings. 

S7.5.3 Calculation. Read the volume of the 
solid sediment at the bottom of the centrifuge 
tube and report the percent sediment by volume. 
Where replicate determinations are specified, re- 
port the average value. 

S7.6 Standard styrene-butadiene rubber (SBR) 
brake cups. SBR brake cups for testing motor 
vehicle brake fluids shall be manufactured using 
the following formulation: 

FORMULATION OF RUBBER COMPOUND 



Ingredient 


Parts by 




Weight 


SBR type 1503' 


100 


Oil furnace black (NBS 378) 


40 


Zinc oxide (NBS 370) 


5 


Sulfur (NBS 371) 


0.25 


Stearic Acid (NBS 372) 


1 


n-tertiary butyl-2-benzothiazole 




sulfenamide (NBS 384) 


1 


Symmetrical-dibetanaphthyl - p - 




phenylenediamine 


1.5 


Dicumyl peroxide (40 percent on 




precipitated CaCOg)^' 


4.5 



TOTAL 

NOTE: The ingredients labeled (NBS 



153.25 

_) must have 
properties identical with those supplied by the 
National Bureau of Standards 
" Philprene 1503 has been found suitable, 
b Use only within 90 days of manufacture and 
store at temperature below 27°C (SCF). 



PART 571; S 116-23 



Compounding, vulcanization, physical properties, on a flat surface for at least 12 hours at room 
size of the finished cups, and other details shall temperature in order to allow cups to reach their 
be as specified in Appendix B of SAE J1703b. true configuration before measurement. 
The cups shall be used in testing brake fluids S7.7 Isopropanol. ACS or reagent grade, 

either within 6 months from date of manufacture 
when stored at room temperature below 30° 
(86°F) or within 36 months from date of manu- 
facture when stored at temperatures below minus 

15°C ( + 5°F). After removal of cups from re- 36 F.R. 11987 

frigeration they shall be conditioned base down June 24, 1971 



PART 571; S 116-24 



( 



Effective: January 1, 1972 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires — Passenger Cars 
(Docket No. 1-8) 



Proposals to amend § 571.21 of Title 49, "Fed- 
eral Motor Vehicle Safety Standards," to add a 
new standard on retreaded tires for use on pas- 
senger cars, were published October 14, 1967 (32 
F.R. 14280), and March 5, 1970 (35 F.R. 4136). 
Prior to the latter notice, on April 10, 1969, a 
technical conference was held at which a discus- 
sion paper was offered for comments. Based 
upon this prior rulemaking activity, and after 
considering those comments received, a new motor 
vehicle safety standard is hereby issued that re- 
quires manufacturers of retreaded tires for pas- 
senger cars to comply with specified requirements. 

The standard requires retreaded pneumatic 
tires for passenger cars to meet requirements for 
bead unseating, strength, endurance, and high 
speed performance identical to those specified for 
new pneumatic passenger car tires in Motor 
Vehicle Safety Standard No. 109, and to meet 
physical dimension and labeling requirements 
similar to the requirements of Standard No. 109. 
Many comments received in response to the notice 
of proposed rulemaking raised objections to 
these requirements. One objection was that the 
requirements make the retreader responsible for 
the performance of the casing as well as for his 
own retreading process. The casing is, however, 
one of the raw materials used in the retreading 
process. As such, the responsibility for the 
soundness of the casing can lie only with the 
retreader, as it is he who will determine that the 
casing is suitable for retreading purposes. 

Some comments objected to the requirements 
because they believed them to be inappropriate 
for the retreaded tires. Their position was that 
Standard No. 109, in specifying requirements for 
new tires, took into account that new tires are 
designed to be used for more than one tread life. 



Consequently, it is argued, it is unreasonable to 
subject a retreaded tire, whose casing has al- 
ready undergone use through at least one tread 
life, to the same performance criteria as a new 
tire. The purpose of Standard No. 109, however, 
is to provide the public with passenger car tires 
that will perform safely under modern driving 
conditions. These conditions are the same 
whether a new tire or a retreaded tire is involved, 
and call for the same performance requirements, 
as far as is practicable. In agreement with this 
result is the position of certain parties who rec- 
ommended that requirements for new and re- 
treaded tires be identical. Their position was 
that retreaded tires must meet the same minimum 
performance requirements as new tires in order 
to prevent them from being considered as unsafe," 
or as less safe, than new tires. 

Many comments particularly objected to the 
proposed requirement that retreaded tires must 
meet the same physical dimension requirements 
as new tires. It is recognized that tires may 
shrink during the retreading process. A dimen- 
sional requirement for retreaded tires is neces- 
sary, however, to ensure that retreaded tires 
labeled a certain size are within a specified maxi- 
mum tolerance of the size. Consequently, as 
there may be difficulty in requiring retreaded 
tires to meet the same physical dimension re- 
quirements as new tires, the standard as issued 
requires that the section width and the overall 
width of retreaded tires not exceed by more than 
10 percent the figure provided as the section 
width in Appendix A of Standard No. 109. This 
is a slight relaxation of the proposed require- 
ment, which specified a 7-percent tolerance. 

Several objections were also raised to the pro- 
posed requirements for tire casings. These pro- 



PART 571; S 117— PRE 1 



Effective; January I, 1972 



posals were that casings used in retreaded tires 
not have bead wire or cord fabric exposed either 
before or during the retreading process, that they 
not liave a belt or ply removed during retreading, 
and that casings contain the labels on them by 
the original tire manufacturer pursuant to Stand- 
ard No. 109. Many comments objected to the 
prohibition of retreading on casings having ex- 
posed cord fabric either before or during pro- 
cessing. The argument was presented that cord 
fabric exposed during the buffing part of the 
retreading process can be and often is repaired 
without affecting the service life or safety of the 
retreaded tire. As an alternative, some comments 
suggested that this requirement be changed to 
require that cord fabric not be "damaged." Once 
cord fabric has been exposed, however, it is far 
more likely to have been worn, exposed to mois- 
ture, or damaged in some other way. Further- 
more, the suggested language would be nearly 
imix)ssible to enforce, as any determination of 
"damage" would be largely subjective. Requir- 
ing that the fabric not be exposed, however, is a 
far less subjective test, and is consequently less 
subject to error. The proposed requirement has 
accordingly been retained. 

Objections were also raised to the requirement 
that would prohibit the removal of a belt from a 
tire casing during jDrocessing. The argument 
presented was that belt removal, and the addition 
or replacement of a belt as well, should be al- 
lowed if the finished tire can meet the specified 
requirements. The agency has concluded, how- 
ever, that belt removal, addition, and replacement 
raise questions concerning compatibility of ma- 
terials and tire performance for which no data 
is presently available. Until such time as infor- 
mation is available on the effects on tire perfonn- 
ance of belt removal, addition, or replacement, 
these practices will be prohibited in the manu- 
facture of retreaded tires. 

The proposed rule would have required re- 
treaded tires to be labeled with the same informa- 
tion required on new pneumatic tires by Standard 
No. 109. The preamble to the notice indicated 
that this provision, requiring all original labeling 
to be on the casing and to be retained through 
the retreading process, would be accompanied by 



changes in the labeling requirements of Standard 
No. 109 that would require the original label to 
be placed in an area of the new tire sidewall 
where it would not be subject to destruction 
either during use or during retreading. As this 
amendment has not been made to Standard No. 
109, the proposed labeling requirements are being 
modified. They require that each casing be one 
that has been labeled pursuant to S4.3 of Stand- 
ard No. 109, but that the completed retreaded 
tire need only retain enough of the original label 
to display each item of required information in 
at least one location. The labeling requirements 
also provide that the retreaded tire be certified 
by labeling the tire with the symbol DOT, lo- 
cated on the tire as specified in Part 574, "Tire 
Identification and Record Keeping." 

The notice of proposed rule making would 
have required retreaders to submit certain infor- 
mation to the agency, including a statement that 
records would be maintained by the retreader for 
a period of at least 3 years. These record keep- 
ing requirements involved records of materials 
used in the retreading process, records of process 
control, and records of performance tests and 
reported defects and failures. The purpose of 
these proposed requirements would have been to 
provide information to assist retreaders in ascer- 
taining which tires might be suspect in the event 
of a finding of nonconformity or a safety-related 
defect. In consideration of comments received, 
the standard as now issued does not contain 
record keeping requirements, and record keeping 
by retreaders will be on a voluntary basis, con- 
sistently with the other standards. The NHTSA 
strongly recommends, however, that retreaders 
retain information on the materials and processes 
that they use, so that in the event of a defect or 
noncompliance they will be able to determine 
which tires are involved. 

Similarly, the standard does not require re- 
treaders to maintain records of performance tests 
or of reported defects and failures. Retreaders 
should be aware, however, that they are required 
to exercise due care in manufacturing retreaded 
tires to comply with this standard, and that in- 
formation of this type is likely to be an important 
step in proving due care. 



PART 571; S 117— PRE 2 



Effective: January 1, 1972 

Effective date : January 1, 1972. Issued on April 14, 1971. 

In consideration of the foregoing, § 571.21 of Douglas W. Toms, 

Title 49, Code of Federal Regulations, is amended Acting Administrator 
by adding a new motor vehicle safety standard. 

No. 117, "Retreaded Pneumatic Tires: Passenger 36 F.R. 7315 

Cars" as set forth below. April 17, 1971 



PART 571; S 117— PRE 3-4 



Effective: January 1, 1972 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket No. 1-8) 



This notice is issued in response to petitions 
for reconsideration received concerning Motor 
Vehicle Safety Standard No. 117, "Retreated 
Pneumatic Tires," 49 CFR §571.21, published 
April 17, 1971 (36 F.R. 7315). 

Timely petitions were received from 8 parties; 
Bandag Incorporated, National Tire Dealers and 
Retreaders Association (by the firm of Sellers, 
Conner & Cuneo), The Mississippi Independent 
Tire Dealers Association, Alabama Tire Dealers 
and Retreaders Association, and The Louisiana 
Independent Tire Dealers Association, Owens- 
Corning Fiberglas Corp., American Retreaders 
Association, the Goodyear Tire and Rubber Com- 
pany, the Rubber Manufacturers Association, 
and the B.F. Goodrich Tire Company. Certain 
other petitions were received more than thirty 
days after publication of the standard, and while 
they are petitions for rulemaking imder the 
agency's procedural rules (49 CFR § 553.35) 
they have been considered in the issuance of this 
notice. 

1. Availability of casings. Paragraph S5.2.3 
of the standard requires that each retreaded tire 
be manufactured with a casing that has been 
labeled pursuant to S4.3 of Motor Vehicle Safety 
Standard No. 109. In effect, only casings from 
tires manufactured on or after August 1, 1968, 
have been required to have this information 
l)ermanently labeled on the tire. According to 
many petitions, the period between August 1, 
1968 and January 1, 1972, the standard's effective 
date, has been too short to allow the accumula- 
tion of a sufficient supply of casings that bear the 
required labeling. Many petitioners tliorefore 
requested that casings labeled pursuant to Stand- 
ard No. 109 not be required until 1974 or 1975. 
These requests are denied. However, in order to 
make additional casincs available the standard 



has been amended to allow, between January 1, 
1972 and January 1, 1974, the use of some casings 
labeled with specific fractional markings that 
were first introduced in 1965. These casings are 
those for use on wheels having diameters of 14 
or 15 inches, marked with the size designations 
6.45, 6.85, 6.95, 7.35, 7.75, 8.15, 8.25, 8.45, 8.55, 
8.85, 8.90, 9.00, or 915, and labeled with certain 
information as a result of the "Tire Advertising 
and Labeling Guides" which were adopted by 
the Federal Trade Commission on July 5, 1966. 
In situations where these casings are used, the 
retreader is required to label them further, in a 
permanent manner, with a maxinumi load rating 
and maximum permissible inflation pressure ob- 
tained from a table incorporated into the stand- 
ard. Casings that contain the specified informa- 
tion, together with the maximum load rating and 
maximum permissible inflation pressure added 
by retreaders, will be labeled with most of the 
information required on new tires by Standard 
No. 109, and in accordane with Section 201 of 
the National Traffic and Motor Vehicle Safety 
Act (15 U.S.C. 1421). Manufacturers who use 
these older casings should be aware, however, 
that retreaded tires manufactured with them 
must meet the same perormance requirements as 
tires manufactured with casings that have been 
certified tobe in compliance with Standard No. 
109. 

2. Application of the DOT certification mark. 
Paragraph S6 of the standard requires the man- 
ufacturer to certify each retreaded tire by af- 
fixing to the tire the symbol DOT, as provided 
in section 574.5 of the Tire Identification and 
Recordkeeping regulations. The Administration 
takes the position that affixing the DOT before 
the effective date of the standard is inconsistent 
with the intent of the National Traffic and Motor 



PART 571; S 117— PRE 5 



Efftctive: January 1, 1972 



Vehicle Safety Act, as it is only with respect to 
tires manufactured after the effective date that 
certification has legal significance. At the same 
time, under tlie Act all retreaded tires manu- 
factured on or after January 1, 1972, must con- 
tain the DOT mark. Certain petitioners have in- 
dicated that it would be impossible, without a 
substantial disruption of business, for no tire to 
have a permanently affixed DOT symbol on or 
before December 31, 197l', and for all tires manu- 
factured on January 1, 1972, and thereafter to 
have such a symbol. To remedy this problem the 
standard is being amended to allow the use of 
a i)aper label containing prescribed language to 
serve as a valid certification from January 1, 
1972, through February 29, 1972. 

3. Retention of labeling. Certain petitions re- 
quested that paragraph S6.2, which requires cer- 
tain labeling on the casing to be retained, be 
amended because the labeling information some- 
times ajjpears in an area on the tire that is sub- 
ject to buffing. Consequently, it is argued, it is 
imossible to retain the information through the 
retreading process. These requests are denied. 
The required labeling is essential to the appro- 
priate use of the tire and varies from casing to 
casing. It has been determined that the most 
satisfactory way to ensure that correct informa- 
tion of this type appears on the completed tire 
is for the casing manufacturer's labeling to be 
retained. Casings that cannot be retreaded with- 
out destruction of the labeling will consequently 
be unsatisfactory for use. 

4. Casing icitli exposed cord. Many peti- 
tioners objected to the requirements of paragraph 
S5.2.1 that prohibit the retreading of casings 
that have cord fabric e.xposed before or during 
processing. The argument preented is that such 
tires can be retreaded as effectively and will 
l)rovide the same level of performance as tires 
manufactured from casings on which cord fabric 
is not exposed, as long as cords that are exposed 
are not damaged. These requests are denied. 

The NHTSA recognizes that under optimum 
conditions, careful buffing that barely exposes, 
but does not touch, the tire cords can jiroduce 
satisfactory results. In practice, however, tire 
buffing is often not done by precision methods or 
highly trained personnel, especially in the case 



of smaller tire retraders. Any buffing that dam- 
ages or removes part of the tire cords reduces 
thb strength of the carcass at that point. Thus, 
buffing to the cord materially increases the pos- 
sibility of producing unsafe tires. 

Furthermore, exposing tire cords in the re- 
treading process can cause the retreaded tire to 
be unsafe even if the cord is not damaged. In 
the manufacture of new tires, the cords that 
eventually make up the carcass are passed 
through complex adhesive solutions of resin and 
latex, before being dried and coated with rubber. 
Exposed cords in buffed retread carcasses gen- 
erally do not receive comparable treatment to 
bond them to the overlaid rubber. Also, ex- 
posed carcass cords that are not promptly cov- 
ered can absorb moisture from the air, which 
substantially weakens them. 

Since the exposure of belts in belted tires does 
not carry with it the danger of impairment of 
carcass strength as does the exposure of ply 
cords, the standard is amended to make it clear 
that exposure of belt material during processing 
is allowed. Belt material may not, however, as 
specified in S5.2.1, be removed, added, or replaced. 
The petitions in this regard are denied for the 
reasons specified in the preamble to the standard 
published April 17, 1971. 

5. Physical dimension tolerances. Several pe- 
titions noted that although retreaded tires may 
shrink during the retreading process, the physical 
dimension requirements of S5.1.2 allow only for 
a 10% tolerance over the maximum width to 
allow for service growth. An amendment to 
allow some shrinkage was requested. It has been 
determined that a minus 3% deviation from the 
specified section width is justified, and the stand- 
ard is amended accordingly. 

Effective date: January 1, 1972. 

In the light of the above. Federal Motor Ve- 
hicle Safety Standard No. 117 in § 571.21 of Title 
49, Code of Federal Regulations, is hereby 
amended. . . . 

Issued on October 22, 1971. 

Douglas W. Toms 
Administrator 

36 F.R. 20877 
October 30, 1971 



PART 571; S 117— PRE 6 



Effacllv*: January 1, 1972 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket 1-8; Notice 5) 



The purpose of this notice is to amend Motor 
Vehicle Safety Standard No. 117, "Retreaded 
Pneumatic Tires" to increase the number of al- 
lowable casings that may be retreaded, to allow 
ply cord to be exposed in a limited, specified 
manner during the retreading process, and to 
modify the labeling requirements. Motor Ve- 
hicle Safety Standard No. 117 was issued 
April 17, 1971 (36 F.R. 7315), and amended, in 
response to petitions for reconsideration, on 
October 30, 1971 (36 F.R. 20877). Since that 
time certain segments of the industry have re- 
quested additional changes to the standard. This 
amendment is based on those requests. 

1. One major objection that was raised con- 
cerns the prohibition against exposing cord in the 
ply area of the tire during processing. The 
issuance of April 17, 1971, prohibited any tire 
from being retreaded on which cord had been 
exposed either before or during the retreading 
process. The standard was further amended in 
the issuance of October 30, to allow belt material, 
but not ply cords, to be exposed during the re- 
treading process. 

The prohibition against retreading a casing 
that has exposed cord is based primarily on the 
fact that cord that has been exposed may have 
been damaged, thereby weakening the casing and 
increasing the chance that the completed tire will 
be unsafe. This is especially true where cord is 
exposed during the life of the original tire, as 
exposure of cord in this case will generally have 
been caused by excessive wear. However, cord 
has heretofore been exposed during the buffing 
part of many retreading processes, as a method 
of determining whether a sufficient amount of 
old tread rubber has been removed before the 
application of the new tread. The NHTSA 
recognizes the importance of removing a sufficient 



amount of old tread, and that, as stated in the 
October 30 notice, "careful bufiing that barely 
exposes, but does not touch, the tire cords can 
produce satisfactory results." The Administra- 
tion retained the prohibition against bufiing to 
the cord, except for belt material, on the basis 
of the finding that it could result in damage to 
the cord and create unsafe tires. 

After reviewing additional information and 
arguments that have been presented by interested 
parties, the NHTSA has now determined that 
buffing to the ply cord in very limited circum- 
stances can be allowed without incurring the 
risk that cords will be damaged during buffing. 
The amendment issued herewith allows buffing 
during the retreading process only at a splice, 
that is, where two segments of the same ply over- 
lap. Exposure of cord at this point will not 
materially affect casing strength, as there still 
will be one layer of unexposed cord at the splice 
due to the ply overlap. Exposure of ply cord 
at a location other than a splice remains 
prohibited. 

2. The standard as issued April 17, 1971, al- 
lowed only casings that had been labeled pursu- 
ant to Motor Vehicle Safety Standard No. 109 
(49 CFR § 571.109) to be used in the manufacture 
of retreaded tires. The categories of casings that 
could be retreaded under the standard were ex- 
panded in the amendment of October 30, 1971. 
Certain other additions, namely, the inclusion 
of certain 13-inch and 15-inch tire sizes and 
series 70 tires, each of which must contain certain 
labeling, are incorporated by this amendment. 

3. In the preamble to the amendment of 
October 30, 1971, the NHTSA denied requests to 
amend the requirement that the original labeling 
on casings be retained on the completed re- 
treaded tire, and that casings without retainable 



PART 571; S 117— PRE 7 



Effective: Janupry 1, 1972 



labeling; be discarded. Tlie NHTSA's position 
was that retention of tl>e orijiinal labeling was 
the most satisfactory way to ensnre that each 
retreaded tire would be labeled with the appro- 
priate safety information, and it was recognized 
that some casings would have to be rejected be- 
cause of this requirement. Information whicli 
the agency has recently received, however, in- 
dicates that this requirement may reduce the 
number of retreadable casings to a degree not 
anticipated. The shortage of casings will re- 
sult because the labeling on many casings lies in 
an area where it would be removed during the 
retreading process. Although the problem had 
been described in comments at previous stages 
of rulemaking, specific data as to the number 
of available casings was presented to the agency 
after the October 30 amendment. 

The agency has concluded after review of this 
data that to require the discarding of casings 
without retainable labeling could substantially 
impair the industry due to a shortage of casings. 
The NHTSA has accordingly decided to revoke 
these requirements of the standard and to pro- 
pose an alternate labeling scheme. A notice of 
proposed rulemaking to that effect is published 
in this issue of the Federal Register. Much of 
the difficulty e.xperienced by retreaders in finding 
casings that bear labeling not subject to destruc- 
tion results from the fact that many new tires 
carry their required information in locations 
such that it is removed during the retreading 
process. The \HTSA is therefore issuing an 



additional notice of proposed rulemaking which 
v.ould amend Standard No. 109 to require the 
labeling in question to be placed in an area where 
it will not be subject to destruction during the 
retreading process. 

This amendment to Standard No. 117 does not 
change the requirement that only certain casings 
containing original labeling information be used 
in the manufacture of retreaded tires, but 
specifies that, at present, this labeling need not 
be retained on the completed tire. 

In light of the above, section 571.117 of Title 
49, Code of Federal Regidations (Motor Vehicle 
Safety Standard No. 117) is hereby amended. . . . 

Effective date: January 1, 1972. The amend- 
ments issued herein relieve restrictions and im- 
pose no additional burdens on any person. Ac- 
cordingly, it is found, for good cause shown, 
that an effective date less than 180 days, and less 
than 30 days, from the day of issuance is in the 
public interest. 

This notice is issued pursuant to sections 103, 
112, 113. 114, 119, and 201 of the National Traffic 
and Motor Vehicle Safety Act (15 U.S.C. 1392, 
1401, 1402, 1403, 1407, 1421) and the delegation 
of authority at 49 CFR 1.51. 

Issued on December 21, 1971. 

Douglas "W. Toms 
Administrator 

36 F.R. 24814 
December 23, 1971 



PART 571; S 117— PRE 8 



EffecKve: January 1, 1972 
Relttuad: March 23, 1972 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket No. 1-8; Notice 7) 



The purpose of this notice is to reissue, with 
certain amendments, Motor Vehicle Safety 
Standard No. 117, "Retreaded Pneumatic Tires." 
Standard No. 117 was published April 17, 1971 
(36 F.R. 7315). In response to petitions for re- 
consideration, the standard was amended October 
30, 1971 (36 F.R. 20877). As a result of addi- 
tional evidence which was presented to the 
agency regarding the requirements for labeling 
of retreaded tires and other issues, the standard 
was amended again on December 23, 1971 (36 
F.R. 24814). On the same day a notice of pro- 
posed rulemaking was also published proposing 
new labeling requirements (36 F.R. 24825). 
This notice is issued both in response to two 
petitions for reconsideration concerning the 
amendment of December 23, and to incorporate 
amendments based on the notice of proposed 
rulemaking of December 23. 

The issues raised by the two petitions, one 
from the National Tire Dealers and Retreaders 
Association and the other from the Rubber 
Manufacturers Association, concern the avail- 
ability of casings, casing labeling, and the physi- 
cal dimension requirements of the standard. 
Requirements for labeling retreaded tires, which 
are related to the requirements for casing label- 
ing, are dealt with below in the discussion of the 
amendments that are based on the notice of pro- 
posed rulemaking. 

Availdbility of Casings. The petitions re- 
quested that additional casing sizes, namely 5.20, 
6.40, 7.50, 8.00, 8.20, 8.50, 8.85, 9.50, 145, 155, 165, 
175, 185, 195, and 205 be added to the list of 
usable casings. The request that sizes 5.20, 6.40, 
7.50, 8.00, 8.20, 8.50, and 9.50 be added is denied. 
One purpose of Standard No. 117 is to limit 
usable casings to those manufactured within a 
limited period before the effective date of the 



standard. While these sizes were in fact manu- 
factured during the period 1965-1967, unlike 
sizes presently allowed they were also manufac- 
tured in large numbers well before this period. 
It has not been demonstrated that these par- 
ticular casing sizes are needed in order to ensure 
an adequate casing supply, and consequently 
they are not added to the list of usable casings. 
However, the remaining requested casing sizes, 
8.85, 145, 155, 165, 175, 185, 195, and 205 are 
permitted to be used by this amendment as it 
appears that they were not in widespread use 
before the other sizes permitted to be used under 
the standard. In addition, the NHTSA has de- 
termined that some additional sizes, mostly 
radial sizes, may also be retreaded, and the pro- 
posed Table I has been amended accordingly and 
made part of the standard. 

Casing labeling. As amended December 23, 
1971, paragraph S5.2.4 of the standard required 
retreaded tires to be manufactured using casings 
that were either labeled in accordance with S4.3 
of Standard No. 109, or until January 1, 1974, 
of certain enumerated sizes manufactured before 
the effective date of Standard 109. They were 
to be labeled with : ( 1 ) the generic name of the 
cord material used in the plies of the tire, (2) 
the actual number of plies, (3) the size of the 
tire, and (4) whether the tire is tubeless or tube 
type. The petitions have requested that casings 
not be required to contain this information. 

The reason for requiring the casing, whether 
manufactured before or after the effective date 
of Standard 109, to contain the specified infor- 
mation is to provide information that retreaders 
can retain or carry over for the purpose of label- 
ing retreaded tires. The only reliable source for 
much of this information is the casing. 



PART 571 ; S 117— PRE 9 



Effccllvc January 1, 1972 
Rcrssued: March 23, 1972 



The petitions have indicated, however, that 
not all of the information appears on many of 
the pre-Standard No. 109 casings, or appears in 
such a way that it cannot practicably be used 
for purposes of relabeling. Tiie NHTSA has 
accordingly decided to modify the labeling re- 
quirements for pre-Standard No. 109 casings, 
and to make requirements for "DOT" casings 
consistent with them. As amended in this issu- 
ance, casings need only be labeled with (a) the 
tire's size designation, and (b) its actual number 
of plies or ply rating. Information obtained by 
NHTSA has indicated that almost all casing 
sizes allowed to be used by the standard had this 
information permanently labeled onto the tire 
sidewall. 

The standard requires the casing to contain 
its original size marking. It also requires that 
the designated size of the retreaded tire be no 
larger (although it may be smaller) than the 
size of the original casing. Size is the chief 
criterion for consumers in the purchase of tires. 
The NHTSA has concluded that retreaded tires' 
sizes must be related to original casing markings 
in order to provide assurance that the correct 
size is placed on the retreaded tire, and that 
retreaders should not be allowed to determine 
casing size or the size of retreaded tires by any 
other means. Both petitions for reconsideration 
requested that this item of information not be 
required, and in this regard they are denied. 

Casings are also required by this amendment 
to be labeled with either the tire's actual number 
of plies, or its ply rating. This modifies the 
proposed requirement that the "actual number 
of plies" appear. This information is also being 
required by today's amendment to appear on the 
retreaded tire. Ply rating is the basic criterion 
for determining the tire's maximum permissible 
inflation pressure and its maximum load. It is 
required to be on the casing because it cannot be 
determined with assurance except from the 
original tire marking. Some tires manufactured 
before the effective date of Standard No. 109 
were not labeled with the actual number of plies, 
but of those that were not, almost all contained 
the ply rating. Consequently, requiring either 
actual number of plies or ply rating to be on 
casings will not reduce significantly the number 
of otherwise retreadable casings, and insofar as 



the petitions requested complete deletion of this 
requirement, they are denied. 

The standard is amended as requested by the 
petitions to eliminate the requirement that the 
generic name of the cord material, and whether 
the tire is tubeless or tube-type, appear on the 
casing. It appears that industry practice before 
the effective date of Standard No. 109 varied in 
the manner that information of this type was 
labeled on new tires, and that requiring the in- 
formation to be on the casing would unnecessar- 
ily restrict the types of usable casings. 

Mention was made in the petitions of the pos- 
sibility of information appearing on new tires 
being rubbed off in service, making casing label- 
ing requirements difficult to meet. The NHTSA 
is of the opinion that, while this is a possible 
occurrence, complete obliteration of the labeling 
is unlikely. More important, however, is the 
fact that casings where the labeling does not 
appear should not, from a safety standpoint, be 
retreaded. The NHTSA has concluded that 
despite any consequent reduction in the number 
of casings, retreaders should not be left to their 
own devices in determining casing size and ply 
rating on completed tires, but that such infor- 
mation, for the safety of consumers, must be 
based on the casing's original markings. 

Physical dime-mion requirements. The peti- 
tions have asked that the physical dimension 
requirements be amended to allow for a 3 per- 
cent minus deviation from the minimum size 
factor specified for the tire's size designation 
and type. The standard presently allows a plus 
10 percent, and minus 3 percent deviation from 
the maximum section width only. The requests 
are based on the tendency of certain retreaded 
tires to shrink temporarily as a result of the 
retreading process. 

These icquests are denied. Data obtained 
from NHTSA tests indicate that the present 
requirements are being met, and that further 
relief is unnecessary. However, as a result of 
a comment received, paragraph S5.1.2 is being 
rewritten for purposes of clarity. 

Labeling. The notice of proposed rulemaking 
published December 23, 1971 (36 F.R. 24825), 
specified a system by which retreaded tires would 
be required to be labeled with certain safety 



PART 571; S 117— PRE 10 



Effective: January 1, 1972 
Reissued: Marcli 23, 1972 



information. The use of an affixed label would 
be allowed for a li nited period followin<? the 
standard's effective date, but after that period 
the information would be required to be perma- 
nently molded into or onto the tire sidewall. 
The final rule issued today adopts this system, 
with certain modifications in the information to 
be provided, resulting from the amendments to 
paragraph S5.2.4. The information is the same 
for both affixed and molded labeling, and con- 
sists of (a) the tire's size designation, (b) its 
maximum permissible., inflation pressure, (c) its 
maximum load, (d) the actual number of plies, 
ply rating, or both, (e) the words "tubeless" or 
"tube type" as applicable, (f) the words "bias/ 
belted" if the tire is of bias-belted construction, 
and (g) the word "radial" if the tire is of radial 
construction. 

Size, maximum load, and maximum permis- 
sible inflation pressure are required because each 
is necessary for proper selection and use of pas- 
senger car tires. "While the standard requires 
the size to be based on the original casing size, 
the values for maximum load and inflation pres- 
sure may, where necessary, be based on a table 
incorporated into the standard. The values in 
the table are based on the values for the tire's 
size designation and type as they appear in 
Standard No. 109 (§ 571.109), and are determined 
according to the tire's size and ply rating, both 
of which are required to be on the casing. 

The words "bias/belted" and "radial" are re- 
quired, where appropriate, in order to identify 
tires of different types of construction. There 
is presently a large body of opinion, supported 
by NHTSA, that mixing tires of differing con- 
struction types on the same vehicle or same axle 
of a vehicle is not in the best interests of safety. 
In the case of the requirement that the words 
"bias/belted" appear, while not proposed in the 
notice of December 23, the information would 
have been available if the proposed language, 
"actual number of plies in the sidewall and the 
actual number of plies in the tread area, if dif- 
ferent," had been retained. The NHTSA does 
not believe labeling the words "bias/belted"' will 
present significant problems for retreaders as 
most belted tires were manufactured after the 
effective date of Standard No. 109, and are con- 
sequently identified as such. Those that were 



not usually contained some similar identification. 
Moreover, it appears that after proper buffing, 
belted tires exhibit visible differences from pure 
bias construction. 

The word "radial" is also being required, de- 
spite the fact that as proposed it would not have 
been required until permanent markings were 
required. At the time of the proposal, however, 
NHTSA was not aware that radial tires were 
being retreaded. It appears now that they are, 
and in the interests of safety the term "radial" 
is required to be added to all retreaded radial 
tires. 

The words "tubeless" or "tube type" are also 
required to be labeled onto completed retreaded 
tires. Almost all of the comments considered 
this information to be safety related. Even 
though nr.t required to appear on the casing, the 
information will be available to retreaders, as 
( 1 ) most tubeless casings were in fact so marked, 
and (2) a tube-type tire, in most cases, can be 
identified by the lack of inner lining that is 
present on tubeless tires. In those cases where 
identification is not possible, the casing should 
not be retreaded, as this information would like- 
wise be unknown at time of sale. 

The proposed requirement that the tire be 
labeled with the generic name of its cord ma- 
terial is not retained. The comments have 
argued, and NHTSA agrees, that in the case of 
retreaded tires this information is not substan- 
tially related to safety. This, combined with 
the fact that it appears only on certain casings, 
where it must if it is to be relabeled, has con- 
vinced the NHTSA that at present the require- 
ment should not be included in the standard. 

Many comments opposed the requirement that 
labeling be molded into or onto the tire sidewall 
until such a time as new tire labeling was re- 
quired to be placed in a position where it would 
not be buffed off during retreading, and could 
thus be retained through the retreading process. 
These comments argued that permanent labeling 
of this type proposed was unreasonably difficult 
to apply to retreaded tires because tires that 
would require different labeling are retreaded 
in the same matrix. This would require constant, 
time consuming changing of the matrix, and a 
resultant high possibility of error. 



PART 571; S 117— PRE 11 



Effaclive: January 1, 1972 
Reissued: March 23, 1972 

Tires, however, may be subject to many ap- 
plications during their useful life. They are 
transferred from wheel to wheel, and from 
vehicle to vehicle, and each time this takes place 
the information on the tire sidewall becomes 
important. Permanent labeling is therefore re- 
quired if the information is to perform its func- 
tion, as it can be readily assumed that affixed 
labels will last little longer than the first time 
the tire is mounted. Affixed labels, as indicated 
in the preamble to the proposed rule of December 
23, are to be permitted only because methods for 
permanent labeling are not immediately avail- 
able to retreaders, and not as a viable substitute 
for permanent labeling. The NHTSA disagrees 
with industry claims that permanent labeling 
presents unreasonable technical problems. Meth- 
ods for permanent labeling developed for com- 
pliance with the Tire Identification and Record- 
keeping Regulations (49 CFR Part 574) can be 
readily adapted to meet these requirements. In 
fact, of all the information required in today's 
amendment, only the "size" and "maximum load 
rating" will vary to a significant amount from 
casing to casing. Each of the other items of 
required information can be applied uniformly 
to large groups of casings and need not be 
changed from tire to tire if proper sorting is 
done before retreading occurs. 

In light of the above. Motor Vehicle Safety 
Standard No. 117, "Retreaded Pneumatic Tires," 



§571.117 of Title 49, Code of Federal Regula- 
tions, is revised .... 

Effectwe date: The standard's effective date 
of January 1, 1972, has been stayed as a result 
of court litigation, which is still pending. The 
NHTSA does not expect manufacturers to main- 
tain a state of constant preparation so as to be 
able to comply with the standard as of the time 
the stay, should the court so decide, is lifted. 
It has determined, therefore, that additional 
leadtime will be necessary. Accordingly, the 
provisions of the standard, except those regard- 
ing labeling, shall become efl'ective 30 days from 
the day the stay is lifted. The labeling require- 
ments requiring the use of affixed labels shall 
become effective 90 days from that date, and 
those for permanent labeling, approximately one 
year from that date. Notice of exact dates will 
be published in the Federal Register at the time 
the stay is lifted. 

This notice is issued pursuant to the authority 
of sections 103, 112, 113, 114, 119 and 201 of the 
National Traffic and Motor Vehicle Safety Act 
(15 U.S.C. §§1392, 1401, 1403, 1407, 1421); and 
the delegation of authority at 49 CFR 1.51. 

Issued on March 17, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 5950 
March 23, 1972 



PART 571 ; S 117— PRE 12 



GffacHva: June 1, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket 1-8; Notice 9) 



This notice revokes high speed and endurance 
requirements in Motor Vehice Safety Standard 
No. 117, "Ketreaded Pneumatic Tires," in ac- 
cordance with an order of the United States 
Court of Appeals for the Seventh Circuit in 
E & H Tire Company v. Volpe, No. 71-1935, 7th 
Cir., December 5, 1972. It also specifies effective 
dates for provisions of the standard subject to a 
stay that was entered by the court on December 
31, 1971, and removed by its order. 

In a notice published March 23, 1972 (37 F.R. 
9590), the NHTSA indicated that it did not be- 
lieve retreaders should be required to maintain 
a state of constant preparation, so as to be able to 
conform to the standard immediately following 
the lifting of the stay by the reviewing court. The 
NHTSA took this position although the stay 
had been imposed only 24 hours before the stand- 
ard was to become effective, and retreaders should 
have by that time taken all necessary steps to 
achieve -compliance. The notice accordingly spec- 
ified that those requirements of the standard 
dealing with matters other than labeling would 
become effective approximately 30 days after the 
stay imposed by the court had been lifted. Re- 
quirements dealing with affixed labels (S6.3.1) 
were to become effective in 90 days, and require- 
ments for permanent labeling (S6.3.2) in one 
year. 

When these dates were projected, however, the 
NHTSA had assumed a decision would be ren- 
dered by the court in a short time. That assump- 
tion proved incorrect, and the NHTSA has 
determined that more leadtime than that specified 
on March 23, 1972, should be allowed. This 
leadtime will allow retreaders to use up their 
already acquired inventory of casings, and to 
obtain labels to cojiform to the affixed labeling 
requirements. 



This notice provides, therefore, that provisions 
of the standard except those dealing with per- 
manent labeling are effective 120 days from the 
day of publication. The permanent labeling re- 
quirements of the standard are effective one year 
from the day of publication. The NHTSA is of 
the opinion that 120 days is sufficient under the 
circumstances for retreaders to take whatever 
remaining steps are necessary to achieve con- 
formity with these requirements. 

In light of the above. Motor Vehicle Safety 
Standard No. 117, "Retreaded Pneumatic Tires", 
49 CFR 571.117, is amended. . . . 

E-ffective date: June 1, 1973, except for the 
provisions of paragraph S6.3.2, which are effec- 
tive on February 1, 1974. The requirements of 
this standard were originally issued April 17, 
1971, to become effective January 1, 1972. The 
standard in its present form was published 
March 23, 1972, but did not take effect due to a 
stay imposed on December 31, 1971. Accord- 
ingly, adequate lead time has already been pro- 
vided for any long-range steps necessary for 
compliance. The public was notified of expected 
effective dates by the notice of March 23, 1972. 

It is therefore found, for good cause shown, 
that an effective date less than 180 df:ys from the 
date of publication of this notice is in the public 
interest. 

(Sec. 103, 112, 113, 114, 119, 201, Pub. L. 
89-563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421; delegation of authority at 49 
CFR 1.51) 

Issued on January 24, 1973. 

Douglas W. Toms 
Administrator 

38 F.R. 2982 
January 31, 1973 



PART 571; S 117— PRE 13-14 



Effactiv*: Fabruaiy 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 

(Docket No. 71-23; Notice 3) 
(Docket No. 1-8; Notice 10) 



This notice amends Motor Vehicle Safety 
Standards Nos. 109 and 117 (49 CFR 571.109) 
to reduce the minimum size of permanent safety 
labeling to 0.078 inches. Motor Vehicle Safety 
Standard No. 109, "New Pneumatic Tires," was 
amended November 4, 1972 (37 F.R. 23536), to 
specify both a location on the tire sidewall for 
safety labeling and a labeling size of not less 
than %2 of an inch. Motor Vehicle Safety 
Standard No. 117, "Retreaded Pneumatic Tires", 
was amended March 23, 1972 (37 F.R. 9590), to 
specify permanent labeling of the same minimum 
size. 

The Michelin Tire Company has protested 
that the %2 ii^ch minimum size is inconsistent 
with the existing practice of European tire 
manufacturers of labeling tires in letters having 
a size of 0.078 inches (2mm). It has pointed 
out that as a consequence of the amendment, 
European tire manufacturers will have to in- 
crease the size of all existing labeling. The 
NHTSA has concluded that the difference be- 
tween letters 0.078 inches in size and those of 
0.093 inches is not significant, and does not jus- 
tify the resultant expense to manufacturers of 
modifying tire molds. By this notice the 
NHTSA therefore reduces the minimum size to 
0.078 inches for labeling required by S4.3 of 
Standard No. 109. 



Because the permanent labeling provisions of 
Standard No. 117 are intended to be ultimately 
met with new tire labeling, the size requirements 
for permanent labeling in that standard are also 
modified. 

In light of the above, Motor Vehicle Safety 
Standard No. 109, 49 CFR 571.109, and Motor 
Vehicle Safety Standard No. 117, 49 CFR 
571.117, are amended .... 

Effective dates: July 1, 1973, for the amend- 
ment to S4.3 of 49 CFR 571.309; February 1, 
1974, for the amendment to S6.3.2 of 49 CFR 
571.117. These amendments relieve an unneces- 
sary restriction without a significant effect on 
motor vehicle safety. Consequently, it is found 
for good cause that notice and public procedure 
thereon are imnecessary, and that an effective 
date less than 180 days from the day of issuance 
is in the public interest. 

(Sees. 103, 112, 113, 114, 119, 201, Pub. L. 
89-563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421; delegations of authority at 49 
CFR 1.51.) 

Issued on March 8, 1973. 

James E. Wilson 
Acting Administrator 

38 F.R. 6999 
March 15, 1973 



PART 571 ; S 117— PRE 15-16 



I 



EffKtIv*: Jun* 1, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket No. 1-8; Notice 11) 



This notice amends paragraph S6.2 of Standard 
No. 117, Retreaded Pneumatic Tires (49 CFR 
571.117), to allow the temporary certification 
label permitted by that paragraph to be aflixed 
to the sidewall of the tire, as well as to the 
tread. Federal Motor Vehicle Safety Standard 
No. 117 was published March 23, 1972 (37 F.R. 
5950) and amended January 31, 1973 (38 F.R. 
2982). Although the standard relating to the 
placement of a conformity label stated that the 
temporary label would be affixed "to the tread 
of the tire," the NHTSA did not intend to be 
restrictive of the label's location, and the limiting 
language was inadvertent. 

Effective date : Jime 1, 1973. This amendment 
is corrective in nature and imposes no additional 



burden on any person. Accordingly, it is found 
that notice and public procedure thereon are un- 
necessary, and that good cause exists for an effec- 
tive date less than 180 days from the day of 
publication. 

(Sees. 103, 112, 113, 114, 119, 201, Pub. L. 
89-563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421 ; delegation of authority at 49 
CFR 1.81) 



Issued on April 12, 1973. 



James E. Wilson 
Acting Administrator 

38 F.R. 9668 
April 19, 1973 



PART 571; S 117— PRE 17-18 



# 



EffxMv*: January 9, 1974 
F*biuary I, 1974 



PREAMBLE TO AMENDMfNT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 



Pneumatic Tires 
(DMk«t H9. 1-8; Notice 14) 



On August 21, 1973 (38 F.R. 22493), the 
NHTSA proposed to amend 49 CFR §571.117 
(Motor Vehicle Safety Standard No. 117, "Re- 
treaded Pneumatic Tires") to revise retreaded 
tire physical dimension requirements, to facili- 
tate the labeling of bias/belted tires, to specify 
acceptable methods of permanent labeling, and 
to reduce labeling size. Interested persons were 
given the opportunity to submit comments by 
September 24, 1973. Only three comments were 
submitted within the comment period, none of 
which objected to the substance of the proposed 
amendments. Accordingly, the proposed revi- 
sion of paragraphs S5.1.2, S6.3.1, and S6.3.2 of 
49 CFR § 571.117 is adopted without change as 
set forth below. 

Effective date: The amendments to S5.1.2 and 
S6.3.1 are effective January 9, 1974. The amend- 



ment to S6.3.2 is effective February 1, 1974. 
These amendments facilitate compliance with 
the standard, relieve restrictions, and do not re- 
duce the level of safety established by the stand- 
ard. Accordingly, good cause exists and is 
hereby found for an effective date less than 30 
days from publication. 

(Sees. 103, 112, 113, 114, 119, 201 Pub. L. 
89-563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421; delegations of authority at 49 
CFR 1.51.) 

Issued on January 3, 1974. 

James B. Gregory 
Administrator 

39 F.R. 1443 
January 9, 1974 



PART 571 ; S 117— PRE 19-20 



ElhcHv*: February 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 



Retreaded Pneumatic Tires 

(Dockef No. 1-8; Notice 15) 



This notice and an accompanying notice of 
proposed rulemaking (39 F.R. 3571) are intended 
to implement the decision of the United States 
Court of Appeals for the District of Columbia 
in the National Tire Dealers' and Retreaders' 
Association, Inc., v. Brinega?' (Case No. 72-1753; 
decided January 8, 1974). Standard No. 117 
was published in its present form on March 23, 

1972 (37 F.R. 5950) and amended January 31, 

1973 (38 F.R. 2982), March 15, 1973 (38 F.R. 
6999), April 19, 1973 (38 F.R. 9668), May 3, 
1973 (38 F.R. 10940), and January 9, 1974 (39 
F.R. 1443). 

Standard No. 117 would have required, effec- 
tive February 1, 1974, that each retreaded tire 
be permanently labeled with each of the follow- 
ing items of information : the tire's size designa- 
tion; the tire's maximum permissible inflation 
pressure, either as it appears on the casing or as 
set forth in Table 1 of the standard; the tire's 
maximum load, either as it appears on the casing 
or as set forth in Table 1 ; the actual number of 
plies, ply rating, or both; the word "tubeless", 
if the tire is a tubeless tire, or the words "tube- 
type" if the tire is a tube-type tire; the words 
"bias-belted", or the actual number of plies in 
the sidewall and the actual number of plies in 
the tread area, if the tire is of bias/belted con- 
struction ; and the word "radial" if the tire is of 
radial construction. The Court's opinion vacates 
those parts of the permanent labeling require- 
ments dealing with tire size, maximum inflation 
pressure, ply rating, tubeless or tube-type, and 
bias/belted and radial construction. It states 
that the standard should contain requirements 
for permanent labeling of the maximum permis- 
sible load, the actual number of plies, and the 
composition of the material used in the ply of 



the tire. This notice clarifies Standard No. 117 
to require the maximum load to be permanently 
labeled onto each retreaded tire. As that re- 
quirement remains unchanged as a result of the 
Court's ruling, its effective date of February 1, 
1974, is retained. Requirements for permanent 
labeling of the actual number of plies and the 
generic name of the cord material are not pres- 
ently contained in the standard, and are accord- 
ingly proposed in a companion notice published 
on page 3571 of this issue of the Federal Register. 
Under the language of Standard No. 117, the 
deletion of permanent labeling requirements re- 
sults in a continuation of the existing require- 
ment for affixed labeling in paragraph S6.3.1 
with respect to the items of information deleted. 
Any information required to be labeled by para- 
graph S6.3.1 that is not permanently labeled onto 
the tire sidewall, i.e., either retained from the 
casing or relabeled on to the retreaded tire, must 
be included on a label, not easily removable, 
affixed to the tire sidewall. 

In light of the above, paragraph 86.3.2 of 49 
CFR 571.117 (Motor Vehicle Safety Standard 
No. 117) is revised. . . . 

Effective date : February 1, 1974. This notice 
merely restates an effective date established Jan- 
uary 31, 1973 (38 F.R. 2982). 

(Sec. 103, 112, 113, 114, 119, Pub. L. 89-563, 
80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 1403, 
1407, 1421; delegation of authority at 49 CFR 
1.51.) 
Issued on January 24, 1974. 

James B. Gregory 
Administrator 

39 F.R. 3553 
January 28, 1974 



PART 571 ; S 117— PRE 21-22 



i 



EfFecfive: Moy 12, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 117 

Retreaded Pneumatic Tires 
(Docket No. 1-8; Notice 17) 



This notice amends INIotor Vehicle Safety 
Standard No. 117, Retreaded Pneumatic Tires, 
to require additional permanent labeling for re- 
treaded tires. A notice of proposed rulemaking,- 
regarding this amendment was published Jan- 
uary 28, 1974 (39F.R. 3571). 

The permanent labeling required to be on each 
retreaded tire by this notice is tlie actual number 
of plies in the tire's sidewall and the actual 
number of plies in its tread area (if ditierent), 
and the generic name of each cord material used 
in the plies (both sidewall and tread area) of 
the tire. These requirements are in addition to 
the existing requirement that each retreaded tire 
be permanently labeled with its maximum per- 
missible load. 

Under the rule as hereby amended, retreaders 
do not have to relabel the ply and cord material 
information if it is retained on the casing side- 
wall through the retreading process. If the in- 
formation is removed during processing, however, 
it must be relabeled so that it will be perma- 
nently affixed to the completed tire. If the in- 
formation does not appear on the casing before 
retreading the casing may not be retreaded un- 
less the retreader can otherwise determine the 
correct information. 

The requirements for the permanent labeling 
of these information items are based specifically 
on section 201 of the National Traffic and Motor 
Vehicle Safety Act (15 U.S.C. 1421). The 
NHTSA did not include them in earlier versions 
of the standard, as it had concluded that their 
relationship to safety was not sufficient to justify 
permanent relabeling. In its opinion in NTDRA 
V. Brinegar 409 F.2d 31 (D.C. Cir., 1974), how- 
ever, the Court of Appeals stated that under the 
Safety Act the NHTSA was unauthorized to 



reach this conclusion, since Congress had deter- 
mined that i)ermaiient labeling requirements for 
actual number of plies and cord material must 
be included in the standard. The proposal of 
January 28, 1974, was issued as a direct result 
of that opinion. 

Many industry comments suggested that the 
NHTSA implement this aspect of the opinion 
by requiring the information to appear on com- 
pleted retreaded tires only when the information 
was retained through the retreading process. In 
cases where the information could not be re- 
tained, one comment, from the National Tire 
Dealers and Retreader's Association (NTDRA), 
suggested the use of affixed paper or plastic 
labels to supply the information, so it could be 
available to the purchaser at the time of pur- 
chase. Most of the comments, however, sug- 
gested that when the information could not be 
retained, no requirement should be imposed. 
These comments argued that for the agency to 
require otherwise would present substantial bur- 
dens on retreaders because of the difficulties in 
labeling all of the possible combinations of ply 
and cord material. The industry comments fur- 
ther pointed out that the permanent labeling 
problem will eventually disappear because of the 
amendment to Standard No. 109, which requires 
all tires manufactured after July 1, 1973, to con- 
tain required labeling between the tire's maxi- 
mum section width and bead. This labeling can 
be retained through the retreading process. 

After careful consideration of the issues pre- 
sented, the NHTSA has determined that it must 
issue the requirements in the form described. 
The agency is not unmindful that this will pre- 
vent the retreading of some casings otherwise 
usable, and will require relabeling of the infor- 



PART 571; S 117— PRE 23 



Effective: May 12, 1975 



mation on others. The NHTSA believes that to 
issue the requirements in the form suggested by 
the industry comments would not be consistent 
with the requirements of Section 201 of the 
Safety Act as interpreted by the Court of Ap- 
peals in NTDRA v. Bnnegar. To follow tlie 
industry suggestions would leave some tires 
without the information permanently labeled. 
It is imi30ssible to reconcile this result with the 
statutory requirement as interforeted by the 
Court. Nor can the agency, in conformity with 
the statute, establish an effective date so far in 
the future as to provide sufficient time for tires 
not containing necessary labeling to enter the 
retreading process. 

Based on its review of the record, the NHTSA 
does not find the requirement unreasonable or 
impracticable. Since the opinion in NTDRA v. 
Brinegar, methods have been developed which 
allow for the permanent labeling or relabeling 
of retreaded tires using a rubber medallion 
which is cured to the sidewall of the tire when 
the tire is in the mold. The comments indicate 
that this method is presently being used to 
permanently label not only a tire's maximum 
permissible load, as required, but its size, j)ly 
rating, and whether it is tubeless or tube type 
as well. The technology for this labeling ap- 
proach has been fully documented in retreading 
journals, and in communications to the docket. 
The NHTSA has furnished opinions stating 
that the use of the medallion conforms to the 
standard's permanent labeling requirements. 
The docket contains clear information regarding 
the cost of medallion labeling. Each label costs 
the retreader some 2.5 cents, and the record 
demonstrates that the cost of both label and 
application should not exceed 10 cents per tire. 
This differs from representations previously 
made regarding permanent labeling costs, which 
had been represented at $2.50 per tire. 

An additional problem raised in the comments 
is that adding the two information items greatly 
increases the labeling burden due to the number 
of possible combinations of information. The 
NHTSA does not believe the record supports 
this contention. According to NHTSA esti- 
mates, the variations in ply and cord material 
are relatively few in bias and bias-belted con- 



structions, with only six possible combinations 
of ply and cord material in the case of bias tires | 

and ten possible combinations in bias-belted con- 
struction. Together, these constructions would j 
necessitate a maximum of 1(5 labels. While 1 
NHTSA estimates show a greater number of 
possible combinations in the case of radial tires, M 
the record in this rulemaking suggests that few ^ 
radial tii-es are as yet being retreaded. It ap- 
pears most radials used for retreading will have 
been manufactured after July 1, 1973, and will 
have casings on which no relabeling would be 
needed. 

Furthermore, one comment, which claimed an 
increase from 67 to 2,000 possible labels, pre- 
sumed that all of the information (size, ply rat- 
ing, maximum permissible inflation pressures, 
tubeless or tube type, as well as maximum per- 
missible load, number of plies, and generic name 
of the cord materials) is placed on one label. 
However, tliere is nothing to in-ohibit the use of 
an additional label for both ply and cord ma- 
terial information, or even an additional label 
for each. Finally, relabeling is necessary only 
when the specified information is not retained 
through the retreading process. Estimates fur- 
nished by the industry and placed in the docket 
show that the information added by this amend- 
ment is not in a retainable position in only 1 out 
of 10 tires otherwise suitable for retreading. 
The requirement would presently affect a maxi- 
mum of 10% of retreaded tires, and by the time 
of its effective date that percentage should de- 
crease. 

Prior to this amendment, Standard No. 117 
required that on or after August 1, 1974, the 
only casings that could be used for retreading 
would be those tliat bore, originally molded into 
or onto their sidewalls, the symbol DOT, the tire 
size, and the actual number of plies or ply rat- 
ing. The notice of proposed rulemaking of 
January 28, 1974, proposed to delete the ply- 
rating alternative, making it necessary to use 
only casings that show the actual number of 
plies. It also proposed to add a requirement 
that the casings to be used would be only those 
that had originally been labeled with the generic 
names of their cord materials. These casing re- 
quirements were proposed on the assumption 



PART 571; S 117— PRE 24 



EfFecfive: May 12, 197S 



that the casing should already contain this in- 
formation if it is to appear on the completed 
retreaded tire. 

Several comments objected to these proposed 
requirements on the basis that they would cause 
a reduction in the number of retreadable casings 
in certain older and hard-to-find sizes. The 
NHTSA finds merit in these arguments, and the 
proposed requirements, that casings used for re- 
treading must be only those that are originally 
labeled with their actual number of plies and 
their cord materials, are not adopted. Eetreaded 
tires as they are finally produced must contain 
this information. But unlike "size" and "ply 
rating," which are crucial for safety and should 
only be based on original casing labeling, the 
NHTSA has decided that retreaders should be 
free to otherwise obtain information on the num- 
ber of plies and cord materials and then place it 
permanently on the tire. 

One objection raised in the comments with 
respect to the requirement that all casings bear 
the symbol DOT erroneously assumed that these 
requirements are part of the proposal. The re- 
quirement that on or after August 1, 1974, only 
DOT casings be retreaded was issued INIarch 23, 
1972 (37 F.R. 5950), because of the agency's 
concern over the continued use of older casings 



which were not manufactured to meet Standard 
No. 109. It was based on industry comments 
that a 6-year suisply of casings was required to 
meet industry needs. August 1, 1974, is 6 years 
from the date that all new tires were required 
to be labeled with the specified safety informa- 
tion which is the source of both affixed and 
permanent labeling under this standard. 

The existing casing requirements therefore re- 
main unchanged : the only casings that may be 
used for retreading are those that bear original 
permanent labeling of the DOT symbol, size, 
and the actual number of plies or ply rating. 

In light of the above, section 571.117 of Title 
49, Code of Federal Regulations (Motor "Vehicle 
Safety Standard No. 117), is amended .... 

Elective date: May 12, 1975. 

(Sees. 103, 112, 113, 114, 119, 201; Pub. L. 
89-563; 80 Stat. 718 (15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421 ) ; delegation of authority at 
49 CFR 1.51.) 

Issued on November 6, 1974. 

James B. Gregory 
Administrator 

39 F.R. 39882 
November 12, 1974 



PART 571; S 117— PRE 25-26 



i 



i 



^ 



MOTOR VEHICLE SAFETY STANDARD NO. 117 



Retreaded Pneumatic Tires 
(Docket No. 1-8; Notice 7) 



51. Scope. This standard specifies perform- 
ance, labeling, and certification requirements for 
retreaded pneumatic passenger car tires. 

52. Purpose. The purpose of this standard is 
to require retreaded pneumatic passenger car 
tires to meet safety criteria simOar to those for 
new pneumatic passenger car tires. 

53. Application. This standard applies to re- 
treaded pneumatic tires for use on passenger 
cars manufactured after 1948. 

54. Definitions. 

54.1 "Casing" means a used tire to which ad- 
ditional tread may be attached for the purpose 
of retreading. 

"Retreaded" means manufactured by a process 
in which a tread is attached to a casing. 

54.2 All terms defined in § 571.109 and 
S 571.110 are used as defined therein. 

55. Requirements. 
S5.1 Retreaded tires. 

55.1.1 Except as specified in S5.1.3, each re- 
treaded tire, when mounted on a test rim of the 
width specified for the tire's size designation in 
Appendix A of § 571.109, shall comply with the 
following requirements of § 571.109: 

(a) S4.1 (Size and construction). 

(b) S4.2.1 (General). 

(c) S4.2.2.3 (Tubeless tire resistance to bead 
unseating). 

(d) S4.2.2.4 (Tire strength). 

55.1.2 Except as specified in S5.1.3, each re- 
treaded tire, when mounted on a test rim of the 
width specified for the tire's size designation in 
Appendix A of § 571.109, shall comply with the 



requirements of S4.2.2.2 of § 571.109, except that 
the tire's section width shall not be more than 
110 percent of the section width specified, and 
the tire's size factor shall be at least 97 percent 
of the size factor specified, in Appendix A of 
§ 571.109 for the tire's size designation. 

55.1.3 Each retreaded tire shall be capable of 
meeting the requirements of S5.1.1 and S5.1.2 
when mounted on any rim in accordance with 
those sections. 

55.1.4 No retreaded tire shall have a size des- 
ignation, recommended maximum load rating, 
or maximum permissible inflation pressure that 
is greater than that originally specified on the 
casing pursuant to S4.3 of § 571.109, or specified 
for the casing in Table I. 

S5.2 Casings. 

55.2.1 No retreaded tire shall be manufactured 
with a casing— 

(a) On which bead wire or cord fabric is 
exposed before processing. 

(b) On which any cord fabric is exposed dur- 
ing processing, except that cord fabric that is 
located at a splice, i.e., where two or more seg- 
ments of the same ply overlap, or cord fabric 
that is part of the belt material, may be exposed 
but shall not be penetrated or removed to any 
extent whatsoever. 

55.2.2 No retreaded tire shall be manufactured 
with a casing— 

(a) From which a belt or ply, or part thereof, 
is removed during processing; or 

(b) On which a belt or ply, or part thereof, 
is added or replaced during processing. 



PART 571; S 117-1 



55.2.3 Each retreaded tire shall be manufac- 
tured with a casing that bears, permanently 
molded at the time of its original manufacture 
into or onto the tire sidewall, each of the fol- 
lowing: 

(a) The symbol DOT; 

(b) The size of the tire; and 

(c) The actual number of phes or ply rating 

55.2.4 [Reserved] 

S6. Certification and labeling. 

56.1 Except as specified in S6.2, each manu- 
facturer of a retreaded tire shall certify that his 
product complies with this standard, pursuant 
to section 114 of the National Traffic and Motor 
Vehicle Safety Act of 1966, by labeling the tire 
with the symbol DOT in the location specified 
in § 574.5 of this chapter. 

56.2 From June 1, 1973 to July 31, 1973, a 
manufacturer may certify compliance by affixing 
to the tread or sidewall of the tire, in such a man- 
ner that it is not easily removable, a label that 
states in letters not less than three thirty-seconds 
of an inch high: 

This retreaded tire was manufactured after 
June 1, 1973 and conforms to all applicable 
Federal motor vehicle safety standards. 

56.3 Labeling. 

S6.3.1 Each retreaded pneumatic tire manu- 
factured on or after June 1, 1973, shall be labeled, 
u. at least one location on the tire sidewall in 
letters and numerals not less than 0.078 inches 
high, with the following information: 

(a) The tire's size designation; 

(b) The tire's maximum permissible inflation 
pressure, either as it appears on the casing or as 
set forth in Table I; 



(c) The tire's maximum load, either as it ap- 
pears on the casing or as set forth in Table I; 

(d) The actual number of plies, ply rating, 
or both; 

(e) The word "tubeless" if the tire is a tube- 
less tire, or the words "tube type" if the tire is 
a tube-type tire; 

(f) If the tire is of bias/belted construction, 
the words "bias/belted", or the actual number of 
plies in the sidewall and the actual number of 
plies in the tread area. 

(g) The word "radial" if the tire is of radial 
construction. 

The information shall either be retained from 
the casing used in the manufacture of the tire, 
or may be labeled into or onto the tire during 
the retreading process, either permanently 
(through molding, branding, or other method 
that will produce a permanent label) or by the 
addition of a label that is not easily removable. 

S6.3.2 Each retreaded tire manufactured on 
or after May 12, 1975, shall bear permanent 
labeling (through molding, branding, or other 
method that will produce a permanent label, or 
through the retention of original casing label- 
ing) in at least one location on the tire sidewall, 
in letters and numbers not less than 0.078 inches 
high, consisting of the following information: 

(a) The tire's maximum permissible load, 

(b) The actual number of plies in the tire 
sidewall, and the actual number of plies in the 
tire tread area, if different; and 

(c) The generic name of each cord material 
used in the plies (both sidewall and tread area) 
of the tire. 



PART 571; S 117-2 







Table 


I-PLIES 








Tire Size 


2 Ply-4 Ply (4 Ply Rating) 


4 Ply (6 Ply Rating) 


4 Ply (8 Ply Rating) 


Maximum 


Maximum 


Maximum 


Maximum 


Maximum 


Maximum 




Load 


Inflation 
Pressure 


Load 


Inflation 
Pressure 


Load 


Inflation 
Pressure 


6.00-13 


1010 


32 


1080 


36 


1140 


40 


6.50-13 


1150 


32 


1230 


36 


1300 


40 


7.00-13 


1270 


32 


1360 


36 


1440 


40 


6.45-14 


1120 


32 


1200 


36 


1270 


40 


6.95-14 


1230 


32 


1310 


36 


1390 


40 


1 7.35-14 


1360 


32 


1450 


36 


1540 


40 


7.75-14 


1500 


32 


1600 


36 


1690 


40 


8.25-14 


1620 


32 


1730 


36 


1830 


40 


8.55-14 


1770 


32 


1890 


36 


2000 


40 


8.85-14 


1860 
970 


32 
32 


1990 
1040 


36 
36 


2100 
1105 


40 


! 

5.60-15 


40 


5.90-15 


1050 


32 


1130 


36 


1200 


40 


6.85-15 


1230 


32 


1320 


36 


1390 


40 


7.35-15 


1390 


32 


1480 


36 


1570 


40 


7.75-15 


1490 


32 


1590 


36 


1690 


40 


8.85-15 


1610 
1620 


32 
32 


1720 
1730 


36 
36 


1820 
1830 


40 


8.25-15 


40 


8.45-15 


1740 


32 


1860 


36 


1970 


40 


8.55-15 


1770 


32 


1890 


36 


2000 


40 


8.85-15 


1860 


32 


1980 


36 


2100 


40 


9.00-15 


1900 
1970 


32 
32 


2030 
2100 


36 
36 


2150 
2230 


40 


9.15-15 


40 


8.90-15 


2210 


32 


2360 


36 


2500 


40 



PART 571; S 117-3 



Table I-PLIES-Continued 





2 Ply-4 Ply (4 Ply Rating) 


4 Ply (6 Ply Rating) 


4 Ply (8 Ply Rating) 


Tire Size 


Maximum 


Maximum 


Maximum 


Maximum 


Maximum 


Maximum 




Load 


Inflation 
Pressure 


Load 


Inflation 
Pressure 


Load 


Inflation 
Pressure 


A70-13 _ 


1060 


32 


1130 


36 


1200 


40 


D70-13 


1320 


32 


1410 


36 


1490 


40 


D70-14 


1320 


32 


1410 


36 


1490 


40 


E70-14 


1400 


32 


1490 


36 


1580 


40 


F70-14 


1500 


32 


1610 


36 


1700 


40 


G70-14 


1620 


32 


1730 


36 


1830 


40 


H70-14 


1770 


32 


J1890 
1980 


36 


2010 


40 


J70-14 


1860 


32 


36 


2100 


40 


L70-14 


1970 


32 


2100 


36 


2230 


40 


C70-15 


1230 

1320 


32 
32 


1320 
1410 


36 
36 


1390 

1490 


40 


D70-15 


40 


E70-15 


1400 


32 


1490 


36 


1580 


40 


F70-15 


1500 


32 


1610 


36 


1700 


40 


G70-15 


1620 


32 


1730 


36 


1830 


40 


H70-15 


1770 


32 


1890 


36 


2010 


40 


J70-15 


1860 


32 


1980 


36 


2100 


40 


K70-15 


1900 


32 


2030 


36 


2150 


40 


L70-15 


1970 


32 


2100 


36 


2230 


40 



PART 571; S 117-4 



Table I-PLIES-Continued 

2 Ply-4 Ply (4 Ply Rating) 4 Ply (6 Ply Rating) 

Tire Size Maximum Maximum Maximum Maximum 

Load Inflation Load Inflation 

Pressure Pressure 

165-13 1050 32 1130 36 

175-13 1150 32 1240 36 

185-13 1270 32 1390 36 

155R13 950 32 1015 36 

155R14 1010 32 1080 36 

155R15 1015 32 1085 36 

165R13 1010 32 1080 36 

165R14 1120 32 1200 36 

165R15 1130 32 1200 36 

175R14 1230 32 1310 36 

185R14 1360 32 1450 36 

185/70R13 1090 32 1140 36 

145-14* 865 32 905 36 

145-15 895 32 940 36 

195-15 1550 32 1680 36 

205-15 1700 32 1840 36 

* Dash Radial-Not an "R" Radial 



4 Ply (8 Ply Rating) 

Maximum Maximum 

Load Inflation 

Pressure 



1200 


40 


1350 


40 


1510 


40 


1075 


40 


1140 


40 


1150 


40 


1140 


40 


1270 


40 


1270 


40 


1390 


40 


1540 


40 


1190 


40 


935 


40 


975 


40 


1820 


40 


2000 


40 



36 F.R. 7315 
April 17, 1971 



PART 571; S 117-5 



Effective: February 1, 1971 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 118 

Power-Operated Window Systems for Passenger Cars and Multipurpose Passenger Vehicles 

(Docket No. 69-1 la) 



In May 1968 the Director of the National 
Highway Safety Bureau issued a public advis- 
ory, stating that numerous cases of injury and 
death from accidental operation of power win- 
dows had been reported to the Bureau. He 
warned that many of those injuries and deaths 
had occurred because power windows could be 
closed when the ignition switch was off. In the 
advisory, the Director cautioned owners of ve- 
hicles with power-operated windows to have the 
wiring adjusted to prevent closure of the win- 
dows when the ignition switch is off. 

It has been determined that the interests of 
motor vehicle safety require the imposition of a 
safety standard which will reduce, if not elimi- 
nate, the toll of deaths and injuries resulting 
from accidents involving power-operated win- 
dows. 

A notice of proposed rule making relating to 
power-operated window systems in passenger 
cars and multipurpose passenger vehicles was 
published in the Federal Register on August 23, 
1969 (34 F.R. 13608). Comments were requested 
concerning two objectives of the proposal: (1) 
To minimize the likelihood of personal injury 
or death occurring when a person is caught be- 
tween a closing window and the frame, channel 
or seal, and (2) to insure that vehicle occupants 
can make emergency exits from vehicles equipped 
with power-operated windows in the event of a 
severe accident. 

The comments received have been given careful 
consideration in the formulation of the safety 
standard issued today. To achieve the first major 
objective it was proposed that a power-operated 
window, once opened, not close when the igni- 
tion key of the vehicle is not in the "on" or 
"start" position. This proposal would have pro- 



hibited operation of windows when the key was 
in the "accessory" position, a position provided 
to avoid battery discharge and possible damage 
to the electrical system. The proposal would 
also have prohibited activation of power tailgate 
windows from the exterior of the vehicle. Sev- 
eral commenters objected that the proposal would 
in these respects prohibit widely accepted con- 
venience features without corresponding safety 
benefits. These comments have been determined 
to have merit, and the standard as presently 
issued has been modified to require that a power- 
operated window system not be operative, except 
by muscular force or by operating an outside 
lock, when the key is removed from the ignition 
lock or is in an off position. This permits opera- 
tion of windows with the key in the "accessory" 
position, as well as by a key-locking system on 
the exterior of the vehicle. 

To achieve the second objective, it was pro- 
jxjsed that a control be required that would open 
power-operated windows from inside the pas- 
senger compartment of the vehicle, regardless of 
the key position. Allowance of such a control, 
however, might tend to defeat the first major 
objective, and also make it easier for thieves to 
enter a locked vehicle. Further, an accident se- 
vere enough to jam a vehicle door very likely 
would be severe enough to jam the window in 
its channel or to interfere with the power source 
for emergency operation of the window. For 
these reasons this proposal has not been adopted 
in Standard No. 118. The standard does, how- 
ever, permit installation of master control 
switches for overriding control of power-operated 
windows when the ignition key is in a position 
other than off. 



PART 571; S 118— PRE 1 



Effective: February 1, 197) 



Comments indicated an assumption that power- 
operated interior partitions were covered, as they 
were intended to be, though not specifically men- 
tioned in the preamble of the proposal. To 
insure that there is no ambiguity on the point. 
Standard No. 118 includes partitions in the re- 
quirements. 

The subject matter covered by this rulemaking 
action is being adopted at this time because it 
has been detennined that it is feasible and that 
it can be implemented at an early date. The 
notice of proposed rule making upon which this 
rulemaking action is based was issued in con- 
junction with an advance notice of proposed rule 
making (34 F.R. 13609, Aug. 23, 1969) on power- 
operated window systems that dealt with the 
subject of mechanisms that would interrupt, stop, 
or reverse the direction of the window when a 
predetermined force is exerted on an object be- 
tween the glazing and the frame, channel, or 



seal upon which it closes, and other fail-safe 
considerations. The advance notice involved 
engineering and economic problems of a substan- 
tial magnitude. Those problems and their solu- 
tions are undergoing further study and will be 
given consideration for rulemaking based on the 
results thereof. 

In consideration of the foregoing, 49 CFR 
571.21, Federal Motor Vehicle Safety Standards, 
is amended by adding Standard No. 118, Power- 
Operated Window Systems .... 

Effective date : February 1, 1971. 

Issued on July 17, 1970. 

Douglas W. Toms, 

Director, 

National Highway Safety Bureau 

35 F.R. 11797 
July 23, 1970 



PART 571; S 118— PRE 2 



d 



Effective: July 29, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 118 

Power-Operated Window Systems 
(Docket No. 74-1; Notice 3) 



The purpose of this notice is to amend Stand- 
ard No. 118, Power-Operated Window Systems, 
49 CFR 571.118, to permit the operation of 
power windows under certain conditions when 
the ignition is not in the "on" position. 

On September 23, 1974, the agency published 
a notice (39 F.R. 34062) proposing to allow the 
operation of power windows, when the key that 
controls the vehicle's engine is in the off position 
or is removed from the lock, only in circum- 
stances where (1) only muscular force is used, 
or (2) a key-locking system on the vehicle's ex- 
terior is activated, or (3) a door that has no 
frame meeting the upper edge of the closed 
window is opened a specified amount and a 
switch separate from the normal power window 
switch is activated. 

Nine comments were submitted to the docket, 
all of which approved of the basic proposal to 
allow operation of the power windows when the 
vehicle engine is not running. General Motors, 
who suggested the proposal as it was published, 
supported its adoption. However, most of the 
commenters objected to the proposed provision 
that a separate switch be required to operate a 
window when the door is open to a degree suf- 
ficient to permit a ball the size of a child's head 
to pass between the top edge of the fully closed 
window and the vehicle's roof rail. The objec- 
tion was based on a contention that the separate 
switch provision was design restrictive and not 
necessary from a safety standpoint. According 
to the comments, required use of a separate 
switch for activation of the windows when the 
doors are opened would not assure a higher level 
of safety than use of the normal power activa- 
tion switch. 



The NHTSA finds merit in commenters argu- 
ments. It is the considered opinion of the agency 
that the absence of a separate switch requirement 
will have no effect on the safety of the power- 
operated window system since no switch would 
be capable of activation unless the vehicle's door 
were opened to the specified distance. For this 
reason the proposed separate switch requirement 
is deleted. Manufacturers will thus be free to 
install whatever type of activation system they 
wish, as long as the criteria of S3(c) are satis- 
fied. 

In addition, the description of the locations 
between which the test ball must fit appears to 
need clarification. It is the agency's intention 
that the ball be capable of passing between the 
upper rear corner of the fully closed window 
and the vehicle's roof rail. Therefore, the term 
"trailing edge" in S3(c) is changed to "upper 
rear corner." 

In consideration of the foregoing, S3, of 
Standard No. 118, Power-Operated Window 
Systems (49 CFR 571.118) is amended. . . . 

Effective date: Because this amendment re- 
lieves a restriction and imposes no additional 
burden on any person, it is found for good cause 
shown that an immediate effective date is in the 
public interest. 

(Sees. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR 1.51.) 



Issued : July 23, 1975. 



James B. Gregory 
Administrator 

40 F.R. 31773 
July 29, 1975 



PART 571; S 118— PRE 3-4 



MOTOR VEHICLE SAFETY STANDARD NO. 118 

Power-Operated Window Systems 
(Docket No. 69-1 1a) 



51. Purpose and scope. This standard speci- 
fies requirements for power-operated window 
and partition systems to minimize the hkelihood 
of death or injury from their accidental opera- 
tion. 

52. Application. This standard applies to 
passenger cars and multipurpose passenger ve- 
hicles. 

53. Requirements. When the key that con- 
trols activation of the vehicle's engine is in an 
off position or is removed from the lock, no 
power-operated wandow or partition shall be 
movable except— 

(a) By muscular force unassisted by a power 
source within the vehicle; 



(b) Upon activation by a key-locking system 
on the exterior of the vehicle; or 

(c) In the case of a door that does not have 
a frame that meets the upper edge of the win- 
dow in its closed position, by activation of a 
switch that is energized only when the door is 
opened wide enough to permit a ball 8 inches 
in diameter to pass between the upper rear cor- 
ner of the window in its fully raised position 
and the vehicle's roof rail. 



35 F.R. 11797 
July 23, 1970 



PART 571; S 118-1 



Effective: September 1, 1974 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 119 

New Pneumatic Tires for Vehicles Other Than Passenger Cars 
(Docket No. 71-18; Notice 3) 



This notice establishes a new Motor vehicle 
safety standard No. 119 New pneumatic tires for 
vehicles other than passenger cars, 49 CFR 
571.119, which specifies performance and label- 
ing requirements for new pneumatic tires de- 
signed for highway use on multipurpose 
passenger vehicles, trucks, buses, trailers and 
motorcycles manufactured after 1948, and which 
requires treadwear indicators in tires, and rim 
matching information concerning those tires. 

Notices of proposed rulemaking on this sub- 
ject were published on August 5, 1971 (36 F.R. 
14392). and July 8, 1972 (37 F.R. 13481). 

The July 1972 notice proposed that, instead of 
including the voluminous "tire tables" of tire 
size designations, maximum loads and inflation 
pressures, and dimensions in the standard, the 
manufacturers continue as at present to use the 
industry association tire and rim manuals for 
the purpose of product standardization. Since 
the only tire characteristics relevant to the safety 
performance tests of the standard are general 
tire type, speed restrictions, maximum load rat- 
ing, load range, and rim diameter, all of which 
are readily available or labeled on the tire itself, 
the tables are not necessary for the performance 
requirements. To prevent these private associa- 
tions from having ultimate regulatory power 
over individual manufacturers, a provision was 
included in the proposal by which a manufac- 
turer who wished to differ from the values in 
the association tables could do so by providing 
separate information to the NHTSA, to his deal- 
ers, and to the public upon request. To prevent 
the under-rating of tires of an established size 
designation, another provision would prohibit 
the assignment by a manufacturer of a maximum 
load rating to a particular tire size designation 



that is lower than the load rating already pub- 
lished elsewhere for that tire size designation. 

Many domestic tire manufacturers objected to 
lack of tire tables on the grounds that it in effect 
endorsed non-standardization of tire specifica- 
tions. They and some representatives of the 
trucking industry speculated that there might 
be danger of mis-match arising from the pro- 
duction of tires whose dimensions deviate sub- 
stantially from the published dimensional 
specifications for tires of that size designation. 
Several of the domestic manufacturers recom- 
mended inclusion of the (American) Tire and 
Rim Association tables in the standard because 
of the experience that domestic manufacturers 
have with road conditions in the United States. 

Other manufacturers, however, supported the 
deletion of tire tables for several reasons. They 
argued that a single standard would discourage 
innovation in tire design and suggested that the 
complexities of selection and maintenance of 
truck tires could not be reduced to a single table 
of values. They asserted that standardized new- 
tire dimensions do not eliminate the need to 
measure tires for proper dual matching, because 
tires wear differently in use and thereafter rarely 
match new or used tires of the same size. 

Upon consideration of all relevant informa- 
tion, the NHTSA has concluded that the posi- 
tion taken in the proposal is sound, and it is 
adopted in the rule. The inclusion in the Code 
of Federal Regulations of load-inflation and di- 
mension tables for every road tire sold in this 
coimtry (they presently are included in Standard 
109 only for passenger cars) would be a vastly 
cumbersome process, not only in its inception but 
as a continuous maintenance task. The NHTSA 
finds no justification at this time for undertaking 



PART 571; S 119— PRE 1 



Effective: September 1, 1974 



to monitor substantively the manufacturer pro- 
cesses and testing that lead to the continual 
changes in the standard association tables, so its 
function in this regard would be largely clerical. 
The point is not, as the (U.S.) Rubber Manu- 
facturers Association asserted, primarily one of 
"administrative convenience". It is that no 
justification has been found for locking both the 
government and the world tire industry into a 
restrictive and unwieldy system by which the 
Code of Federal Eegulations is formally 
amended every time a manufacturer decides to 
add a tire size, or change the load rating or di- 
mensional specifications of one of its tires. There 
are many reasons to avoid over-regulation; 
"administrative convenience" is among the least 
of them. 

This agency has no intent to dilute the stand- 
ardizing function of the trade-association table 
systems that presently are used to provide neces- 
sary tire and rim information to dealers and 
users. These systems monitor the safety aspects 
of tire dimension and load rating satisfactorily 
now without government regulation, and the 
NHTSA expects that they will continue to do so. 
No evidence has been presented of under- or 
over-sizing of tires that would warrant the in- 
stitution of a massive government regulatory 
program in that area. If such a practice should 
arise in the future to a degree that constitutes 
a public hazard, the NHTSA has ample author- 
ity to deal with it specifically, as a safety-related 
defect, and prospectively, under its rulemaking 
powers. 

The argument that the agency should include 
only the domestic Tire and Rim Association 
tables, thereby requiring foreign tire manufac- 
turers to build tires under the specifications, and 
presumably the approval, of the domestic asso- 
ciation, is found to be without merit. The word- 
ing and the legislative history of the National 
Traffic and Motor Vehicle Safety Act show a 
clear Congressional intent to give evenhanded 
treatment to domestic and foreign manufactur- 
ers of motor vehicles and equipment, and this 
has always been the policy of the NHTSA. This 
agency has no evidence that foreign associations 
or manufacturers lack the information necessary 
to produce safe tires for the American market. 



Finally, the argument that the agency could 
or should by some means prevent "proliferation" 
of new tire sizes is without substance. No con- 
crete justification has been presented for at- 
tempting to limit the introduction of new tire 
sizes, and to date no significant safety problems 
have been found caused by the addition of new 
tire sizes. The NHTSA assumes that the com- 
petition and consumer demand forces of the 
private sector will operate as in other areas of 
our economy, to produce a satisfactory product 
population. 

The criteria for tire failure in the endurance 
and high speed laboratory tests have been sub- 
stantially modified from those of the proposal 
in response to comments to this docket and 
Docket 71-10, Notice 2 (37 F.R. 19381, Septem- 
ber 20, 1972), which proposed identical changes 
in the passenger car tire failure criteria. This 
regulation adopts the same failure criteria as 
were adopted in final form for passenger car 
tire tests on September 28, 19T3 (38 F.R. 27050), 
and relies on several new and revised definitions 
found in Standard 109. The preamble to the 
passenger car tire amendment fully explains the 
modifications made, and it is only noted here 
that the changes are substantially in agreement 
with manufacturers' requests to specify the tire 
failures with particularity. A pre-test inspec- 
tion has been added to discover failures in con- 
struction evident without dynamic testing. 
Additionally the required air pressure following 
the test run has been raised to 100 percent of the 
original pressure. 

Several comments questioned the inclusion of 
all non-passenger car tires in one standard, 
pointing out that tire design differs radically to 
optimize desirable characteristics for each vehicle 
type and application. However, this standard 
does not attempt to measure the optimum char- 
acteristics of each type of non-passenger tire. 
This standard only establishes minimum per- 
formance characteristics which any type of tire 
must satisfy to be safely used on public high- 
ways. Passenger car tires have been subjected 
to such a standard in the past and this proposal 
extends a comparable minimum standard to all 
other tire types designed for highway use. The 
requirements recognize the design differences 



PART 571; S 119— PRE 2 



Effective: September 1, 1974 



between tire types by establishing different test 
values for different tire types, size, construction, 
load ranges, and speed restrictions. 

Comments to the docket requested physical 
tolerances and related accommodations for test 
purposes. These arise from misunderstanding 
of the legal nature of the safety standards, which 
are performance levels that each vehicle or item 
of motor veliicle equipment must meet, and not 
instructions for manufacturer testing. The tem- 
perature conditions for tire testing have been 
reworded to reflect the legal meaning and the 
NHTSA testing practices relative to tire stand- 
ards. The proposed standard would make clear 
that the tire must be capable of meeting the 
requirements when tested at any ambient tem- 
perature up to 100° F. The legal significance 
of this requirement is explained in a general 
provision of Part 571, § 571.4, Explanation of 
image. In NHTSA compliance testing, the am- 
bient temperature would be maintained in a 
range between 90° and 100° F., and any test 
failure under those conditions would be consid- 
ered a failure to meet the standard. ^Nlanufac- 
turer testing should be directed at proving the 
tire's capability in the exercise of due care, by 
testing under conditions at least as adverse as 
any that could be established in accordance with 
these procedures. 

The trucking industry questioned the advis- 
ability of labeling maximum inflation and load 
rating on the tire because it appeared to prohibit 
the adjustment of pressures to road conditions. 
The purpose of the labeling is to establish test 
values for the tire and to warn the user of the 
tire's maximum capabilities . The label does not 
prohibit adjustment of pressure to suit road con- 
ditions or prevent a manufacturer from recom- 
mending other inflation-load combinations on the 
tire or in accompanying literature to suit specific 
circumstances. 

European manufacturers objected to the re- 
quirement that load rating be indicated by a 
"load range" index not in world-wide use. The 
primary purpose of the load range index is to 
indicate categories of strength within the size 
designations, for user information and test pur- 
poses. It should be understood that a manu- 
facturer may use whatever additional systems 
he chooses to indicate his assessment of tire 



strength. Information such as metric equiv- 
alents and ply ratings, for example, may be 
added to sidewall labeling as long as the required 
information appears in the required format on 
the tire. 

Several manufacturers suggested that labeling 
appear on only one side of a tire when both sides 
of the tire, as mounted, will be available for 
inspection. Accordingly, motorcycle tires must 
now be labeled on one side only, but the inac- 
cessibility of both sidewalls on truck and bus 
tires for visual inspection precludes one-sidewall 
labeling of these categories. 

Despite this inaccessibility, however, the iden- 
tification code appears on one sidewall only, be- 
cause placing the ID slug in the upper half of a 
hot process mold is a difficult and dangerous 
operation. In response to another labeling re- 
quest, the DOT symbol must not be placed on 
the tire before the effective date of the standard. 

Several manufacturers argued for greater de- 
sign freedom in the placement of treadwear in- 
dicators because the proposed locations could 
generate useless, arbitrary information when ap- 
plied to "lug" tread designs. In response, tread 
"groove", "width", and "depth" have been de- 
fined so that the treadwear indicators are placed 
to indicate wear in that portion of the tread 
which contacts the ground. 

Several comments on the endurance require- 
ment requested lower test loads and speed to 
approximate actual driving conditions on flat 
surfaces. The NHTSA does not utilize the lab- 
oratory test wheel to simply approximate road 
conditions but rather to apply strictly controlled 
amounts of stress to moving tires over long 
periods in order to measure a minimum level of 
performance. Industry testing established these 
values and they have been independently verified 
in NHTSA's Safety Systems Laboratory as an 
accurate gauge of tire endurance. Another 
manufacturer expressed confusion about the ap- 
propriate endurance test standards for mining 
and logging tires. These tires are generally 
speed-restricted tires and should be tested in 
accordance with the values established in Table 
III for all other speed-restricted tires. 

In response to another comment, it should be 
noted that test accuracy also requires a stand- 



PART 571; S 119— PRE 3 



Effective: September T, 1974 



ardized test wheel diameter, because the wheel's 
curvature directly affects a tire's ability to ab- 
sorb strain. 

Several manufacturers requested elimination 
of the pressure reading following the 47-hour 
run so that they could run the tire to destruction 
in accordance with industry test practices with- 
out stopping to make the measurement. This 
request can not be granted because the new pro- 
cedures for evaluating tire failure necessitate 
stopping after the run to inspect the tire, in 
addition to stopping to take a pressure reading. 

Comments raised the validity of the strength 
test when applied to tires incorporating recent 
innovations in tire design. It appears that re- 
cent changes in the construction of passenger 
car tires, especially the addition of belts under 
the tread, have tended to make the strength test 
specified in Standard 109 obsolete (38 F.R. 1055, 
January 8, 1973). However, the construction of 
non-passenger tires permits accurate measure- 
ment of tire strength without the "bottoming 
out" problem noted in the comments, if the 
proper plunger size and breaking energy value 
are used. A differential in breaking energy 
value between tubed and tubeless tires accom- 
modates the smaller dimensions of the newer 
tubeless configurations that replace tube tires 
of the same load range. The "light truck" cate- 
gory accommodates the different design and con- 
struction materials which manufacturers use in 
these tires designated for this specialized service. 
The NHTSA does not agree that lower breaking 
energy values should apply to tires under 7 
inches in section width as suggested in one com- 
ment, because these tires are no smaller than 
typical passenger car tires subjected to similar 
testing and similar conditions on the highway. 
In response to another comment, the NHTSA 
has concluded that differences in the construc- 
tion of steel-belted tires are not sufficient to 
justify lower energy values in the plunger test 
similar to those extended to rayon tires. 

Objections to the high speed performance re- 
quirements questioned the testing of all light 
tires (load ranges A, B, C, and D) under the 
same high-speed conditions. The NHTSA has 



eliminated speed-restricted tires from the re- 
quirements but will maintain high-speed require- 
ments for all motorcycle, trailer, and truck tires. 
While it is true that these tires are specially 
constructed for their purpose and often are 
mounted on vehicles marked with speed restric- 
tions, there is no assurance that these tires will 
be properly utilized. The difficulty lies with 
drivers who ignore rental trailer speed limits, 
subject boat or mobile home trailer tires to higher 
than recommended speeds, attempt to improve 
the performance of their low speed motorcycles, 
or drive trucks equipped with light truck tires 
at high speed on the highway. This probability 
of abuse creates a safety problem which can be 
met by requiring these tires to withstand such 
high speed abuse. Load range D tires over 15 
inches in section width are presently subject to 
the high speed test but may be reclassified on 
the basis of future test experience. 

Comments to the docket objected to the pro- 
posed effective date and requested up to 18 
months leadtime following issuance of the stand- 
ard on the grounds that the large variety of 
tires to be certified requires substantial enlarge- 
ment of test facilities. This standard has been 
in various proposal stages for 4 years, however, 
which has provided the tire industry ample op- 
portunity to make plans for the acquisition and 
installation of test facilities and therefore lead- 
time of 9 months is considered adequate. 

In consideration of the foregoing, a new 
Standard 119, New pneumatic tires for vehicles 
other than passenger cars, is added to Part 571 
of Title 49, Code of Federal Eegulations, to 
read as set forth below. 

Effective date : September 1, 1974. 

(Sees. 103, 112, 113, 114. 119, 201, Pub. L. 
89-563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 
1403, 1407, 1421; delegation of authority at 49 
CFR 1.51.) 

Issued on November 5, 1973. 

James B. Gregory 
Administrator 

38 F.R. 31299 
November 13, 1973 



PART 571; S 119— PRE 4 



Effective: March I, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 119 

New Pneumatic Tires for Vehicles Other than Passenger Cars 

(Docket 71-18; Notice 5) 



This notice amends Standard 119, Neiv pneu- 
matic tires for vehicles other than passenger cars, 
49 CFR 571.119, by changing the effective date 
from September 1, 1974, to March 1, 1975. 

A major concern of manufacturers comment- 
ing on Standard 119 as it was published in final 
form on November 13, 1973, (38 F.R. 31299), 
with a September 1, 1974, effective date, was the 
limited leadtime in which to modify tire molds 
and certify the conformity of tires. Correct use 
of the DOT symbol, lettering height, and clari- 
fication of treadwear indicator language required 
attention before the changeover process could 
begin. 

Manufacturers requested up to 11 months' ad- 
ditional leadtime in view of these difficulties. 
Amendments have been proposed that would re- 
solve these specific problems. Because the range 
of non-passenger car tires is so great, however, 
the National Highway Traffic Safety Adminis- 
tration has determined that even with these 
changes an additional 6 months' leadtime is 
justified to accomplish full certification. 



Other matters raised by petitions for recon- 
sideration are presently under consideration and 
will be answered in accordance with the proce- 
dures of 49 CFR 553.35, Petitions for reconsid- 
eration. 

In consideration of the foregoing, Standard 
119 (49 CFR §571.119) is amended by changing 
the effective date of September 1, 1974, to March 
1, 1975. 

Because this amendment creates no additional 
burden, and because changeover scheduling must 
begin immediately, it is found for good cause 
shown that notice and public procedure thereon 
are impracticable and unnecessary. 

(Sees. 103, 119, 201, Pub. L. 89-563, 80 Stat. 
718, 15 U.S.C. 1392, 1407, 1421; delegation of 
authority at 49 CFR 1.51.) 

Issued on January 29, 1974. 

James B. Gregory 
Administrator 

39 F.R. 4087 
February 1, 1974 



PART 571; S 119— PRE 5-6 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 119 



New Pneumatic Tires for Vehicles Other than Passenger Cars 

(Docket 71-18; Notice 6) 



This notice responds to petitions for reconsid- 
eration on Standard 119, New pneumatic tires 
for vehicles other than passenger cars, 49 CFR 
571.119, published November 13, 1973 (38 F.R. 
31299). In response to comments by twelve tire 
manufacturers and trade associations, the defini- 
tions, labeling, and performance provisions of 
the standard are amended in several respects. 

Justification for Issuance of Standard 119 
The Rubber Manufacturers Association 
(RMA), supported by most domestic tire manu- 
facturers, petitioned for withdrawal of Standard 
119 on the grounds that promulgation of the 
standard did not satisfy the criteria for the es- 
tablishment of Motor Vehicle Safety Standards 
set out in § 103 of the National Traffic and Motor 
Vehicle Safety Act of 1966. Section 103(f) of 
the Act requires that the formulation of a stand- 
ard include consideration of its appropriateness 
for particular items of motor vehicle equipment, 
relevant safety data, and the extent to which it 
will contribute to carrying out the purposes of 
the Act. As formulated a standard must be 
practicable, meet the need for motor vehicle 
safety, and be stated in objective terms. 

In petitioning for withdrawal of Standard 119 
for failure to "meet the need for motor vehicle 
safety," the RMA and those tire manufacturers 
who support its position effectively assert that 
no tire safety hazard exists which can be met by 
Standard 119. The National Highway Traffic 
Safety Administration (NHTSA) does not agree. 
Congress recognized a tire safety problem. 
The Senate held hearings on and considered a 
bill devoted totally to tire safety (S1643). The 
House included a separate title in H.R. 13228 to 
emphasize tire safety as a particularly important 
area for the issuance of safety standards. 



In a number of l)ills which liaAC l)eeii in- 
troduced in botli Houses as well as in a bill 
which has passed the Senate (S.2669) the 
necessity for standards for tires was consid- 
ered as an inde]5endent problem and without 
reference to its relationship to the total 
traffic safety problem. S.2669 is confined 
only to the improvement of tires for passen- 
ger cars and station wagons. The committee 
decided that although tires are a highly im- 
portant part of the total traffic safety prob- 
lem they are, nevertheless, an integral part 
of it and should be dealt with in the context 
of the problem and not in a piecemeal 
fashion. . . . 

However the committee did feel that it was 
necessary to emphasize this aspect of the 
safety problem and to establish certain spe- 
cific requirements which should be contained 
in the Secretary's standards on tires, (em- 
phasis supplied) H.R. Rep. No. 1776, 89th 
Cong., 2d Sess. 32 (1966). 

On the House floor. Representative Springer 
detailed the effect of the legislation on motor 
vehicle equipment. 

Obviously, the most important piece of 
equipment which comes to mind is the tire. 
The other body treated this subject in sepa- 
rate legislation, but it seems to me, and it 
did to our committee, that tire standards 
must be part and parcel of any legislation 
which seeks to impose standards of safety 
for the cars on the highway. Consequently, 
a portion of the bill was devoted specifically 
to this subject. It requires minimum stand- 
ards for all tires, and then sees to it that the 
buyer will have all the information he needs 
to make a decision as to the tire he needs. 



PART 571; S 119— PRE 7 



Effective: March 1, 1975 



112 Cong. Rec. 18,780 (daily ed. Aug. 17, 
1966) 

Congress showed particular interest in passen- 
ger car tires, but did not limit the legislation to 
them, as suggested by Firestone in its petition 
for reconsideration. As tlie House report notes, 
Title II represents a broadening of the tire 
safety issue from passenger cars and station 
wagons. The language of Title II refers to tires 
of "each motor vehicle" and to a uniform tire 
quality grading system ''for motor vehicles." 
Section 204 is devoted to regrooved tires which 
are commonly utilized on non-passenger cars. 

The NHTSA has concluded that tlie tire safety 
problems recognized by Congress can best be met 
by Standard 119. The standard requires label- 
ing and tire-rim matching information to aid 
proper application of the tire, and minimum 
performance levels to ensure adequate designed- 
in safety for normal use and predictable abuse 
on the road. The standard is directed at misuse 
of tires as well as their correct use. 

It is true that Bureau of Motor Cairier Safety 
statistics indicate that i)rofessional maintenance, 
cost consciousness, and frequent state inspections 
result in a lower than normal number of tire 
failures on interstate haulers. These figures, 
however, are not representative of tire conditions 
throughout the multipurpose passenger vehicle 
(MPV), truck, bus, motorcycle, and trailer cate- 
gories. Congress mandated minimum tire safety 
standards although it was aware that tire failure 
statistics were difficult to isolate, realizing that 
tire design, while not a major cause of failures 
in well-maintained tires, could offer a margin of 
safety where tires are misused. Hearings on 
S.1634 Before the Senate Commerce Committee 
on Tire Safety, 89th Cong., 1st Sess., ser. 89-37 
at 41 (1965) ; Hearings on S.3005 Before Senate 
Commerce Committee on Traffic Safety, 89th 
Cong., 2nd Sess., ser. 89-49 at 158, 159 (1966). 
In its formulation of the standard, the NHTSA 
considered data which showed that worn and 
misapplied tires create a significant safety haz- 
ard. Standard 119 ensures that tlie informa- 
tion required by Congress to be on tires, along 
with additional tire-rim matching information 
and treadwear indicators, are available to the 
unknowledgeable individual who must select, 



maintain, and replace non-passenger tires pe- 
riodically. The RMA itself argued for the in- 
clusion of load-rating information in this stand- 
ard as an effective means to eliminate the 
dangers of proliferation and misapplication of 
tire sizes. In the area of tire design, the mini- 
mum performance levels in Standard 119 ensure 
a margin of safety for persons who may mis- 
apply or abuse tires despite the label information 
and treadwear warnings. 

The NHTSA experience with performance 
standards for passenger car tires also supports 
Standard 119 rulemaking. Since the beginning 
of certification testing by tlie manufacturers and 
compliance testing by the NHTSA, the percent- 
age of test failures lias dropped from approxi- 
mately 5.6% to less than 1%. At the same time 
88 recalls of 1,436,118 tires have removed from 
tlie road substantial numbers of tires which could 
not be shown in tlie exercise of due care to be 
able to meet the minimum requirements. Stand- 
ard 119 has similar performance tests, calculated 
to produce close surveillance of test failure per- 
centages and recalls when a faulty tire design is 
identified. The performance test levels vary ac- 
cording to tire type to ensure that the standard 
is reasonable, practicable, and appropriate for 
the particular tire design in its intended service 
application. 

The NHTSA has found that Standard 119 will 
weed out faulty tire design and promote safety. 
The test values of Standard 119 were originally 
proposed by industry and checked by the NHTSA 
at its Safety Systems Laboratory. The RMA 
conducted a similar series of tests at that time 
and later endorsed the requirements as modified 
in minor respects: 

The laboratory tests and values in the pro- 
posed FMVSS 119 as amended by our com- 
ments would set standards of performance 
that would enable the industry to design 
tires that would ensure safe operation on the 
highways. Comment #4 to Docket 1-5, 
Notice 7 (p 6). 

By reference to H & H Tire Company v. 
United States Department of Transportation^ 
471 F2d 350 (7th Cir 1972), the RMA and Fire- 
stone raised the issue of Standard 119's prac- 



PART 571; S 119— PRE 8 



Effective: March 1, 1975 



ticability. This requirement, at § 103(a) of the 
Act, was interpreted in HdH to mean that the 
NHTSA must determine the technological and 
economic consequences of the standard on the 
regulated industry. In that case the Court de- 
termined that the retread tire industry could be 
destroyed by the expense of major product rede- 
sign or the loss of business which could result 
from passing on these costs in higher prices to 
the typical retread consumer. The Court also 
pointed out that the retread consumer might use 
older worn tires longer than previously and 
thereby in effect increase the tire hazard problem 
in response to Standard 117. 

In contrast, the NHTSA has determined that 
compliance with Standard 119 does not require 
significant or impracticable technological change. 
Tests run at the Safety Systems Laboratory in- 
dicate that a sampling of production-run tires 
can meet the required performance levels, as they 
are now constructed. An analysis of benefits and 
costs demonstrates that the costs of additional 
testing are less than the estimated savings in 
property and lives. Finally, the consumer of new 
tires is less likely than the retread consumer to 
shift his tire purchase habits and has less oppor- 
tunity to do so. The NHTSA has carefully de- 
termined the technological and economic impact 
of Standard 119 on the new tire industry and 
found it to be practicable. 

The NHTSA totally disagrees with the RMA 
and Firestone in their final argument that safety- 
related defect notification offers adequate protec- 
tion to consumers without the addition of a safety 
standard. Firestone inaccurately equates the ef- 
fect of a standard with that of a notification 
campaign, claiming that in either case a manu- 
facturer must recall tires containing defects or 
face civil penalties. Issuance of a standard im- 
poses significantly greater responsibility on a 
manufacturer to assure himself in the exercise 
of due care that his product is safe before it is 
sold and subsequent use reveals a safety-related 
defect. 

Technical Consideration of Standard 119 

The Application section (S3.) raised several 
questions about the standard's relationship to 
Standard 109-type tires, experimental tires, and 
low speed and off-road vehicle tires. The stand- 



ard applies to new tires designed for highway 
use on non-passenger-car motor vehicles. The 
present language makes clear that tires which do 
not meet these criteria are not subject to the 
standard, including those tires subject to Stand- 
ard 109. The tire manufacturer himself must 
determine whether his tires, restricted or not to 
speeds under 35 mi/h, or used on slow-moving 
vehicles on or off the highway, were designed by 
him for highway use. As an example, Dunlop 
cited moto-cross tires which use the public high- 
way "during the course of competitions." With- 
out evidence to the contrary, however, the 
NHTSA assumes that these tires are used to get 
to and from the competition over the public 
liighways. In answer to a related request for 
interpretation by Bridgestone, it is the designed 
and intended use of the tire (as realistically 
anticipated by the manufacturer) that matters, 
not a simple marking such as "Not For Highway 
Use" on the tire sidewall. In the case of "experi- 
mental" or "survey" tires the tires are designed 
for highway test purposes and are subject to the 
standard. 

The definition of light truck tire has been re- 
vised in response to comments from the RMA 
and the Japan Automobile Tire Manufacturers 
Association. They cited a number of light truck 
tires which may or may not share a common size 
designation or dimensions with passenger tires, 
but still require special test values because of 
their heavy-service construction. 

Standard 119 does not include the voluminous 
"tire tables" of tire size designation, maximum 
loads and inflation pressures, and dimensions re- 
quested by the domestic tire industry. An ex- 
planation of this approach accompanied issuance 
of the rule (38 F.R. 31299, November 13, 1973). 
While the RMA and Goodyear have restated 
their earlier position that product standardiza- 
tion can only be assured by Government publi- 
cation of industry association tables, they did 
not respond to the extensive justification made 
with the rule. The NHTSA concludes that its 
determination is sound. 

Nearly all tire manufacturers commented on 
Standard 119's labeling provisions and the 
amount of leadtime necessary to implement them. 
To resolve the most pressing problems, the 
NHTSA has already issued notices that postpone 



PART 571; S 119— PRE 9 



E«F*ctlve: March 1, 1975 



the effective date of the standard 6 months and 
propose a lettering size and depth, use of the 
DOT symbol prior to the standard's effective 
date, and clarification of the treadwear indicator 
requirement. (39 F.R. 4087, February 1, 1974, 
39 F.R. 3967, January 31, 1974). All other pe- 
titions which concern the labeling provisions are 
treated in this response. 

The RMA and the European Tyre and Rim 
Technical Organization (ETRTO) requested 
changes in paragraph S6.5(d) ("Tire marking"), 
several of which are adopted in this amendment. 
The word "corresponding" is inserted before 
"inflation pressure"' to accommodate tires whose 
maximum load rating is not at maximum infla- 
tion. Punctuation is removed from the legend 
that appears on the tire to simplify stamping. 
The example is revised to make clear that "TIRE 
RATED FOR SINGLE AND DUAL LOAD" 
and "TIRE RATED ONLY FOR SINGLE 
LOAD" do not appear on the tire sidewall. 
ETRTO suggested that a title appear on the tire 
to qualify the information provided, but the 
NHTSA has concluded that the information 
alone is more helpful to the unknowledgeable 
user, and that a knowledgeable user would refer 
to the tire tables for exact information before 
changing tire inflation pressure. 

Paragraph S6.5(e) on speed restricted tires 
has been clarified to limit the requirement to 
tires restricted to 55 mi/h or less. S6.5(f) re- 
mains unchanged, because the National Traffic 
and Motor Vehicle Safety Act of 1966 requires 
that the actual number of plies and ply compo- 
sition appear on the tire sidewall. The words 
"tube type" appear on tires under 86.5 (g) be- 
cause many consumers are unaware of the sig- 
nificant distinctions between tube type and 
tubeless tires. Dunlop's request that treadwear 
indicators be required on tires that are regrooved 
is beyond the authority under which Standard 
119, applying only to new tires, was issued. 

Paragraph S6.5(]') calls for a single letter to 
appear on the tire to indicate categories of 
strength within the size designation, for user 
information and test purposes. As the ETRTO 
pointed out, a requirement for any additional 
wording such as "load range" could confuse in- 
ternational standardization efforts. Manufactur- 



ers are, of course, entitled to add labeling 
information as long as tlie required information 
appears in the required format on the tire. 

The maximum load rating provision in S6.6 
requires tires of a particular size to have a maxi- 
mum load rating at least as great as the lowest 
rating published for that size. In this way the 
publications do not mislead a consumer who as- 
sumes that a particular tire size must have only 
the load ratings listed. The RMA advocated 
that more particular load rating information be 
supplied to aid in actual tire selection. Refer- 
ence to any factors other than tire size, however, 
would detract fi-om the desired concept that, for 
one tire size, there is one lowest maximum load 
rating, and that load rating is published. 

Two substantial requests were raised with re- 
gard to the endurance requirement. Uniroyal 
petitioned for a reduction in the duration of the 
three test phases to 4 hours each. Tlie NHTSA 
is considering that submission but must deny ac- 
tion on it at this time because an independent 
evaluation of the procedures lias not yet been 
conducted, and because there has not been notice 
or opportunity to comment on the proposal by 
all interested persons. 

The RMA petitioned for 34-hour endurance 
testing of all tires subject to the high speed test 
(S6.3) on the grounds that the 47- hour speed/ 
endurance test would be redundant. The NHTSA 
agrees and has revised Table III accordingly. 

The ETRTO proposed new test values for 
some motorcycle tires, but the request was un- 
clear as to the meaning of the 62 mi/h criterion 
and the unsupported request cannot be granted. 
If, in the future, the ETRTO petitions for rule- 
making to revise the table, an explanation of the 
criterion and a justification for the test values 
would permit an informed decision. 

Comments to the strength test questioned 
plunger size and energy values, the computation 
procedures, and the appropriateness of the test 
to mobile home, special trailer, wide base, and 
radial tires. 

The RMA argued that the limited service of 
mosc mobile home and special trailer tires could 
not justify the increased cost necessary to up- 
grade the strength of the tires to meet the re- 
quirement. The NHTSA has consistently treated 



PART 571; S 119— PRE 10 



Effective: March 1, 1975 



mobile homes and other trailers as full-fledged 
motor vehicles and ai^plied applicable standards 
rigorously to reduce the number of crashes in 
which mobile homes are involved, as indicated 
by BMCS statistics. The RMA request is denied 
to ensure that equally-rated tires on towed and 
towing vehicles will, in fact, meet equal minimum 
strength requirements. 

The RMA and ETRTO generally advocated 
larger plungers or reduced energy values for 
tires and the ETRTO petitioned for the exclu- 
sion of radial tires from the strength test. The 
NHTSA has determined that the established 
values and plunger sizes, drawn from industry 
experience, adequately measure tire strength. 
Any future petitions for rulemaking to change 
these values should be accompanied by detailed 
supporting data, as was submitted by Uniroyal 
in its petition for reconsideration. 

Comments again requested that a plunger 
which contacts the rim be considered to have 
established an energy value which meets the 
strength requirement. The NHTSA reiterates 
its position that the standard's present energy 
values measure the strength of a well-constructed 
non-passenger car tire before the tire breaks or 
the plunger contacts the rim. Specific test values 
may be revised based on future test experience, 
but revision of the calculation procedures used 
for all tires is not justified. The request for 
three plunger applications in the case of 12-in. 
or smaller diameter tires has been granted. 

Michelin and the ETRTO have inquired as to 
the NHTSA's position with regard to tubeless 
tires above load range J. Such tires, when 
marketed in the United States, are subject to this 
standard, and the NHTSA would like the benefit 
of detailed description of, and test experience 
with, these tires before it establishes test require- 
ments. It is requested that support for ETRTO 
or Michelin values be submitted to the NHTSA 
Tire Division. 

The high speed performance requirement was 
adopted to test different tire characteristics from 
those tested under the endurance performance 
requirement. The test is run only on non-speed- 
restricted tires in the lighter load ranges because, 



for tires of heavier construction, the endurance 
test alone develops temperatures which evaluate 
all the characteristics satisfactorily. The RMA 
and several manufacturers have pointed out that 
the endurance test can serve this purpose for 
large tires even in the lighter ranges, and the 
NHTSA, therefore, restricts the high speed re- 
quirements to motorcycle tires and to non-speed- 
restricted tires of 14.5-in nominal rim diameter 
or less marked Load Range A, B, C, or D. Light 
truck tires and other tires which are l-l.S-in and 
smaller remain subject to the high speed require- 
ments because the NHTSA has determined that 
the high speed test measures different values than 
the endurance test in these smaller sizes. 

The definition of tire failure is closely related 
to the endurance and high speed performance 
tests. The RMA and several tire manufacturers 
requested re-definitions of se\"eral terms and re- 
vision of the tire cooling procedures related to 
tire failure. The NHTSA has established Docket 
71-10, New pneumatic tires, revised j>erformance 
requirements, to treat the re-definition of tire 
failure, and will respond to these issues in a 
notice to that docket. 

Interested persons should remember that, in 
addition to the amendments set forth below, the 
NHTSA has already amended the effective date 
of the Standard to March 1, 1975, and has pro- 
posed amendments to the lettering, DOT certifi- 
cation, and treadwear provisions which will be 
acted on when comments have been considered. 

In consideration of the foregoing, amendments 
are made to Parts 571 and 574 of Title 49, Code 
of Federal Regulations. . . . 

Effective date : March 1, 1975. 

(Sees. 103, 112, 113, 114, 119, 201, Pub. L. 89- 
563, 80 Stat. 718, 15 U.S.C. 1392, 1401, 1402, 1403, 
1407, 1421; delegation of authority at 49 CFR 
1.51.) 

Issued on February 7, 1974. 

James B. Gregory 
Administrator 

39 F.R. 5190 
February 11, 1974 



PART 571; S 119— PRE 11-12 



i 



Effectivo: March 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 119 
New Pneumatic Tires for Vehicles Other Than Passenger Cars 
(Docket No. 71-18; Notice 7) 



This notice amends Standard No. 119, New 
pneumatic tires for vehicles other than passenger 
cars, 49 CFR 571.119, to specify lettering sizes 
and modified treadwear indicator requirements 
for tires. In addition, it amends Part 574, Tire 
Identification, 49 CFR 574, to permit the labeling 
of certain tires with the symbol DOT prior to 
the effective date of the standard. This notice 
also responds to petitions for reconsideration of 
Standard 119's effective date by maintaining the 
present date of March 1, 1975. 

To avoid a costly production shutdown on the 
effective date to engrave tire molds with the 
DOT compliance symbol required by the stand- 
ard, the National Highway Traffic Safety Ad- 
ministration (NHTSA) proposed a modification 
of the Part 574 prohibition on the symbol's use 
prior to the effective date (39 F.R. 3967, Jan- 
uary 31, 1974). The Rubber Manufacturers 
Association and five tire manufacturers agreed 
that the DOT should be engraved on tire molds 
prior to the effective date, but objected to the 
expense of covering the DOT with a label stating 
that "no Federal motor vehicle safety standard 
applies to this tire," when the DOT appears on 
tires which (presumably) satisfy Standard 119 
requirements. Firestone pointed out that the 
large label size could obscure other label infor- 
mation. Goodrich noted that, as proposed, the 
DOT could be molded on tires which met no 
standard and could mislead a user if the label 
fell off. 

The NHTSA will not permit the appearance 
of the DOT compliance symbol on any item of 
motor vehicle equipment to which no standard 
is applicable. The terms "applicability" and 
"applies" have only one meaning for Federal 
motor vehicle safety standards: that the vehicle 



or equipment concerned is subject to a safety 
standard. To permit use of the DOT sjTnbol on 
vehicles or items of motor vehicle equipment to 
which no standard applies would confuse the 
meaning of the symbol and the concept of com- 
pliance. 

In response to Firestone and Goodrich, the 
NHTSA has modified the lettering size on the 
label and limited use of the DOT symbol to tires 
for which a standard has been issued. With the 
small lettering size, the rubber labels used on 
retread tires can be applied over the DOT symbol 
in fulfillment of the requirement. Another 
method which manufacturers did not mention 
but which would be permissible is the removal 
of the DOT at the same time imperfections are 
buffed oft' the tire. 

All comments on the proposal objected to the 
specific location requirements for treadwear in- 
dicators based on the concept of even tread wear 
across the tread width. Goodyear demonstrated 
in a meeting with the NHTSA Tire Division on 
February 13, 1974, and detailed in its submission 
to the Docket, the difficulty in equating ideal tire 
wear with actual road experience. They recom- 
mended the simpler concept that a tire has worn 
out when any major tread groove has only %2 ^^ 
tread remaining. The NHTSA has concluded 
that treadwear indicators must be placed at the 
discretion of the manufacturer to give a person 
inspecting the tire visual indication of whether 
the tire has worn to a certain tread depth. Ac- 
cordingly, the lateral location requirements for 
treadwear indicators have been deleted from the 
standard. 

There was no discussion of the lettering size 
and depth proposal, and these proposals are 
adopted as proposed. 



PART 571; S 119— PRE 13 



Effective: March 1, 1975 



The comments requested reconsideration of the 
standard's March 1, 1975, effective date (pub- 
lished February 1, 1974, 39 F.R. 4087), asserting 
the need for 18 months of lead time following 
publication of this notice to engrave tire molds 
as required by the standard. The NHTSA has 
found that 11 months is sufficient lead time to 
accomplish these changes, and accordingly these 
petitions are denied. 

To correct an inadvertent omission in the 
amendment of Standard No. 119 in response to 
petitions for reconsideration (39 F.R. 5190, Feb- 
ruary 11, 1974), superscripts are added to Table 
III entries for "All other, A, B, C, D range 
tires". 

In consideration of the foregoing, Parts 571 
and 574 of Title 49, Code of Federal Regulations, 
are amended. . . . 



Effective date: Standard No. 119 amendments: 
March 1, 1975. Part 574 amendment: April 3, 
1974. Because the Part 574 amendment creates 
no additional burden, and because modification 
of tire molds must begin immediately, it is found 
for good cause shown that an effective date less 
than 180 days after issuance is in the public 
interest. 

(Sees. 103, 112, 119, 201, Pub. L. 89-563, 80 
Stat. 718 ; 15 U.S.C. 1392, 1401, 1407, 1421 ; dele- 
gation of authority at 49 CFR 1.51.) 

Issued on March 28, 1974. 

James B. Gregory 
Administrator 

39 F.R. 12104 
April 3, 1974 



PART 571; S 119— PRE 14 



{ 



Effective: March I, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 119 

New Pneumatic Tires for Vehicles Other Than Passenger Cars 
(Docket No. 74-25; Notice 2) 



This notice amends the definition of "test rim" 
in 49 CFR 571.109 (Motor Vehicle Safety Stand- 
ard No. 109) and modifies related provisions of 
that section and § 571.110 (Motor Vehicle Safety 
Standard No. 110). A conforming amendment 
is made to similar i)ro\'isions in § 571.119 (Motor 
Vehicle Safety Standard No. 119). The notice 
of proposed rulemakinfi on which this amend- 
ment is based was publisiied on July 10, 1974 
(39 F.R. 25329). 

The definition of "test rim" has previous to 
this amendment referenced the 1967 and earlier 
editions of publications of various foreign and 
domestic tire and rim associations as the source 
for determining rim specifications and appro- 
priate tire/rim matching information for testing 
tires to the requirements of Motor A^ehicle Safety 
Standard No. 109, and for equipping passenger 
oars pursuant to Motor Vehicle Safety Standard 
No. 110. The Rubber Manufacturers' Associa- 
tion i^etitioned that this reference be changed 
because the publications have become outdated 
in terms of the rim information they provide. 
This amendment, whicli adojjts the proposed rule 
of July 10, 1974, in essentially the form pro- 
posed, deletes the references to tlie 1967 and 
earlier publications and substitutes for them the 
publications of the various associations current 
at the time of tire manufacture. 

Under the amendment, a "test rim" will be any 
rim listed for use with a tire size designation in 
any of the current publications of the various 
foreign and domestic tire and rim associations. 
The listing will apply to all tires that fit the 
description (by tire size designation, use cate- 
gory, etc.) unless the publication itself or a sepa- 
rately published manufacturer's document states 
otherwise. A manufacturer wishing to except 



any tire manufactured by him froin any listing 
would be expected to request the association to 
publish the exception in its publication. If it 
does not, the manufacturer must himself publisli 
the exception in his own listing, which he must, 
distribute to his dealers, this agency, and to any 
member of the public on request. The language 
of the proposal is clarified, and a conforming 
amendment made to Standard No. 119 to show 
that an exception must be published in each 
association publication listing the tire and rim 
combination. The amendment further specifies 
that a "listing" of a rim must contain dimen- 
sional specifications, including diagrams, for the 
rim. This is necessary to provide for uniformity 
of rim dimensions and reflects the i)resent prac- 
tice of association publications of publishing 
such dimensional specifications. However, di- 
mensional specifications or a diagram of a rim 
need not be included in manufacturers' separate 
listings if the specifications and diagram for the 
rim appear in each association publication where 
it is listed. 

By referencing the current publications, the' 
amendment ends the need for Appendix "A" of 
Standard No. 110, which lists tire/rim combina- 
tions approved for, use subsequent to the 1967 and 
earlier associations publications. The associa- 
tions and various manufacturers should ascertain 
that all tire/rim combinations presently listed in 
that Appendix are incorporated into at least one 
of their respective publications before the effec- 
ti\'e date of this amendment. Moreover, the 
addition of new tire/rim combinations subsequent 
to the effective date becomes the sole responsi- 
bility of the industry. Appendix "A" of Stand- 
ard No. 109, listing tire size designations, is not 
affected by this amendment. 



PART 571; S 119— PRE 15 



Eff*ctiv«: March 1, 1975 



An effect of the amended definition of test rim 
is to clarify this agency's [wsition that each tire 
must be able to pass each performance require- 
ment (except that for physical dimensions) of 
Standard No. 109 with any rim with which it is 
listed, regardless of rim width, unless that tire 
is specifically excepted from each listing where 
it appears. The requirements for physical di- 
mensions must be met only on a test rim of the 
width si)ecified for the tire size designation in 
Standard No. 109. A tire failing the require- 
ments on any test rim would be considered as 
having failed the requirements on all test rims. 
This continues existing NHTSA enforcement 
policy. 

One of the two comments received regarding 
the proposal objected to this aspec-^t of the amend- 
ment, arguing that some manufiioturers have 
traditionally certified conformity on the basis of 
test results using only the test rims of the speci- 
fied test rim width and that no safety problems 
had been encountered. The NHTSA believes, 
however, that, the interest of safety demands that 
manufacturers ensure that tires certified as con- 
forming to Standard No. 109 will conform to the 
standard's requirements on any rim which the 
manufacturer lists for use with the tire and with 
which the tire may consequently be used in serv- 
ice. This position has been reflected in the guide- 
lines for the additions of new tire/rim combina- 
tions to the Appendix of Standard No. 110, 



which have required that the manufacturer dem- 
onstrate conformity to Standard No. 109 on each 
newly requested rim. If a manufacturer doubts 
the ability of his tires to conform to the standard 
on certain recommended rims, he has the option 
of excepting his tii-es from being used with those 
rims. No other objections to the proposed rule 
were received. 

In light of the above, amendments are made 
to 49 CFR §§ 571.109, 571.110, and 571.119 .... 

E-ffective date: August. 5, 1975 for Standards 
No. 109 and 110; March 1, 1975, for Standard 
No. 119. The amendment to Standard No. 119 
is of a clarifying nature, and should be made 
effective with the existing effective date of that 
standard. The amendment does not require sub- 
stantial leadtime for conformity, and it is found 
for good cause shown that an effective date less 
than 180 days from publication is in the public 
interest. 

(Sees. 103, 119, 201. 202, Pub. L. 89-563, 80 
Stat. 718; 15 U.S.C. §§1392, 1407, 1421, 1422; 
delegation of authority at 49 CFR 1.51.) 



Issued on January 31, 1975. 



James B. Gregory 
Administrator 

40 F.R. 5529 
February 6, 1975 



PART 571; S 119— PRE 16 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 119 



New Pneumatic Tires for Vehicles Other Than Passenger Cars 
(Docket No. 71-18, Notice 10) 



This notice establishes a uniform tire testing 
temperature for the test requirements of the 
Uniform Tire Quality Grading regulation and 
the Federal motor vehicle safety standard for 
non-passenger-car tires. This amendment simpli- 
fies existing requirements by permitting various 
tire tests to be conducted at the same temperature. 

Eifeetive date : July 17, 1978. 

For further information contact : 

Arturo Casanova III, Crash Avoidance Divi- 
sion, Office of Vehicle Safety Standards, 
National Highway Traffic Safety Adminis- 
tration, 400 Seventh Street, S.W.. "Washing- 
ton, D.C. 20590 (202-426-1715). 

Supplementary information: The National 
Highway Traffic Safety Administration 
(NHTSA) proposed on March 3. 1977. to amend 
the ambient temperature conditions for tire test- 
ing contained in Standard No. 119, New Pneu- 
matic Tires for Vehicles Other Than Passenger 
Cars (49 CFR 571.119), and in Part 575, Uniform 
Tire Quality Grading (49 CFR 575.104) 
(UTQG). The purpose of this proposed amend- 
ment was to harmonize existing tire testing tem- 
peratures as requested by the Goodyear Tire and 
Rubber Company. The ambient temperatures 
were previously specified as follows : 

Standard No. 109 : "100±5° F." 

Standard No. 119 : "any temperature ... up to 
100° F." 

UTQG : "at 105° F." 

In the notice of proposed ndemaking. the 
agency proposed to amend Standard No. 119 and 
UTQG to reflect the tire temperature utilized in 
Standard No. 109 (100±5° F.). As an alterna- 
tive method of expressing the test temperature. 



the NHTSA proposed to amend the standards to 
specify "any temperature up to 95° F. 

Five comments were received in response to 
that proposal. All comments favored the pro- 
posed amendment that would have instituted a 
100±5° F. temperature. The Vehicle I^quipment 
Safety Commission did not take a position on 
this proposal. 

After consideration of the issues involved m 
the proposal and review of the comments, the 
agency has determined that the test temperature 
should be expressed as "any temperature up to 
95° F." Accordingly, Standard No. 119 and 
UTQG are amended to specify temperature test- 
ing at "any temperature up to 95° F." It is the 
NHTSA's opinion that the 95° F. test tempera- 
ture is in effect the same test temperature as 
would be achieved by using the 5-degree tolerance 
(100±5). 

The NHTSA has often stated in interpretations 
on similar issues that the use of tolerances in 
safety standards reflects a misunderstanding of 
the legal nature of the safety standards. Stand- 
ards are not instructions, but performance levels 
that vehicles or equipment are required by law to 
be capable of meeting. Any tolerance in this 
context would be meaningless and misleading, 
since it would merely have the effect of stating a 
performance level that tiie equipment nuist meet 
when tested by the govemment, but in a confus- 
ing manner. 

Recognizing that no measurement is perfectly 
precise, a manufacturer's tests should be designed 
to show, using tire testing temperature as an 
example, that his tires will comply with the re- 
(juirements at exactly 95° F. This may be done 
in at least two ways: (1) by using a test method 
tliat corresponds so closely to the require^l tem- 



PART 571; S 119— PRE 17 



perature that no significant differences could 
occur as a result of differences between the actual 
temperature and the specified one, or (2) hy 
determinino^ which side of the specified tempera- 
ture is adverse to the product tested, and beinj;; 
sure that the actual temperature of the test dif- 
fers from the specified one on the adverse side. 

The amendment of Standard No. 119 and 
UTQG to reflect the 95° F. temperature creates a 
different temperature phraseolojiy for those 
standards than exists in Standard No. 109 which 
still has the 100±5° F. temperature. As stated 
earlier, the NHTSA considers the Standard No. 
109 temperature tolerance to mean in actuality 
"any temperature up to 95° F." However, since 
modification of that standard was not proposed 
in the earlier notice, the agency does not amend 
it in this final rule. However, the agency intends 
to issue an interpretive amendment that will 
amend Standard No. 109 to adopt the alternative 
expression for tire temperature testing (any 
temperature up to 95° F.) unless objections are 
received. 

In accordance with Departmental policy en- 
couraging analysis of the impact of regulatory 
actions upon the public and private sectors, the 
agency has determined that tliis modification will 
result in no appreciable safety gains or losses. 



These amendments may result in slightly lower 
costs for tire temperature testing since all tem- 
peratures will be uniform. 

Since these amendments relieve restrictions and 
impose no additional burdens, it is found for 
good cause shown that an immediate effective 
date is in the public intei'est. 

In consideration of the foregoing, the following 
amendments are made in Parts 571 and 575 of 
Title 49, Code of Federal Regulations. . . . 

The program official and lawyer principally 
responsible for the development of this rulemak- 
ing document are Arturo Casanova and Roger 
Tilton, respectively. 

(Sees. 103, 112, 119. 201, 203, Pub. L. 89-563, 
JiO Stat. 718 (15 U.S.C. 1392, 1401, 1421, 1423); 
delegation of authority at 49 CFR 1.50.) 

Issued on Julv 12. 1978. 



Joan Claybrook 
Administrator 

43 F.R. 30541-30542 
July 27, 1978 



PART 571; S 119— PRE 18 



MOTOR VEHICLE SAFETY STANDARD NO. 119 
New Pneumatic Tires for Vehicles Other Than Passenger Cars 



51. Scope. This standard establishes per- 
formance and marking requirements for tires 
for use on multipurpose passenger vehicles, 
trucks, buses, trailers, and motorcycles. 

52. Purpose. The purpose of this standard is 
to provide safe operational performance levels 
for tires used on motor vehicles other than pas- 
senger cars, and to place sufficient information 
on the tires to permit their proper selection and 
use. 

53. Application. This standard applies to 
new pneumatic tires designed for highway use 
on multipurpose passenger vehicles, trucks, buses, 
trailers and motorcycles manufactured after 
1948. 

54. Definitions. All terms defined in the Act 
and the rules and standards issued under its 
authority are used as defined therein. 

"Light truck tire" means a tire designated by 
its manufacturer as primarily intended for use 
on lightweight trucks or multipurpose passenger 
vehicles. 

"Model rim assembly" means a test device that 
(a) includes a rim which conforms to the pub- 
lished dimensions of a commercially available 
rim, (b) includes an air valve assembly when 
used for testing tubeless tires or an innertube 
and flap (as required) when used for testing 
tube-type tires, and (c) undergoes no permanent 
rim deformation and allows no loss of air 
through the portion that it comprises of the 
tire-rim pressure chamber when a tire is properly 
mounted on the assembly and subjected to the 
requirements of this standard. 

55. Tire and rim matching information. 

S5.1 Each manufacturer of tires shall ensure 
that a listing of the rims that may be used with 
each tire that he produces is provided to the 
public. For purposes of this section, each rim 



listing shall include dimensional specifications 
and a diagram of the rim. However, a listing 
compiled in accordance with paragraph (a) of 
this section need not include dimensional speci- 
fications or a diagram of a rim if the rim's di- 
mensional specifications and diagram are con- 
tained in each listing published in accordance 
with paragraph (b). The listing shall be in one 
of the following forms: 

(a) Listed by manufacturer name or brand 
name in a document furnished to dealers of the 
manufacturer's tires, to any person upon request, 
and in duplicate to: Tire Division, National 
Highway Traffic Safety Administration, 400 
Seventh Street, S.W., Washington, D.C. 20590; 
or 

(b) Contained in publications, current at the 
date of the manufacture of tire or any later date, 
of at least one of the following organizations: 

The Tire and Rim Association. 

The European Tyre and Rim Technical 
Organisation. 

Japanese Industrial Standards. 

Deutsche Industrie Norm. 

The Society of Motor Manufacturers and 
Traders, Ltd. 

British Standards Institution. 

Scandinavian Tire and Rim Organisation. 

S5.2 Information contained in a publication 
specified in S5.1(b) which lists general cate- 
gories of tires and rims by size designation, type 
of construction, and/or intended use, shall be 
considered to be manufacturer's information 
pursuant to S5.1 for the listed tires, unless the 
publication itself or specific information pro- 
vided according to S5.1(a) indicates otherwise. 

S6. Requirements Each tire shall be capable 
of meeting any of the applicable requirements 
set forth below, when mounted on a model rim 



PART 571; S 119-1 



assembly corresponding to any rim designated 
by the tire manufacturer for use with the tire in 
accordance with S5. However, a particular tire 
need not meet further requirements after having 
been subjected to and met the endurance test 
(S6.1), strength test (S6.2), or high speed per- 
formance test (S6.3). 

56.1 Endurance. 

56.1.1 Prior to testing in accordance with the 
procedures of S7.2, a tire shall exhibit no visual 
evidence of tread, sidewall, ply, cord, innerliner, 
or bead separation, chunking, broken cords, 
cracking, or open splices. 

56.1.2 When tested in accordance with the 
procedures of S7.2: 

(a) There shall be no visual evidence of tread, 
sidewall, ply, cord, innerliner, or bead separa- 
tion, chunking, broken cords, cracking, or open 
sphces. 

(b) The tire pressure at the end of the test 
shall be not less than the initial pressure speci- 
fied in S7.2(a). 

56.2 Strength. When tested in accordance 
with the procedures of S7.3 a tire's average 
breaking energy value shall be not less than the 
value specified in Table II for that tire's size 
and load range. 



56.3 High speed performance. When tested 
in accordance with the procedures of S7.4, a tire 
shall meet the requirements set forth in S6.1.1 
and S6. 1.2(a) and (b). However, this require- 
ment applies only to motorcycle tires and to non- 
speed-restricted tires of 14.5-in nominal rim 
diameter or less marked load range A, B, C, or 
D. 

56.4 Treadwear indicators. Except as speci- 
fied below, each tire shall have at least six tread- 
wear indicators spaced approximately equally 
around the circumference of the tire that enable 
a person inspecting the tire to determine visually 

Table I— Strength Test Plunger Diameter 

Tire type: Plunger Diameter 

(inches) 

Light truck % 

Motorcycle %e 

Tires for 12-inch or smaller rims, 

except motorcycle % 

Tires other than the above types; 

Tubeless: 

17.5-inch or smaller rims % 

Larger than 17.5-inch rims: 

Load range F or less V/t 

Load range over F 1 V2 

Tube type: 

Load range F or less 1 'A 

Load range over F 1 '/2 



Table II— Minimum Static Breaking Energy (Inch-Pounds) 



Plunger 
diameter 



%6 Inch 



% Inch 



IV4 Inch 



IV2 Inch 



Tire 
characteristic 



Motorcycle 



All 12-inch 
or smaller 
rim size 



-Light truck Tube 
-17.5 inch or type 
smaller Rim 
Tubeless 



Tubeless 



Tube 
type 



Tubeless 



A 
B 
C 
D 
E 
F 
G 
H 
J 
L 
M 
N 



Load range 



150 


600 


300 


1200 


400 


1800 




2400 




3000 




3600 



2000 





2600 





3200 


6800 


4550 


7900 


5100 


12500 


5700 


15800 


6300 





6800 






5100 





6500 





8600 





12500 








20200 





23000 




25000 




27000 





28500 





30000 



1500 
18500 
19500 



For rayon cord tires, applicable energy values are 60 percent of those in table. 



PART 571; S 119-2 



Table III— Endurance Test Schedule 



Description 




Load range 


Test wheel 
speed 
(rpm) 


Test load: Percent of 
maximum load rating 


Total test 
revolutions 
(thousands) 




I 
7hrs. 


II 

16 hrs. 


III 

24 hrs. 




Speed-Restricted service 
55 m.p.h. 




All 

C, D 


125 

150 

100 
75 
250 
250 
200 
200 
175 
150 


66 
75 

66 
66 
'100 
'75 
70 
66 
66 
66 


84 
97 

84 
84 

no8 

297 
88 
84 
84 
84 


101 
114 

101 
101 
117 
114 
106 
101 
101 
101 


352.5 


50m.p.h. _ . 


) 


423.0 




) 


E, F, G, H, 
J,L 


282.0 


35 m.p.h. . _ 


All 


211.5 


Motorcycle 
All others 


- 


All 

A, B, C, D 

E 

F . 

G 

H, J, L, N 


510.0 
510.0 




) 
) 
) 

) 


564.0 
564.0 
493.5 
423.0 



' 4 hours for tire sizes subject to high speed requirements (S6.3) 
2 6 hours for tire sizes subject to high speed requirements (S6.3) 

whether the tire has worn to a tread depth of 
one-sixteenth of an inch. Tires with 12-inch or 
smaller rim diameter shall have at least three 
such treadwear indicators. Motorcycle tires 
shall have at least three such indicators which 
permit visual determination that the tire has 
worn to a tread depth of one-thirty-second of an 
inch. 

S6.5 Tire marking. Except as specified below, 
each tire shall be marked on each sidewall with 
the information specified in paragraphs (a) 
through (j) of this section. The markings shall 
be placed between the maximum section width 
(exclusive of sidewall decoration or curb ribs) 
and the bead on at least one sidewall. The mark- 
ing shall be in letters and numerals not less than 
0.078 inches high and raised above or sunk below 
the tire surface not less than 0.015 inches, except 
that the marking depth shall be not less than 
0.010 inches in the case of motorcycle tires. The 
tire identification and the DOT symbol labeling 
shall comply with Part 574 of this chapter. 
Markings may appear on only one sidewall and 
the entire sidewall area may be used in the case 
of motorcycle tires and recreational, boat bag- 
gage, and special trailer tires. 

(a) The symbol DOT, which shall constitute 
a certification that the tire conforms to ap- 



plicable Federal motor vehicle safety standards. 
This symbol may be marked on only one side- 
wall. 

(b) The tire identification number required 
by Part 574 of this chapter. This number may 
be marked on only one sidewall. 

(c) The tire size designation as listed in the 
documents and publications designated in S5.1. 

(d) The maximum load rating and corre- 
sponding inflation pressure of the tire, shown as 
follows: 

(mark on tires rated for single and dual load) 

Max load single lbs at psi cold 

Max load dual lbs at psi cold 

(Mark on tires rated only for single load) 

Max load lbs at psi cold 

(e) The speed restriction of the tire, if 55 
mi/h or less, shown as follows: 

Max speed mph 

(f) The actual number of plies and the com- 
position of the ply cord material in the sidewall, 
and, if different, in the tread area. 

(g) The words "tubeless" or "tube type" as 
applicable. 

(h) The word "regroovable" if the tire is de- 
signed for regrooving. 
(i) The word "radial" if a radial tire, 
(j) The letter designating the tire load range. 



PART 571; S 119-3 



S6.6 Maximum load rating. If the maximum 
load rating for a particular tire size is shown in 
one or more of the publications described in 
S5.1(b), each tire of that size designation shall 
have a maximum load rating that is not less 
than the published maximum load rating, or if 
there are differing published ratings for the 
same tire size designation, not less than the low- 
est published maximum load rating for the size 
designation. 

S7. Test procedures. 

57.1 General conditions. 

57.1.1 The tests are performed using an ap- 
propriate new tube, tube valve and flap assembly 
(as required) that allows no loss of air for test- 
ing of tube-type tires under S7.2, S7.3, and S7.4, 
and tubeless tires under S7.3. 

57.1.2 The tire must be capable of meeting 
the requirements of S7.2 and S7.4 when condi- 
tioned at any ambient temperature up to 100° F. 
for 3 hours before the test is conducted, and 
with an ambient temperature maintained at any 
level up to 100° F. during all phases of testing. 
The tire must be capable of meeting the require- 
ments of S7.3 when conditioned at any ambient 
temperature up to 70° F. for 3 hours before the 
test is conducted. 

57.2 Endurance, (a) Mount the tire on a 
model rim assembly and inflate it to the inflation 
pressure corresponding to the maximum load 
rating marked on the tire. Use single maximum 
load value when the tire is marked with both 
single and dual maximum load. 

(b) After conditioning the tire-rim assembly 
in accordance with S7.1.2, adjust the tire pres- 
sure to that specified in (a) immediately before 
mounting the tire rim assembly. 

(c) Mount the tire-rim assembly on an axle 
and press it against a flat-faced steel test wheel 
that is 67.23 inches in diameter and at least as 
wide as the tread of the tire. 

(d) Apply the test load and rotate the test 
wheel as indicated in Table III for the type of 
tire tested conducting each successive phase of 
the test without interruption. 



(e) Immediately after running the tire the 
required time, measure the tire inflation pressure. 
Remove the tire from the model rim assembly, 
and inspect the tire. 

S7.3 Strength, (a) Mount the tire on a model 
rim assembly and inflate it to the pressure cor- 
responding to the maximum load, or maximum 
dual load where there is both a single and dual 
load marked on the tire. If the tire is tubeless, 
a tube may be inserted to prevent loss of air 
during the test in the event of puncture. 

(b) After conditioning the tire-rim assembly 
in accordance with S7.1.2, adjust the tire pres- 
sure to that specified in (a). 

(c) Force a cylindrical steel plunger, with a 
hemispherical end and of the diameter specified 
in Table I for the tire size, perpendicularly into 
a raised tread element as near as possible to the 
centerline of the tread, at a rate of 2 inches per 
minute, until the tire breaks or the plunger is 
stopped by the rim. 

(d) Record the force and the distance of 
penetration just before the tire breaks, or if it 
fails to break, just before the plunger is stopped 
by the rim. 

(e) Repeat the plunger application at 72° 
intervals around the circumference of the tire, 
until five measurements are made. However, in 
the case of tires of 12-in rim diameter or less, 
repeat the plunger application at 120° intervals 
around the circumference of the tire, until three 
measurements are made. 



(f) Compute the breaking energy 
test point by the following formula: 



for each 



W = 



FP 



where 
W = Breaking energy 
F = Force in pounds, and 
P = Penetration in inches. 

(g) Determine the average breaking energy 
value for the tire by computing the average of 
the values obtained in accordance with (f). 



PART 571; S 119-4 



S7.4 High speed performance. 

(a) Perform steps (a) through (c) of S7.2. 

(b) Apply a force of 88 percent of the maxi- 
mum load rating marked on the tire (use single 
maximum load value when the tire is marked 
with both single and dual maximum loads), and 
rotate the test wheel at 250 rpm for 2 hours. 

(c) Remove the load, allow the tire to cool to 
100° F., and then adjust the pressure to that 
marked on the tire for single tire use. 



(d) Reapply the same load, and without in- 
terruption or readjustment of inflation pressure, 
rotate the test wheel at 375 rpm for 30 minutes, 
then at 400 rpm for 30 minutes, and then at 
425 rpm for 30 minutes. 

(e) Immediately after running the tire the 
required time, measure the tire inflation pressure. 
Remove the tire from the model rim assembly, 
and inspect the tire. 

38 F.R. 31299 
November 13, 1973 



PART 571; S 119-5 



i 



i 



I 



Effective: August 1, 1976 

September 1, 1976 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 120 
Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars 

(Docket No. 71-19; Notice 3) 



This notice establishes a now Federal Motor 
Vehicle Safety Standard No. liiO, Tire selection 
and rims for motor vehicles other than passenger 
ears, 49 CFR 571.120. and amends 49 CFR Part 
.567, Certif ration. Tlie new standard specifies 
tire and rim selection requirements for multi- 
purpose passen<rer vehicles (MPV's), trucks, 
buses, trailers, and motorcycles, and marking re- 
quirements for rims for use on these vehicles. It 
also adds tire and rim matchinir information to 
the items required to appear on such vehicles' 
certification labels. The amendment to Part .567 
makes that regulation consistent with tiie neAV 
standard. The notice is based on proposals 
which were published August 3, 1971 (36 F.R. 
14273) and June 3. 1974 (39 F.R. 19305). 

The standard requires new veiiicles (other than 
passenger cars, which are the subject of Standard 
No. 110) to 1)6 equipped with tires that comply 
with either Standard Xo. 109. Xeir Pneumatic 
Tires — Passenger Cars, oi- Standard Xo. 119, 
A^ew Pneumatic Tires for Vehicles Other Than 
Passenger Cars. Tlie tires nnist be fitted to rims 
which have been designated by the tire manu- 
facturei-, in accordance with S4.4 of Standard 
Xo. 109 or S5.1 of Standard Xo. 119. as suitable 
for use with those tires. The designations are 
made by listing the tire-rim matching informa- 
tion in one of seven industry-maintained publi- 
cations or i)y furnishing tliis information to 
dealers of the manufacturer's tires, to any person 
upon request, and to the XHTSA. 

Each axle must be equipped with tiies the 
sum of whose load ratings is not less than that 
axle system's Gross Axle "Weight Rating 
(GAWR). In certain situations, discussed be- 
low, a vehicle may be equipped with used tires 
of adequate load rating that were f)riginally 



manufactured to comply with Standard Xo. 119. 
Ade<iuacy is determined as follows: the sum of 
the maxiimim load ratings of the tires must be 
equal to or greater than the GAAVR which is 
specified on the Pait 567 certification label, with 
an exception discussed below. If the certification 
label lists more than one GAWR-tire (•ond)ina- 
tion for the axle, the sum of tiie tii-es' maximum 
load ratings must meet or exceed the GAWR 
that corresponds to the tires" size designation. 
If more than one combination is listed, but the 
size designation of the actmil tires on the ve- 
hicle is not among those listed, then the sum of 
the load ratings must simply meet or exceed the 
lowest GAWR which does appear. 

Rims must be marked with five items of infor- 
mation: the size designation (and, in the case of 
multipiece rims, the type designation), an indi- 
cation of the source of the rim's nominal dimen- 
sions, and the DOT symbol must appear on the 
weather side, while identification of the manu- 
facturei- and date of manufacture may appear 
at any place on the rim's surface. The standard 
does not explicitly require that a rim conform 
to its published dimensions. If a rim's deviation 
from these nominal dimensions is so great that 
a safety hazard is presented, however, the defect 
notification and remedy provisions of the X'^a- 
tional Tiaffic and Motor Vehicle Safety Act of 
1966, as amended, provide authority to deal with 
the hazard. 

To reduce the possibility of confusion and to 
minimize the numbei' of characters stamped on 
the I'im. the standard establishes a set of code 
letters tr> indicate the source of the rim's nominal 
dimensions. "T", "E", "J". "D", "M", "B", and 
".S" indicate the industry publications listed in 
Standards Xos. 109 and 119, while "X""" indicates 



PART 571; S 120— PRE 1 



Effective: August 1, 1976 

September 1, 1976 



an independent listing with tire dealers and the 
NHTSA. The proposed requirement that the 
marking indicate the date of tiie publication has 
not been adopted because it does not appear 
necessary. The standard does not require manu- 
facturers to be identified with a code number 
assigned by the NHTSA, because no action has 
been taken on tlie proposal published in the 
Federal Register on June 7, 1973 (38 F.R. 
14968). The rim manufacturer is free to use his 
name, trademark, or a symbol of his choice. 
Because a rim's maximum load rating may be 
limited by its disc, this standard does not require 
that the maximum load rating be marked. The 
rim's maximum inflation pressure, while not af- 
fected by the choice of disc, is potentially mis- 
leading without additional marking of the disc. 
These rim markings are being considered in con- 
junction with further NHTSA rulemaking ac- 
tivity concerning wheels. 

Several commenters objected to the proposed 
requirement of a tire-rim infonnation label, 
separate from and adjacent to the certification 
label required by Part 567. Upon consideration 
of these comments, the NHTSA agrees that a 
separate placard is unnecessary. GVWR and 
GAWR are already required to appear on the 
certification label. If the required manufacturer 
exercises his option of listing more than one 
GVIVRGAWR combination, he is already re- 
quired to indicate the proper tire size designa- 
tions after each weight rating. Standard No. 
120 further requires, for vehicles other than pas- 
senger cars, the following information to appear 
after each weight rating and tire size designation 
listed on the certification label : rim size desig- 
nation, cold inflation pressure for the tires, and 
speed restriction (if any) for the tires. This 
information is now required to appear even when 
only one GVWR-GAWR combination is listed. 
The Part 567 label is thus expanded to include 
the information that would have appeared on 
the separate label described in S5.4 of the pro- 
posed Standard No. 120. 

Many commenters pointed to the large number 
of possible axle-tire-rim combinations and sug- 
gested that the information label would be too 
large and confusing. Some discussed the vehicle 



manufacturer's difficulty in ensuring that the re- 
quired information appear, given the common 
practice of changing tires and rims after a new 
vehicle has been shipped to a dealer. These 
commenters appear to have misunderstood the 
various proposed and existing requirements. 
Part 567 does not, in its prior form or as 
amended today, require a listing for more than 
one GVWR-GAWR-tire combination. Further, 
while S5.1.2 of Standard No. 120 requires the 
tires with which a new vehicle is equipped to be 
of adequate load rating for the GAWR, and 
while S5.3 requires an indication of tires ade- 
quate for the GAWR, there is no requirement 
that the actual tires be listed on the certification 
label. The tire information on that label is in- 
tended as a guide which tells the user what re- 
placement tires, as a minimum, are appropriate, 
for the listed GAWR and what rims are appro- 
priate for those tires. 

Guerdon Industries, Inc., objected to the re- 
quirement that vehicles be restricted to the load 
limits molded on tire sidewalls. The pointed 
to the mobile home industry's practice of load- 
ing tires to 150 percent of their load ratings, and 
argued that this practice should be permitted to 
continue. Examination of data compiled by the 
Bureau of Motor Carrier Safety, however, shows 
that from 1969 to 1972 (the most recent years 
for which figures are available), tires accounted 
for 18.0 percent of reported mobile home acci- 
dents. The NHTSA therefore rejects the propo- 
sition that such overloading does not present a 
safety hazard. There is no exception to the 
requirement tliat all vehicles be equipped with 
tires of adequate load rating. 

Some commenters requested that tire overload- 
ing be permitted under restricted speed condi- 
tions. These commenters appear to have 
misunderstood the scope of the standard. Ve- 
hicles-in-use are regulated by the States and by 
the Bureau of Motor Carrier Safety. Standard 
No. 120 does not prohibit the overloading of 
tires in speed-restricted service, or otherwise 
regulate the use of tires or vehicles. The GVAVR 
and GAWR information on the certification 
label is based on unrestricted service. 



PART 571; S 120— PRE 2 



The formula described above for tire selection 
is subject to an exception for MPV's, trucks, 
buses, and trailers which are eijuipped witli pas- 
senjjer car tires. Tlie combined maximum load 
ratinfr of tiie passen<rer car tires on an axle must 
be equal to or jrreater than 110 percent of the 
axle's GAWR. Some comments suppoited this 
exception as it was proposed. Otlieis sufr.irested 
that passenger car tires be permitted on such 
vehicles without tlie 110% factor, while the RMA 
and others ar^rued tliat passen<rer car tires sliould 
not be permitted on trailers at all. The XHTSA 
rejects the argument that the 110% correction 
factor is unnecessary. Because non-passen<rer- 
car service on the average puts <rreater stresses 
on a tire (for example, trucks and trailers are 
driven at or near their maximum rated loads 
more often than passenjrer cars), a jriven load 
ratinfr for a Standard Xo. 100 tires does not have 
tlie same meaning as the identical load ratinjr 
for a Standard Xo. 119 tire. Conversely, the 
XHTSA has found no evidence that passenfrer 
car tires are inadequate for trailer service when 
the load correction factor is applied. The 110 
percent factor is therefore adopted as proposed. 

As proposed, the standard included an excep- 
tion to the requirement that new vehicles be 
equipped with new tires conformin<r to Standard 
Xo. 100 or 110. Used tires were to be ])ermitted 
on a truck, bus, or trailer (other than a mobile 
structui'e trailer) under the followinir conditions: 
the tires were orijrinally manufactui'ed to (X)m- 
l)ly with Standard Xo. 110; tliey were of ade- 
(juate load ratin<r; they were owned or leased by 
the purchaser; and they were installed on the 
new vehicle at its place of manufacture at the 
[lurchaser's re(iuest. Conunents on this exception 
were /.renerally favorable, althoufrh one mobile 
home manufacturer objected to the exclusion of 
mobile stnicture trailers. The exception was in- 
tended to acconunodate conunei'cial delivery 
practices in the truck, bus, and trailer indnstiv. 
While fleets which lease tires on a milean:e- 
contract basis or which install their own used 
tires (m new vehicles are in a <rood j)osition to 
Imow the condition of these tires, the mobile 
home purchaser has no knowledge of the history 
of used tires installed on his vehicle. The pro- 
posed exception to the new tire requirement is 
therefore not extended to include all mobile 



Effective: August 1, 1976 

September 1, 1976 

structure trailers. It is, however, extended to 
include those delivered to the purchaser by a 
motor carrier, because a motor carrier (who is 
subject to Bureau of Motor Carrier Safety regu- 
lations) can be expected to be more familiar with 
tire safety needs than a typical purchaser. To 
clarify the proposed language. " originally manu- 
factured to comply with Standard Xo. 110," the 
words ''as evidenced by the DOT .symbol" have 
been added to the text of the .standard. 

Several commenters pointed out that certain 
vehicles are designed for non-uniform side to 
side loading, and suggested that the proposed 
method of determining the necessary tire load 
rating from the CxAWR (dividing GAWR by 
the number of wheel positions on the axle) is 
inadequate for such vehicles. These commenters 
argued that tire load rating should be based on 
the maximum wheel load, rather than on the 
GAAVR. The standard issued today does not 
specify the maximum load rating to be exceeded 
by each tire on any given axle. Instead, it re- 
((uires the sum of those load ratings to meet or 
exceed the GAWR. The manufacturer of an 
a.syuunetrically designed vehicle can therefore 
equip an axle with tires of ditfering load ratings. 
The XHTSA agrees that each tire should be 
capable of carrying its maximum expected wheel 
load. At this time, however, the XHTSA con- 
siders its defect authority, combined with the 
new standard, adequate to ensure that vehicles 
are equipped with such tires. 

Definitions have been added to clarify the 
meaning of "rim base," ''rim size designation," 
''rim type designation," "rim diameter," "rim 
width," and "weather side." Definitions sug- 
gested for other terms have not been included in 
the standard because the meanings have been 
found to be widely understood or self evident. 

Many comments pointed out problems with a 
single effective date. For example, for marked 
rims to be available to vehicle manufacturers in 
time, and interval is neces,sary between the effec- 
tive dates for the rim marking requirement and 
the requirement that \'ehicles be e<iuipped with 
rims that comply with the standard. Similarly, 
to lequire all used tires, otherwise permitted by 
Sr».1.3 to have originally been manufactured to 



PART .Hi; S 120— PRE 3 



EfFeclive: August 1, 1976 

September 1, 1976 

comply with Standard No. 119 would, without a 
delay in the effective date, cause the waste of pie- 
Standard No. 119 tires of adequate load-carrying 
capacity. Accordingly, a staggered system of 
effective dates is established as set out below. 

In consideration of the foregoing. Chapter V 
of Title 49, Code of Federal Kegulations, is 
amended. . . . 

Effective dates: For the amendment to Part 
567: September 1, 1976. For Standard No. 120: 
August 1, 1976, for the rim marking require- 
ments (S5.2), and September 1, 1976, for the 



I'emaining requirements except as otherwise pro- 
vided in the standard. 

(Sees. 103, 112, 114, 119, 201, 202, Pub. L. 
89-563, 80 Stat. 718 (15 U.S.C. 1392, 1401, 1403, 
1407, 1421, 1422) ; delegation of authority at 49 
CFR 1.50.) 

Issued on January 19, 1976. 

James B. Gregorv- 
Administrator 

41 F.R. 3478 
January 23, 1976 



\ 



PART 571; S 120— PRE 4 



{ 



Effective: May 6, 1977 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 120 
Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars 

(Docket No. 71-19; Notice 4) 



This notice delays the effective dates of certain 
requirements of Standard No. 120, Tire Selec- 
tion and Rims for Motor Vehicles Other Than 
Passenger Cars, and of the conforming amend- 
ment to 49 CFR Part 567, Certification, that was 
issued along with the standard. Its purpose is 
to permit manufacturers to avoid the burden of 
preparation for compliance witli requirements 
that the NHTSA has determined should be 
amended. There is no delay, however, in the 
standard's basic tire and rim selection require- 
ments, which become effective September 1. 1976. 

Standard No. 120 (49 CFR §571.120) was 
issued on Januaiy 19, 1976 (41 FR 3478; Jan- 
uary 23, 1976; Notice 3). It specifies require- 
ments for tire and rim selection, rim marking, 
and the provision of tire and lim information 
on vehicle certification labels. Part 567, the 
certification regulation, was amended in the same 
Fedehal Registeh notice, to accommodate the 
additional labeling. 

Manufacturers are expected to begin prepara- 
tions for compliance with a standard at the time 
a final rulemaking notice is issued. Lead times 
are established in accordance with this expecta- 
tion, despite the possibility of future amend- 
ments. Fifteen petitions for reconsideration of 
Standard No. 120 have been received. From the 
petitions and other information available to this 
agency, the NHTSA has determined that certain 
provisions of the standard should be amended. 
However, the agency finds it impracticable to 
respond to the petitions by May 24, 1976, the 
date by which a response would be expected 
imder its policy regarding such responses (49 
CFR Part 553, Appendix). The agency plans 
to respond to the petitions not later than July 1, 
1976. Without a delay of certain effective dates, 
manufacturers would be forced to make prepara- 



tion for compliance with requirements that will, 
in all likelihood, be changed. 

Accordingly, this notice changes from Sep- 
tember 1, 1976. to September 1, 1977, the effective 
date of the requirement, found in S5.3, that cer- 
tain information appear on a vehicle's certifica- 
tion label. The effective date of the confonning 
amendment to Part 567, Certifcafion, is similarly 
changed to September 1, 1977. The effective 
date of S5.2, Iii?n Marking, is changed from 
August 1, 1976, to August 1, 1977. The date by 
which vehicles must be equipped with rims that 
are marked in accordance with the standard, 
wliich is presently specified in S5.1.1 as March 
1, 1977, is changed to September 1, 1979. The 
NHTSA is considering the possibility of elimi- 
nating this requirement entirely, to simplify the 
pliase-in of properly marked rims as they become 
available. 

Manufacturers should note that, apart from 
tlie cluuiged effective date for the requirement 
in S5.1.1 that vehicles be equipped with properly 
marked rims, there is no delay in the September 
1, 1976, effective date of the standard's basic re- 
(juirement, S5.1 (Tire and Rim Selection) . 

The symbol "DOT" is required by S5.2(c) to 
appear on every non-passenger-car rim manu- 
factured on or after the effective date of the rim 
marking requirements, as a certification by the 
manufacturer of the rim tliat it complies with 
all applicable Federal motor vehicle safety stand- 
ards. Several manufacturers have requested 
permission to begin stamping the symbol on rims 
tliat otherwise comply witli tlie standard, before 
that effective date. In the past, the NHTSA 
has in similar situations taken the position that 
such use of the DOT symbol to indicate "antici- 
patory compliance" would necessarily be a false 



PART 571; S 120— PRE 5 



Effecfive: May 6, 1977 



or misleading certification, because no standard 
would in fact be in effect at the time of its use. 

The agency has determined that a limited 
relaxation of this principle will not adversely 
affect its enforcement authority, yet will both 
foster early compliance with impending require- 
ments and ease manufacturer's difficulties in 
transition to new production procedures. Ac- 
cordingly, the NHTSA will not consider the use 
of the symbol "DOT" on an it^m of motor ve- 
hicle equipment that is not subject to any appli- 
cable and effective standard to be "false or 
misleading" if the following conditions are met : 
(i) there has, as of the date of manufacture of 
the item of equipment, been issued as a final rule 
a Federal motor vehicle safety standard to which 
the item of equipment would, but for that date's 
being earlier than the standard's effective date, 
be subject; and (ii) the item of equipment meets 
all requirements set out in the standard as most 
recently published before the date of manufac- 
ture of the equipment. The NHTSA will con- 
tinue to consider other, unauthorized uses of the 
symbol to be "false or misleading in a material 
respect" within the meaning of Section 108(a)- 
(1) (C) of the National Traffic and Motor Ve- 
hicle Safety Act of 1966, as amended (15 U.S.C. 
1398(a)(1)(C)). 



This interpretation will permit the requested 
stamping that is discussed above. It will not 
permit the restamping, requested by several man- 
ufacturers, of previously manufactured rims 
that are in stock. These latter requests, how- 
ever, are no longer of practical significance 
because of the other actions taken in this notice. 

In consideration of the foregoing, the effective 
date of the amendment to 49 CFR Part 567, 
Certif cation, that was published on January 23, 
1976 (49 FE 3478) is changed from September 
1, 1976, to September 1, 1977, and changes are 
made to 49 CFR g .571.120 (Standard No. 120, 
Tire Selection and, Rims for Motor Vehicles 
Other Than Passenger Cars) .... 

Effective date: These changes in the text of 
the Code of Federal Regulations should be made 
immediately. 

(Sec. 103, 112, 114, 119, 201, 202, Pub. L. 89- 
563, 80 Stat. 718 (15 U.S.C. 1392, 1401. 1403, 
1407, 1421, 1422) ; delegation of authority at 49 
CFR 1.50.) 

Issued on April 29, 1976. 

Robert L. Carter 
Acting Administrator 

41 F.R. 18659 
May 6, 1976 



PART 571; S 120— PRE 6 



EfFeclive: August 27, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 120 

Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars 

(Docket No. 71-19; Notice 5) 



This notice amends Standard Xo. 120, Tire 
Selection and Rims for Motor Vehicles Other 
Than Passenger Cars (49 CFR 571.120), to per- 
mit until Februarv' 28, 1977, the equippinjr of 
new non-passenger-car veliicles with tires that do 
not meet certain tire labeling requirements but 
that otherwise meet all requirements of Standard 
No. 119 (New Pneumatic Tires for Vehicles 
Other Than Passenger Cars). 

Standard No. 120 was issued on January 19, 
1976 (41 FR 3478; January 23, 1976; Docket No. 
71-19, Notice 3). It specifies tire and rim selec- 
tion requirements for multipurpose passenger ve- 
liicles, trucks, buses, trailers, and motoi'cycles, 
and marking i-equirements for rims for use on 
these vehicles. It also adds tire and rim match- 
ing information to the items required to appear 
on such vehicles' certification labels. A staggered 
sequence of etfective dates was set out in Notice 
3, beginning with September 1, 1976. 

In Notice 4 (41 FR 18659; May 6, 1976), the 
NHTSA delayed several of these effective dates, 
to permit manufacturers to defer preparation 
for compliance with the corresponding require- 
ments pending action on petitions for recon- 
sideration of Notice 3. The NHTSA expects to 
respond to these petitions in the near future. 
Notice 4 did not, however, change the basic 
September 1. 1976, effective date of the tire and 
rim selection requirements of S5.1. Beginning 
on that date. S5.1.1 of Standard No. 120 would 
require, with an exception that is not relevant 
here, new non-passenger-car x'ehicles to be 
equipped with tires that meet either Standard 
No. 109 (which is applicable to passenger car 
tires) or Standard No. 119 (which is applicable 
to all other tires). The practical effect is to re- 
(luii'e most such vehicles to be equipped with 



Standard 119 tires, because Standard 109 tires 
are appropriate for use only on certain non- 
passenger-car vehicles. 

Standard No. 119 became effective on March 
1, 1975, with an option to delay implementation 
of its labeling requirements until March 3, 1975 
(see 40 FR 8188; February 26, 1975). 

The NHTSA has received petitions for rule- 
making from International Harvester (IH) and 
Ford Motor Company. International Harvester 
indicated that, in anticipation of the recent strike 
against the nation's four largest tire manufac- 
turers, it had accumulated an excess inventory 
of "pre-Standard 119 tires." IH stated that 
these tires meet the performance requirements 
of Standard No. 119 but not the labeling re- 
quirements. It petitioned for a six-month delay 
of the September 1, 1976, effective date of Stand- 
ard No. 120's tire selection requirements, to per- 
mit the orderly depletion of this inventory. 

Ford's petition focused on the difficulty, due 
to the strike, in obtaining in the near future 
sufficient quantities of tires that comply fully 
with Standard No. 119. Ford indicated that 
there are similar pre-Standard 119 tires avail- 
able to it. It petitioned for an amendment to 
Standard No. 120 to permit the use of such in- 
sufficiently labeled tires. 

The NHTSA believes that the approach sug- 
gested by Ford, because it will provide the 
necessary relief while preserving the required 
level of performance, is preferable to a simple 
delay of the September 1, 1976, effective date. 
Safety of performance of such tires or of vehicles 
ecpiipped with them is thus not a major issue. 
The NHTSA has determined that, while grant- 
ing the relief requested by these petitions may 
temporarily make enforcement by this agency 



PART 571; S 120— PRE 7 



EfFecHve: August 27, 1976 

more difficult and may postpone the availability 
of certain tire labeling information to users of 
new vehicles subject to Standard No. 120, the 
avoidance of a serious disruption in the truck 
manufacturing process in this situation is appro- 
priate and in the public interest. Accordingly, 
this notice adds a new section to Standard Xo. 
120 that permits, for six months, tlie use of tires 
that are not properly labeled but otherwise meet 
all requirements of Standard No. 119. 

In accordance with recently enunciated De- 
partment of Transportation policy encouraging 
adequate analysis of the consequences of regu- 
latory action (41 FR 16200; April 16, 1976), 
the agency herewith summarizes its evaluation 
of the economic and other consequences of this 
action on the public and private sectors, includ- 
ing possible loss of safety benefits. This action 
imposes no new economic or environmental costs. 
It creates the benefit of avoidance of serious 
economic disruption. In light of this benefit 
and the fact that the required level of tire per- 
formance is preserved, any loss in safety benefits 
would be insignificant in this case. 



Because of the imminent effective date of a 
requirement which would otherwise lead to 
serious economic disniption, the NHTSA for 
good cause finds that notice and public procedure 
on this amendment are impracticable and con- 
trary to the public interest. 

In consideration of the foregoing, 49 CFR 
571.120 (Standard No. 120, Tire Selection and 
Rims for Motor Vehicles Other Than Passenger 
Cars) is amended by the addition of a new 
section. . . . 

Effective date: August 27, 1976. Because this 
amendment relieves a restriction, it is found, for 
good cause shown, that an immediate effective 
date is in the public interest. 

(Sees. 103, 112, 114, 119, 201, 202, Pub. L. 89- 
563, 80 Stat. 718 (15 U.S.C. 1392, 1401, 1403, 
1407, 1421, 1422) ; delegation of authority at 49 
CFR 1.50.) 

Issued on August 27, 1976. 

Robert L. Carter 
Acting Administrator 

41 F.R. 37115 
September 2, 1976 



PART 571; S 120— PRE 8 



Effective: February 7, 1977 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 120 

Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars 
(Docket No. 71-19; Notice 6; Docket No. 75-32; Notice 2) 



This notice responds to petitions for recon- 
sideration of the newly established Standard No. 
120, Tire Selection and Rims for Motor Vehicles 
Other Than Passenger Cars, by amendments to 
the standard in the areas of tire and rim selec- 
tion, rim inakinof, and tire label information. 
A minor amendment of Part 567, "Certifica- 
tion." is also made. In addition, the decision 
tliat tlio a<>ency no lonjjer re<i:iilates mobile struc- 
ture trailers (mobile homes) is also set fortii, 
alonjj witii api)ro])riate conformin<r amendments 
of Standard No. 120, Standard No. 108, Lamps, 
Refectire Devices, and Associated Equipment, 
and § 571. .3, Definition's, of Part 571. 

Stundiud \o. 120 (49 CFR 571.120) estab- 
lishes that multipurpose passenj^er vehicles 
(MPV's), trucks, buses, motorcycles, and trailers 
shall l)e equipped with tires and rims that are 
adequate to support the fully loaded vehicle un- 
der contemplated operatin<i conditions. The 
le<j:is]ativp history of the National Traffic and 
:\Iot()r Vehicle Safety Act (the Act) (15 U.S.C. 
1381, et seq.) and §202 of that Act establish 
Coufiress' concern that uiotor vehicles could be 
equipped witli inadequate tires and that regula- 
tion would be necessary to jirotect against this 
[)i-oblem : 

Sec. 202. In standards established under 
title I of this Act the Secretaiy shall in- 
quire that each motor vehicle be equipped 
by the manufacturer or by the purchaser 
thereof at the time of the first purchase 
tiiereof in good faith for purposes other 
than resale with tires which meet the maxi- 
mum pennissible load standards when such 
vehicle is fully loaded with the maximum 
numl)er of passengers it is designed to carry 
and a reasonable amount of luggage. 



Standard No. 120 was promulgated January 
19, 1976 (41 FR 3478, Januaiy 26, 1976), and 17 
petitions for reconsideration of particular provi- 
sions were filed by vehicle, tire, and rim manu- 
facturers, and by trade associations representing 
these manufacturers. In view of the length of 
time that has been taken to respond to these 
petitions for reconsideration, the eifective dat«s 
for implementation of several of the standard's 
provisions were delayed (41 FR 18659, May 6, 
1!»76) (41 FR 36657, Augu.st 31, 1976). The 
standard's basic provision for tire and rim selec- 
tion (S5.1) was not delayed and became effective 
September 1, 1976. 

Tii^e and rim selection. The primary effect of 
Standard No. 120 is fulfillment of § 202 of the 
Act by specification of the minimum load-carry- 
ing ciiaracteristics of tires on motor vehicles not 
already subject to the passenger car tire and rim 
selection requirements of Standard No. 110, 7M'e 
Selection and Rims, of Part 571. The rim selec- 
tion requirements of the standard are limited 
(use of a rim designated as suitable by the tire 
manufacturer for use with its product; use of 
"DOT" labeled rims on and after September 1, 
1979) in anticipation of more comprehensive 
regulation of rims as part of an upcoming wheel 
standard. 

Tire selection consist of two elements: With 
one exception, each vehicle mu.st be equipped 
with tires that comply with Standard No. 119, 
Neio Pneumatic Tires for Vehicles Other Than 
Passenger Cars (or Standard No. 109, New 
Pncu mafic Tires), and the load rating of the 
tires on each axle of the vehicle must togetiier 
at least equal the gross axle weight rating 
((JAWR) for that axle. The term GAAVR is 
defined in § 571.3 of Part 571 as ". . . the value 



PART 571; S 120— PRE 9 



Effective: February 7, 1977 



specified by the vehicle manufacturer as the load- 
carrying capacity of a single axle system, as 
measured at the tire-ground interfaces." The 
GAWR concept fomaalizes the decision eacli 
manufacturer makes about the load-bearing abil- 
ity of the tires, rims, axle, brakes, and suspen- 
sion components (at a minimum) chosen to 
support and control the loaded vehicle. 

The Truck Equipment Body Distributors 
Association (TEBDA) questioned the require- 
ment that, with one exception, each vehicle sub- 
ject to Standard No. 120 be equipped with tires 
that conform to Standard No. 119 (or Standard 
No. 109). TEBDA's March 17, 1976, letter 
concerned certification of trucks equipped for 
agricultural service with Goodyear "Terra- 
Tires." The "Terra-Tire" is one example of 
tires that are placed on specialized motor ve- 
hicles which operate both on and off the high- 
way. The tires are specially designed and are 
unable to be certified to either of the tire per- 
formance standards. 

Section S5.1.1 specifies that "each vehicle 
equipped with pneumatic tires for highway serv- 
ice shall be equipped with tires that meet the 
requirement of [the tire] standard [s]. . . ." 
This language is intended to exclude from the 
requirement for Standard 119 (or 109) tires of 
those vehicles which the manufacturer (or person 
later in the chain of distribution) decides to 
equip with tires other than "tires for highway 
service." The decision is left with the manu- 
facturer at this time in view of the absence of 
data that demonstrates problems in tlie use of 
these tires that would justify their elimination. 
Any pattern of accident occurrence that points 
to unsafe utilization of non-highway service tires 
would presumably constitute a safety-related de- 
fect and could lead to revision of Standard No. 
120 to regulate them. At tliis time, the answer 
to TEBDA is that the tire selection require- 
ments of S5.1.1 (and So. 1.2 as a logical extension 
of S5.1.1) would not apply to a vehicle equipped 
witli non-highway service tires. It is emphasized 
that this exclusion from Standard No. 120 bears 
no direct relationship to the determination of 
wlietlier a particular vehicle qualifies as a "motor 
vehicle" as that term is defined in §102(3) of 
the Act. 



The second requirement for tire selection 
(S5.1.2) is that "[t]he sum of the maximum 
load ratings of the tires fitted to an axle shall 
be not less than the gross axle weight rating 
((tAWR) of the axle system. . . ." Comparable 
further specification exists when multiple ratings 
appear on the certification label, or the tires 
used on the vehicle are not listed on the certifica- 
tion label. 

Because no petition directly raised objections 
to the requirements of S5.1.2, the agency first 
addresses issues raised in a separate and out- 
standing NHTSA proposal dealing with tire 
choice and its relationship to GAWR. The ac- 
tion (Definition of "Gross Axle Weight Rating," 
40 FR .58152, December 15, 1975) proposed that 
the GAWR determination be based on, among 
other things, the vehicle's maximum attainable 
speed or the maximum load rating of the tire 
established by the tire manufacturer at 60 mph, 
whichever is lower. The proposed modification 
was intended to reflect the industry practice of 
assigning (in most cases) and labeling (in ac- 
cordance with Standards 119 and 109) a tire's 
basic load-carrying capabilities in recognition 
of the unrestricted highway speeds to which it 
is normally exposed. This formalization of 
GAWR determination was intended to prevent 
manufacturers from assigning higher capabilities 
to tii'es than their 60-mph ratings, based on 
arbitrarily low speeds. 

Most comments supported the GAWR pro- 
posal, although several truck manufacturers 
asked that the term "maximum attainaljle speed" 
be specifically defined as it is elsewhere in 
NHTSA regulations. Ford Motor Company op- 
posed the proposed change in the definition of 
GAWR as an arbitrary selection of only one of 
the many criteria that enter into the determina- 
tion of GAWR. The company suggested that 
other means exist to prevent assignment of ar- 
bitrary GAAVR's based on tire ratings other than 
those established at 60 mpli and so labeled on 
tlie tire sidewalk 

The NHTSA agrees with Ford and notes that 
tlie "other means" to regulate this practice exist 
in the tire selection requirements of S5.1.2 of 
Standard No. 120. At the time of the GAWR 
proposal. Standard No. 120 had not been made 
final. Since its implementation on September 1, 



PART 571; S 120— PRE 10 



Effective: February 7, 1977 



1976, a manufacturer is free to determine GAWR 
as in the past, but the maximum load ratings 
(marked on the tire sidewall) of tires on the 
vehicle must be at least equal the GAWR listed. 
For this reason, the XHTSA's proposal for 
amendment of the GAWR definition is con- 
sidered unnecessary and is therefore withdrawn. 
Further notice and opportunity for comment will 
precede any further action on the proposal set 
forth in that notice. 

Several issues were raised in regard to the 
GAWR proposal that should be addressed for 
purposes of clarification. The Heavy & Spe- 
cialized Carriers Conference of the American 
Trucking Associations (HSCC) cautioned the 
\HTSA against requiring an "unrestricted speed 
GAWR" on the Part 567 certification label in 
view of two State laws (or regulations) that no 
vehicle can operate on the state highways at 
gross vehicle weights greater than those listed 
on the vehicle in accordance with Federal regu- 
lations. It is conunon practice to load some 
"heavy liauler" vehicles to a gross vehicle weight 
that exceeds the unrestricted speed ratings of 
tlie vehicle tires, liecause the veliicle's tires are 
capable of carrying greater weiglit at reduced 
speeds. 

As issued, Standard Xo. 120 required that the 
maximum load ratings of the tires at least equal 
the GAWR. This effectively limits the GVWR 
to the suni of these GAWR's (except in the case 
of semi-trailers). In the agency's view, how- 
ever, the problem cited by HSCC can be avoided 
by listing additional GAWR's (calculated for 
reduced speed operation) at the end of the cer- 
tification plate following the required data on 
the label. This practice has lieen followed by 
members of the Truck Trailer Manufacturers 
Association (TT^NIA) and was confirmed as per- 
missible by tlie XHTSA in a March 5, 1975. 
letter to the TTMA. In order to aid resolution 
of issues that may arise betAveen States that wish 
to refer to tlie certification laliel and operators 
that wish to continue the additional rating sys- 
tem, the agency hereby makes an interpretive 
amendment to Part 567 to specify where addi- 
tional ratings may appear. 

Rased on this understanding of the relation- 
ship between choice of tires under S5. 1.2 of 
Standard Xo. 120 and the determination of 



GAWR under §567.4 of Part 567, a modifica- 
tion of the requirements of Standard Xo. 120 
is justified. In the case of a vehicle that is in- 
capable of the 60-mph speed used by tire manu- 
facturers to establish the maximum load rating 
that is stamped on the tire sidewall (typically a 
powered vehicle and not a trailer), it would not 
be reasonable to require the GA"\^'n"s to be 
strictlj' limited to the sum of the maximum load 
ratings of the tires on the vehicle. This is be- 
cause the vehicle will never achieve the speeds 
for which maximum load ratings were estab- 
lished. In many cases, provision is made to rat© 
tires for a greater load at the lower (but maxi- 
nuun) speed of which a veliicle is capable. In 
recognition of this extremely limited specialized 
situation, the agency amends S5.1.2 to permit 
installation of tires with reduced speed capa- 
bilities in the case of vehicles whose maximum 
attainable speed is not greater than 50 mph. 
This amendment is considered to be a technical 
adjustment of language to fully implement the 
intent of the final rule as it was established. 
A separate amendment of § 571.3 is made to 
establish the basis for determination of a ve- 
liicle's maximum attainable speeds. 

Volkswagen raised a separate issue concerning 
the requirement that the sum of maximum load 
ratings at least equal the GAWR of the axle 
system. This provision, in the case of an MPV, 
truck, bus, or trailer that is equipped with pas- 
senger car tires, requires that the maximum load 
ratings on the tires be reduced by approximately 
10 percent before calculating the sum. The pur- 
pose of this 10-percent reduction in tire rating 
is to account for the generally hareher treatment 
(impulse and surge loading in the case of MPV's 
off -road) to which the tires of a veliicle other 
tlian a passenger car are exposed that is not ac- 
counted for in passenger car tire ratings. Volks- 
wagen requested data showing that MPV's 
actually experience more abusive treatment in 
use. 

The MPV category is based in part on the ex- 
istence of characteristics that make these vehicles 
less amenable to passenger car standards. If 
Volkswagen has data indicating that the two 
categories actually experience identical usage, 
the XHTSA would prefer to adjust the defini- 



PART 571; S 120— PRE 11 



Effective: February 7, 1977 



tion to ensure that these vehicles are subject to 
all passenger car standards. Until that time, 
the existino; rationale for excusinfj these vehicles 
from some passenger car standards dictates the 
use of higher strength tires. 

As earlier noted, the rim selection require- 
ments of Standard No. 120 are not substantial, 
consisting of a recjuirement that the rims be 
listed by the tire manufacturer as suitable for 
use with its tires, and a reriuirenient that, on 
and after September 1, 1979, the rims used on a 
vehicle be labeled as specified in S5.2 of the 
standard. The September 1, 1979, date for use 
of labeled rims replaced a March 1, 1977, date 
that proved impractical in view of large inven- 
tories of unlabeled rims that exist and will exist 
long after rim labeling is begun. In establishing 
the later effective date, the agency noted that it 
was considering the possibility of eliminating 
this recjuirement entirely, to simplify the phase-in 
of pi-operly marked rims as they become avail- 
able. Experience with phase-in of newly regu- 
lated equipment in other areas such as tires and 
brake hoses has demonstrated that the require- 
ment for labeled equipment on and after a par- 
ticular date can ci'eate substantial inventory and 
potential economic waste problems. In view of 
experience that the delay of labeling require- 
ments has not substantially impeded cei-tification 
verification and defect actions, the XHTSA has 
decided to withdraw the re<iuirement (that ap- 
pears as the last sentence of S.5.1.1). It is noted 
that withdi-awal of this re(|nirement does not 
affect the I'equirenient of S5.1.2 that rims be 
listed as suitalile by the tire manufacturer for 
use with the tires with which the vehicle is 
equipped, or the requirement of So. 2 tliat rims 
be labeled with specified information. 

Mob/Jc sfructKve trailers. With regard to the 
api)licability of this standard and other stand- 
ards as a general matter, the XHTSA takes 
this opportunity to publish in the Federal Reg- 
ister its conclusion that enactment of the Xa- 
tional Mobile Home Construction and Safety 
Standards Act of 1974 (42 U.S.C. 5401 et seq.) 
(the Mobile Home Act) impliedly repealed this 
agency's autlioritv to regulate nioliile homes. 



This conclusion was announced in a May 5, 1976, 
letter to the Department of Housing and Urban 
Dexelopment that stated in relevant part: 

The National Mobile Home Construction 
and Safety Standards Act of 1974 (42 
U.S.C. 5401 et seq.) (the "Mobile Home 
Act") established within the Department of 
Housing and Urban Development a compre- 
hensive program for the regulation of mo- 
bile homes. AVe have concluded that one 
i-esidt of that statute's enactment was the 
implied repeal of the XHTSA's authority 
with respect to mobile homes. Accordingly, 
we considei- that the enactment has the effect 
of amending the Vehicle Safety Act's defi- 
nition of "motor vehicle" to exclude "mobile 
homes" as the latter term is defined in the 
Mobile Home Act. 

The effect of this conclusion is that tire and 
rim selection for mobile homes (known as "mo- 
bile structure trailers" by the XHTSA) is no 
longer subject to Standard Xo. 120 or other 
regulations issued under authority of the Act. 
For this reason, references to "mobile structure 
trailer" in Standard Xo. 120, Standard No. 108, 
Lamps, Reftcctive Devices, and Associated Equip- 
ment, and the general definitions section of Part 
571 (§571.3) are deleted. 

On the same subject, a May 25, 1976 (and 
supplementing July 7, 1976), letter from Fire- 
stone to the XHTSA asked whether tires manu- 
factured exclusively for mobile homes and tires 
that ai'e used on mobile homes (although manu- 
factured for other uses) are subject to regida- 
tion under the Act. Similar questions were 
raised as to the status of rims, some of which 
ai'e designed exclusively for use on mobile homes 
and some of which ai'e used on mobile homers 
and other vehicles. 

As for tii-es. Standard Xo. 109 applies to "tires 
for use on passenger cars" and Standard Xo. 119 
applies to "tii'es designed for highway use on 
[specified motor vehicles]." By these terms, 
neithei' standard applies to tires designed ex- 
clusively for use on mobile homes. In the case 
of tires actually used on mobile homes but de- 
signed for use also on vehicles subject to the 
Act, the agency considers such tires to be subject 



PART 571; S 120— PEE 12 



Effective: February 7, 1977 



to the standards' requirements because they con- 
stitute motor vehicle equipment as that term is 
defined in § 102(4) of the Act. 

As for rims, Standard Xo. 110 contains spec- 
ifications only for rims that equip passenger cars 
and therefore contains no requirements that 
would directly require performance of a rim that 
was installed on a mobile home. Standard Xo. 
120 applies to rims ''for use on" MPV's. tnicks. 
buses, motorcycles, and trailers (other than mo- 
bile structure trailers) and therefore would not 
apply to rims desij^ned exclusively for use on 
mobile homes. In the case of rims designed for 
use on any of tlie motor vehcile types listed, the 
XHTSA would consider Standard Xo. 120's re- 
quirements applicable, and labelin": in accordance 
with 85.2 would be required. 

Rim unarking. The second requirement of 
Standard Xo. 120 is an equipment requirement 
specifyinn; five items of information (six in the 
case of multipiece wheels) tliat nuist appear on 
any rim for use on MPV's, trucks, buses, trailers. 
or motorcycles. The requirements for location 
of the information varies according to the typo 
of information and whether the rim is i)art of 
a sinfrle or multipiece wheel. In answer to a 
question raised by Kelsey-I laves and Motor 
Wheel, it is confirmed that these markin<r ic- 
quirements have no bearinrr on the use of the rim 
on passen<i"cr cars, except as future labe]in<r re- 
quirements in Standard Xo. 110 mipht prohibit 
one or more of the items requiied liy S5.2. This 
eventuality is considered to be extremely un- 
likely. 

Based on a comprehensive review of tlie peti- 
tions for reconsideration, the apency lias decided 
that some requested modifications in labeliiifr re- 
quirements are justified. The Japanese Auto- 
mobile Manufacturers Association and Suzuki 
asked that required labeling be permitted to be 
embossed as well as impressed on tlie rim. Volks- 
wagen (and representatives from ^lotor Wheel 
and Goodyear in a February 4. 1976. ineetinjr 
with the XIITSA) asked tliat rini labelin<;- l)e 
pennitted on the disc portion of a sinple-piece 
wheel. The ajrency considers tliese suii'^restions 
to constitute justifiable options tliat would not 
diminish the level of motor veliicle safety lepre- 
sented by the standard, and the standard is ac- 
cordino:ly amended. 



Motor Wheel requested amendment of the 
standard to state that labeling of multipiece 
rims is permitted in the bolt hold area. The 
agency does not consider the addition of ad- 
visory information to lie a desirable drafting 
practice because the mention of bolt hole loca- 
tions would imply that some restriction on loca- 
tion exists when in fact it does not. In answer 
to another ([uestion from Motor Wlieel. more 
than one "rim type designation" on rim com- 
ponents of a multipiece wheel is permitted by 
the standard. 

Motor ^\nieel and Goodyear also asked if num- 
bers that contain decimals or "trailing zeroes" 
e.g., 7.50) could be shortened by deleting the 
decimal and "trailing zero." The agency believes 
that abbreviation by dropping the zero will not 
be confusing and amends the standard to include 
an example of such abbreviation. Confusion 
woidd result from dropping the decimal. 

In response to a request by Motor "\Mieel and 
Budd Company for a specific provision in S5.1.2 
that the marking requirements only apply to 
newly manufactured wheels, the agency notes the 
general applicability .statement in § 571.7, gov- 
erning the applicability of all standards found 
in Part 571, states that ". . . each standard set 
forth in subpart B of this part applies according 
to its terms to all motor vehicles or items of 
motor vehicle equipment the manufacture of 
which is completed on or after the effective date 
of the standard." Thus, the standard only ap- 
plies to rims manufactured on or after the effec- 
tive date of S5.2. 

Manufacturers asked for several revisions of 
tlie marking requirements which the agency has 
considered and concludes are unjustified. This 
discussion treats the requests in the order that 
the markings in question appear in S5.2. 

With regard to the requirement for marlcing 
with a designation that indicates the source of 
tlie rim's publisjied dimensions (S5.2(a)). Daido 
Corporation asked whether the Japanese In- 
dustrial Standards' symbol (a stylized combina- 
tion of the letters J, I, and S) or the letters 
"JIS" would meet the requirements of S5.2(a) (3) 
for use of letter "J." The agency interprets its 
labeling requirements as strictly as any other 
portion of its requirements and concludes that 



PAKT 571; S 120— PRE 13 



Effective: February 7, 1977 



neither "JIS" nor the JIS symbol would con- 
form to the requirement of S5.2(a)(3). In re- 
sponse to a similar request by Volkswagen to 
permit "DIX" in place of "D," the agency has 
considered the idea of permitting the manu- 
facturer the option of a choice of designations, 
and concludes they are undesirable in the in- 
terests of maintaining uniformity and compre- 
hension. 

Grove Manufacturing suggested that the single 
letter designations of "D" and "E" could be 
mistaken for the load ranges that appear on 
tires and on the certification label. The agency 
concludes that the designations on the rim are 
sufficiently separated to preclude confusion and 
therefore the recommendation by Grove is not 
undertaken. 

The "rim size designation" required by S5.2(b) 
is defined in S4 to mean the rim diameter and 
width. Daido and Volkswagen asked that a 
width designation followed by a diameter desig- 
nation be considered as satisfying the requirement 
for designation of diameter and width. The 
agency specified the existing order to distinguish 
rim designations from tire designations. This 
order of information is being considered as the 
uniform practice to be adopted by the Inter- 
national Standards Organization. For reasons 
of uniformity, the requests are denied. 

Volkswagen asked that tlie "DIN" symbol be 
permitted to signify compilance of the rim with 
Standard Xo. 120 in i)]ace of the "DOT" symljol 
required by S5.2(c) for this purpose. Tlie 
agency does not find that the requirement of 
§ 114 of the Act for certification is satisfied by 
use of a designation that has a wholly different 
meaning. Volkswagen's request is tlierefore 
denied. 

Cerfif cation lohel. The tliird requirement of 
Standard Xo. 120 is that information about suit- 
able tires and rims for use on the \'ehicles, along 
with appropriate inflation pressure and speed 
restriction information, be placed on a label on 
the vehicle (S5..S). As amended April 29, 197fi 
(41 FR 18659. May fi. 1976). the standard re- 
quires that the information appear on the cer- 
tification labels of veiiicles manufactured on or 
after September 1, 1977. 



Some manufacturers and the Truck Trailer 
IManufacturers Association (TTMA) objected to 
the provision of this information on grounds 
that valid information already appears on the 
tires and rims that equip the vehicle, and that 
the information could mislead a person to think 
that only the listed tires and rims could be used 
on the vehicle. "With regard to the first objec- 
tion, the XHTSA disagrees and notes that an 
improper choice of tires or rims (as could occur 
by replacing origmal equipment with "custom" 
rims or the equivalent in tires) could perma- 
nently mislead vehicle owners as to the suitable 
selection of tires and rinis. As for the possi- 
bility of misleading, the agency believes that a 
heading over the tire-rim listings (specifically, 
"SUITABLE TIRE-RIM CHOICE") can be 
added to the requirements for optional use by a 
manufacturer who believes the information 
would be otherwise misleading. With regard 
to General Motors' note that an owner should 
be guided by all available information on tire 
choice (e.g., information in the owner's manual), 
the agency notes its longstanding position that 
manufacturers may add statements referring the 
reader to other publications for additional in- 
formation. 

It is apparent from the examples cited by 
manufacturers tliat the decision to place all re- 
quired data on the certification label could prove 
cumbei'some in some cases, particularly those in- 
volving a heavy truck with several available axle 
combinations. In view of these problems, the 
agency has decided to remove the restriction on 
location and permit the information to appear 
on the certification label or on a separate label 
that conforms to the requirements for certifica- 
tion labels. The NHTSA notes tliat this option 
to provide information on a separate lalw-1 re- 
sponds to concern of the Truck Body and 
Equipment Association (TBEA) for the respon- 
sibilities of its final-stage manufacturing mem- 
bership. The agency does not believe the tire 
and rim information would be as useful in a 
location entirely separate from the certification 
label, and it therefore declines to adopt General 
Motors' suggestion to use the Vehcile Identifica- 
tion label. 



PART 571; S 120— PRE 14 



Effective: February 7, 1977 



Motorcycle manufacturers and General Motors 
pointed out that the requirements for listing tire 
and rim information after GVWR in the case 
of vehicles such as motorcycles, that only utilize 
one GVWR listin<r, is redundant and therefore 
wasteful of space. Other manufacturers sug- 
gested that the tire-rim information was redun- 
dant in the case of multiple GVWE listings, 
although this is not the case because of the 
need to associate the appropriate GVWR with 
GAWR's that may exceed the GVWR. In any 
event, these comments suggest that GVAVR and 
GAWR could be better linked by revision of the 
example format to reduce the amount of infor- 
mation that must l)e listed. The solution is to 
permit listing of the GVWR alone, followed 
immediately by corresponding GAWR's and ap- 
propriate tii'e-rim information. The clearer for- 
mat would be used for single and multiple 
listings. This revision is described in the new 
exaniplo that accompanies the rule changes at 
the end of this notice. In conformity with this 
simplification, the rule is also amended to delete 
the requirements for GA'^VR tire-rim-inflation 
listings. Depending on manufacturers' reactions 
to the simplified format, a similar change could 
be undertaken for the passenger car example 
found in Part .567 (§ 567.4(h) (1)). 

With regard to the items of information that 
must be listed in accordance with S5.3, General 
Motors and the TTIMA argued that "tires . . . 
appropriate an a mini^niim for the GAWR" 
[emphasis added] could be construed to require 
tires with load ratings less than those that the 
mannfactiirer would choose to recommend. To 
eliminate any ambiguity, the agency replaces 
"at a minimum" with "as specified by S5.1.2." 

Suzuki asked whether "cold inflation pressure" 
means the maximum inflation pressure specified 
by the tire manufacturer. The TTMA also 
asked for clarification on this point. The answer 
is that the requii-ement does not call for maxi- 
mum pressure, but the pressure specified by the 
tire manufactiirer as sufficient to carry the load 
specified by the vehicle manufacturer as the tire's 
share of the assigned GAWR. 

Michelin Tire Corporation noted that listing 
inflation pressure could be misleading in the case 
of tire designations that call for different in- 
flation pressures depending on the tire construc- 



tion. It is the agency's view that any possibility 
of confusion can easily be avoided by an indica- 
tion that the tire designation represents a radial 
tire, so that a person substituting a non-radial 
tire size with the same designation is aware that 
the two tires are not identical. 

The TBEA requested clarification of the term 
"maximum speed" as it appeared in the example 
that accompanied the final rule. The TBEA 
appeared to misunderstand the example as a ref- 
erence to the speed capabilities of the vehicle 
instead of the speed restriction of the tires. The 
agency has in mind only the rare tire types con- 
structed for transit buses and mining and log- 
ging oi>erations and so designated. Goodyear 
and the TTMA appeared to have the same mis- 
taken impression of the requirement. 

Speed-restricted vehicles have now been ad- 
dressed under 85.1.2. In view of the confusion 
that arose over the requirement, and the agency's 
assumption that the users of these tires are 
knowledgeable in the use of the tires, it has been 
decided to drop the requirement of S5.3(d) al- 
together. 

The TTMA raised several other questions with 
regard to the information that appears along 
with the GAWR. In answer to these questions, 
the effective dates of the standard are such that 
the manufacturer will lie required to list the 
information specified by S5.3 on and after Sep- 
tember 1, 1977. Also, it is not permissible to 
"bracket" the GVWR and GAWR values for 
a particular vehicle by specifying the minimum 
and maximum values that any tire-rim choice 
could provide. Section 567.4 of Part 567 re- 
([uires that the GVWR and GAWR's repre- 
senting the manufacturer determinsition of the 
particular vehicle's characteristics must be listed. 

The standard does not require the information 
specified in .Sa.S to be listed alongside the addi- 
tional GVWR's and GAWR's that a manufac- 
turer might list at the end of its certification 
label as reduced speed ratings. Lastly, the 
agency does not agree that the GAWR ratings 
for a semi-trailer are not related to the trailer's 
GVWR. AVhile the trailer's axles do not support 
the entire weight of the vehicle, it is still the 
case that the various GVWR's that could be as- 
signed to a semi-ti-ailer are affected by the 



PART 571; S 120— PRE 15 



Effective: February 7, 1977 



GAWE values that can be assiiSTied, and that 
the GVWR probably differs depending on the 
GAWR value assigned. In this sense the 
GAWR's assigned to a semitrailer's axles do 
"correspond" to its GVWR. 

In accordance with Department of Transpor- 
tation policy encouraging adequate analysis of 
the consequences of regulatory action (41 FR 
16200, April 16, 1976), the agency herewith sum- 
marizes its evaluation of the economic and other 
consequences of this action on the public and 
private sectors, including possible loss of safety 
benefits. The new options, simplification, and 
reduction of marking and labeling requirements 
should make compliance with the standard less 
costly, while the changes are not expected to 
significantly reduce the level of motor vehicle 
safety. The exception for speed-restricted ve- 
hicles provided in S5.1.2 represents a correction 
of the requirements to reflect the agency's in- 
tent not to prevent the assignment of greater 
load-carrying capabilities to vehicles at lower 
speeds. Permitting this practice to continue will 
result in the avoidance of new costs in the 
economy. 

In consideration of the postponement of effec- 
tive dates already granted for rim marking and 



the tire information labeling, the agency con- 
cludes that the present effective date schedule 
permits adequate time for compliance. 

In view of the three notices that have modi- 
fied the test of Standard No. 120, the entire 
standard (incorporating the amendments made 
by this notice) is published for the convenience 
of persons affected. 

In consideration of the foregoing, Chapter V 
of Title -19, Code of Federal Regulations, is 
amended. . . . 

Effective date : Changes to the text of the Fed- 
eral Register may be made immediately. The 
provisions of Standard No. 120 are in effect at 
this time, except as othei'wise provided in the 
standard. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR1.50.) 

Issued on January 28, 1977. 

John W. Snow 
Administrator 

42 F.R. 7140 
February 7, 1977 



PART 571; S 120— PRE 16 



MOTOR VEHICLE SAFETY STANDARD NO. 120 



Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars 



51. Scope. This standard specifies tire and 
rim selection requirements and rim marking re- 
quirements. 

52. Purpose. The purpose of this standard is 
to provide safe operational performance by en- 
suring that vehicles to which it applies are 
equipped with tires of adequate size and load 
rating and with rims of appropriate size and 
type designation. 

53. Application. This standard applies to 
multipurpose passenger vehicles, trucks, buses, 
trailers, and motorcycles, and to rims for use on 
those vehicles. 

54. Definitions. All terms defined in the Act 
and the rules and standards issued under its 
authority are used as defined therein. 

"Rim base" means the portion of a rim re- 
maining after removal of all split or continuous 
rim flanges, side rings, and locking rings that 
can be detached from the rim. 

"Rim size designation" means rim diameter 
and width. 

"Rim diameter" means nominal diameter of 
the bead seat. 

"Rim width" means nominal distance between 
rim flanges. 

"Rim type designation" means the industry or 
manufacturer's designation for a rim by style or 
code. 

"Weather side" means the surface area of the 
rim not covered by the inflated tire. 

55. Requirements. 

S5.1 Tire and rim selection. 

S5.1.1 Except as specified in S5.1.3, each ve- 
hicle equipped with pneumatic tires for highway 
service shall be equipped with tires that meet the 



requirements of Standard No. 109 (§ 571.109) or 
Standard No. 119 (§ 571.119), and with rims 
that are listed by the manufacturer of the tires 
as suitable for use with those tires, in accordance 
with S4.4 of Standard No. 109 or S5.1 of Stand- 
ard No. 119, as applicable. 



S5.1.2 Except in the case of a vehicle which 
has a speed attainable in 2 miles of 50 mph or 
less, the sum of the maximum load ratings of 
the tires fitted to an axle shall be not less than 
the gross axle weight rating (GAWR) of the 
axle system as specified on the vehicle's certifica- 
tion label required by 49 CFR Part 567. If the 
certification label shows more than on GAWR 
for the axle system, the sum shall be not less 
than the GAWR corresponding to the size desig- 
nation of the tires fitted to the axle. If the size 
designation of the tires fitted to the axle does 
not appear on the certification label, the sum 
shall be not less than the lowest GAWR appear- 
ing on the label. When a tire listed in Appendix 
A of Standard No. 109 is installed on a multi- 
purpose passenger vehicle, truck, bus, or trailer, 
the tire's load rating shall be reduced by divid- 
ing by 1.10 before calculating the sum. 



S5.1.3 In place of tires that meet the re- 
quirements of Standard No. 119 a truck, bus, or 
trailer may, at the request of the purchaser, be 
equipped at the place of manufacture of the ve- 
hicle with used tires owned or leased by the pur- 
chaser if the sum of the maximum load ratings 
meet the requirements of S5.1.2. On and after 
January 1, 1978, used tires employed under this 
provision must be originally manufactured to 
comply with Standard No. 119, as evidenced by 
the DOT symbol. 



PART 571; S 120-1 



S5.2 Rim marking. On and after August 1, 
1977, each rim or, at the option of the manufac- 
turer in the case of a singlepiece wheel, wheel 
disc shall be marked with the information listed 
in paragraphs (a) through (e), in lettering not 
less than one-eighth inch high, impressed to a 
depth or, at the option of the manufacturer, 
embossed to a height of not less than 0.005 
inch. The information listed in paragraphs (a) 
through (c) shall appear on the weather side. 
In the case of rims of multipiece construction, 
the information listed in paragraphs (a) through 
(e) shall appear on the rim base and the in- 
formation listed in paragraphs (b) and (d) shall 
also appear on each part of the rim. 

(a) A designation which indicates the source 
of the rim's published nominal dimensions, as 
follows: 

(1) "T" indicates The Tire and Rim Asso- 
ciation. 

(2) "E" indicates The European Tyre and 
Rim Technical Organisation. 

(3) "J" indicates Japanese Industrial Stand- 
ards. 

(4) "D" indicates Deutsche Industrie Norm. 

(5) "M" indicates The Society of Motor 
Manufacturers & Traders, Ltd. 

(6) "B" indicates British Standards Insti- 
tution. 

(7) "S" indicates Scandinavian Tire and 
Rim Organization. 

(8) "N" indicates an independent listing 
pursuant to S4.4.1(a) of Standard No. 109 or 
S5.1(a) of Standard No. 119. 

(b) The rim size designation, and, in case of 
multipiece rims, the rim type designation. For 
example: N 20 x 5.50, or N 20 x 5.5. 

(c) The symbol DOT, constituting a certifi- 
cation by the manufacturer of the rim that the 
rim complies with all applicable motor vehicle 
safety standards. 

(d) A designation that identifies the manu- 
facturer of the rim by name, trademark, or 
symbol. 



(e) The month, day, and year, or the month 
and year, of manufacture, expressed in numerals. 
For example, 

"September 4, 1976" may be expressed as: 

90476, 904 ^^ 76 
76 904 

"September 1976" may be expressed as: 

9 or '^ 
76 9 



976, 



S5.3 Label information. (For vehicles manu- 
factured on and after September 1, 1977) The 
information specified in S5.3.1 through S5.3.3 
shall, in the format set forth following this sec- 
tion, appear either— 

(a) After each GAWR listed on the certifica- 
tion label required by § 567.4 or § 567.5 of this 
chapter, or at the option of the manufacturer, 

(b) On a tire information label affixed to the 
vehicle in the manner, location, and form de- 
scribed in § 567.4(b) through (f) of Part 567 
of this chapter, as appropriate for each GVWR- 
GAWR combination listed on the certification 
label. 

55.3.1 The size designation of tires (not 
necessarily those on the vehicle) appropriate (as 
specified in S5.1.2) for the GAWR. 

55.3.2 The size designation and, if applicable, 
the type designation of rims (not necessarily 
those on the vehicle) appropriate for those tires. 

55.3.3 Cold inflation pressure for those tires. 

Truck example 

SUITABLE TIRE-RIM CHOICE 

GVWR: 17280 

GAWR: Front-6280 with 7.50-20(D) tires, 
20 X 6.00 rims, at 75 psi cold single 

GAWR: Rear-11000 with 7.50-20(D) tires, 
20 X 6.00 rims, at 65 psi coul dual. 

GVWR: 17340 

GAWR: Front-6300 with 7.00-20(E) tires, 
20 X 5.50 rims, at 90 psi cold single 

GAWR: Rear-11040 with 7.00-20(E) tires, 
20 X 5.50 rims, at 80 psi cold dual. 



PART 571; S 120-2 



S6. Vehicles manufactured from September 1, tires that meet Standard No. 119 (§ 571.119), the 

1976, to February 28, 1977. Notwithstanding any vehicle may be equipped with tires that meet every 

other provision of this standard, a vehicle to which requirement of that standard other than the tire 

this standard applies that is manufactured during marking requirements of S6.5 of that standard, 
the period from September 1, 1976, to February 

28, 1977, shall meet each requirement of this 41 F.R. 3478 

standard, with the following exception: In place of January 23, 1976 



PART 571; S 120 3-4 



i 



EffacHv*: January I, 1973 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems — Trucks, Buses and Trailers 

(Docket Nos. 70-16, 70-17; Notice No. 2) 



The purpose of this notice is to amend § 571.21 
of Title 49, Code of Federal Regulations, by 
adding Motor Vehicle Safety Standard No. 121, 
Air Brake Systems — Trucks, Buses and Trailers. 
Notices of proposed rulemaking on this subject 
were published on June 2.5, 1970 (35 F.R. 10368) 
and June 26, 1970 (35 F.R. 10456). The com- 
ments received in response to the notices and 
information obtained at a technical conference 
held on October 20, 1970 (35 F.R. 14736, Septem- 
ber 22, 1970) have been considered in the devel- 
opment of the final rule. The trailer require- 
ments are joined with the truck and bus 
requirements in a single air brake systems 
standard. 

The standard as adopted specifies requirements 
for the safe performance of air brake systems 
under normal and emergency conditions. It 
should be noted that the term "air brake system" 
as defined in the standard applies to the brake 
configuration commonly referred to as "air over 
hydraulic," in which failure of either medium 
can result in complete loss of braking ability. 

The standard establishes a set of requirements 
to govern the braking behavior of a vehicle dur- 
ing application of the service brakes. Principal 
among these are stopping performance require- 
ments that include a minimum stopping distance 
requirement for trucks and buses and lateral 
stability and wheel lockup requirements for all 
vehicles. To more accurately reflect the friction 
characteristics of a surface with a skid number 
of 75, the s(topping distances for trucks and buses 
on a dry surface have been increased over those 
proposed in the notice. The required distance 
from 60 m.p.h. is now 245 feet rather than 216 
feet and the distance from 20 m.p.h. is 33 feet 
rather than 29 feet. The stopping distance on a 
wet surface at 20 m.p.h., 54 feet, has been re- 



tained. Several comments indicated that there 
are no test facilities on which the 60 m.p.h. stop 
on a wet surface can be safely conducted. As a 
measure of brake efficiency, moreover, the 20 
m.p.h. stop on a wet surface satisfactorily indi- 
cates the vehicle's behavior at higher speeds, and 
the standard therefore specifies only the 20 
m.p.h. stopping distance test. 

The requirement that the vehicle stay within 
a 12-fbot-wide lane has been adopted as pro- 
posed. The proposed requirement that no wheel 
lock except momentarily has been modified to 
permit lockup to occur on the leading nonsrteer- 
able axle on vehicles having more than two non- 
steerable axles. A review of available informa- 
tion indicates that satisfactory control of the 
vehicle can be maintained if lockup is avoided 
on two nonsteerable axles. The rule also permits 
lockup at speeds under 10 m.p.h. Such low speed 
lockup is not considered hazardous and allows 
greater flexibility in brake system designs. 

Some comments stated that the requirement 
for a controlled stop without lockup favored one 
variety of stability-controlling device — the anti- 
lock device — over other systems such as load 
proportioning devices. Several comments seemed 
to assume that the proposal required antilock 
devices. The requirement that the vehicle stop 
without locking its wheels reflects the Adminis- 
tration's judgment that a vehicle with locked 
wheels, whatever its equipment, is unstable and 
uncontrollable in an emergency situation. The 
Administration recognizes the likelihood that 
manufacturers of some types of vehicles may 
have to incorporate proportioning or antilock 
devices into their systems in order to meet the 
stopping distance requirement. However, the 
manner in which lockup is prevented is not 
specified in the standard, and if a proportioning 



PART 571; S 121— PRE 1 



Effective: January 1, 1973 



device or any other device can produce the de- 
sired result, it may be incorporated into the 
vehicle's braking system. 

Although an antilock device is not required, 
if it is used on a vehicle it must conform to sev- 
eral requirements. A warning signal must be 
provided to warn of total system failure, a failed 
dence must not interfere with the operation of 
the service brake, and electrical elements in the 
system must be powered through the vehicle's 
stop lamj) circuit. Of these requirements, the 
first was the subject of comments that indicated 
some uncertainty as to the nature of a total sys- 
tem failure. The reason for the requirement is 
that a driver ought to be warned in the event 
that a system on which he has come to rely has 
stopped working altogether. Monitoring of each 
device separately would be difficult and costly, 
while monitoring of the shared elements of the 
syst«m, such as the electrical circuitry, would be 
relatively simple. Although electrical problems 
would be the most likely cause of total failure, 
other components may also produce such failure 
and the language of the requirement has not 
been limited to a specific type of failure. A 
requirement that electrical power for antiskid 
devices on trailers must be provided through the 
stop lamp circuit has been added to insure the 
functioning of antilock systems in vehicle com- 
binations in which the towed vehicle has an anti- 
lock system. 

The requirements for actuation and release 
times, for brake retardation force, and for brake 
power have been modified somewhat in the light 
of infonnation provided by the comments. The 
notice proposed timing curves for brake actuation 
and release, but subsequent review has indicated 
that adhesion to a timing curve is less significant 
than the basic ability to apply and release the 
brakes quickly. The curves ha\^ therefore been 
omitted in favor of a single application time of 
0.25 second and a single release time of 0.50 
second. These values are somewhat less stringent 
than those proposed in the notice, and reflect 
the judgment that a system that can meet the 
stopping distance requirements without lockup 
has less need for the rapid times originally pro- 
posed. Vehicles intended to tow other vehicles 
equipped with air brakes must still meet the 
actuation and release times with a 50-cubic-inch 



test reservoir attached to the service line outlet, 
but the requirements for pressurization of the 
test reservoir itself have been deleted. 

The brake retardation force requirement was 
the subject of numerous comments, some to the 
effect that the retardation force was too high to 
permit safe operation of vehicle combinations in 
which new and old vehicles are mixed, and others 
to the effect that the forces were too high to be 
achieved with reliability by available friction 
materials. The Administration has determined 
that compatibility problems are substantially 
lessened if the vehicle has the ability to stop 
without locku}) and that the retention of a rela- 
tively high retardation force requirement will 
not lead to significant compatibility problems. 
It has been determined, however, that the stop- 
ping distance requirements can be met by brakes 
having a somewhat lower retardation force ca- 
pacity than proposed, and a lower force require- 
ment is therefore adopted. 

Comments regarding the proposed brake power 
requirements stated that the fade characteristics 
required of the linings might exceed the limits 
of existing technology and might not be com- 
patible with the retardation force requirements. 
In the light of these comments and other infor- 
mation it has been determined that the brake 
power requirements should be reduced. Accord- 
ingly the standard as adopted requires 10 de- 
celerations at a rate of 9 feet per second per 
second at intervals of 72 seconds with the air 
pressure at 90 p.s.i. or less, and a final decelera- 
tion at 14 f.p.s.p.s. from 20 m.p.h. with a service 
line air pressure of 108 p.s.i. or less. In the 
light of the diminished power requirements, the 
recovery requirements have been retained with a 
minor adjustment from 45 p.s.i. to 40 p.s.i. in the 
minimum air pressure required. 

A series of alterations have been made in the 
equipment requirements in response to comments 
and as a result of reevaluation by the Adminis- 
tration. First among these is the alteration of 
the stop lamp switch requirement to permit use 
of a pneumatic switch. The requirements for 
compressor capacity have been modified to re- 
quire it to increase air pressure in the reservoirs 
from 85 p.s.i. to 100 p.s.i. in not more than 25 
seconds, in place of the proposed requirement of 
0-85 p.s.i. in 2 minutes. The maindatory require- 



PART 571; S 121— PRE 2 



Effective: January 1, 1973 



ment for a supply reservoir has been removed, 
and the overall reservoir capacity for trucks and 
buses has been reduced to 12 times the combined 
brake chamber capacity. The drain valve re- 
quirement has been simplified, the tolerance on 
the air pressure gauge has been broadened to 
±7 percent of the compressor cut-out pressure, 
and the low air pressure warning requirement 
has been modified to permit visible, nonaudible 
signals within the driver's forward field of view. 
The notice proposed that each truck arid bus 
have a split service brake system. It has been 
determined that the additional cost and greater 
complexity of a split system on vehicles equipped 
with air brakes are not accompanied by safety 
benefits great enough to justify requiring a split 
system. Accordingly, the requirement has been 
deleted. The remaining system with emergency 
capabilities is the parking brake system, and it 
has been determined that a parking brake system 
complying with the applicable requirements of 
the standard will provide a safe means of stop- 
ping the vehicle in the event of service brake 
failure. 

Two aspects of the parking brake system were 
the subject of considerable comment. A number 
of comments stated that no maximum static re- 
tardation force should be specified, and several 
comments stated that the parking brakes should 
not apply automatically. The standard as 
adopted retains both the maximum retardation 
and the automatic application requirements. 
Each has a role in the safe operation of the 
parking brake system. If no maximum retarda- 
tion force were specified, there would be consid- 
erable risk of lockup during emergency braking. 
The requirement as adopted, however, raises the 
upper limit on the quotient 

static retardation force 
GAWR 

from 0.33 to 0.40. 

Comments stated that automatic application 
of the brakes while the vehicle is in motion could 
induce hazardous instability, due to wheel lockup 
or to the unexpected nature of the braking. It 
has been determined that adequate safeguards 
exist in the standard to avoid such problems. 
The required low pressure warning signal must 
operate at a pressure well above the automatic 



application pressure so that the driver will have 
sufficient warning of incipient brake application. 
In addition, the limit on retardation force will 
act to prevent lockup under all but the most 
severe conditions. With respect to trailers, the 
automatic functioning of the parking brake sys- 
tem is further insured by the deletion of the 
proposed requirement for a check valve or similar 
device to protect the trailer's air pressure. 

The parking brake controls have been consid- 
erably simplified by uniting in one control the 
manual on-off operation and the release-after- 
automatic-application function. 

Many comments revealed a misunderstanding 
about the Administration's purpose in specifying 
test conditions. It should be understood that the 
standards are not instructions for, or descrip- 
tions of, manufacturer tests. For example, the 
condition that states that "(t)he wind velocity is 
zero," simply means that the vehicle must meet 
the applicable tests if (among other things) the 
air is still, that is, if the wind neither helps nor 
hinders the vehicle's performance. One way in 
which the manufacturer could check his vehicle's 
conformity with reference to the zero wind con- 
dition is to run the braking test with a resultant 
tailwind. With reference to another condition, 
such as the surface with a skid number of 75, the 
test could be run on a surface having a skid 
number lower than 75. Manufacturers are re- 
quired to exercise due care to insure that their 
vehicles will meet the standard if tested by the 
Administration under the specified conditions, 
but they are at their own discretion in devising 
an appropriate testing program for that purpose. 

A few changes have been made in the test 
conditions. The notice had proposed, in addition 
to the zero wind condition, that the vehicle stay 
in the roadway with a wind of 30 m.p.h. from 
any direction. On review, the 30-m.p.h. speed 
has been determined to be excessive and to un- 
duly increase the problems of testing. In addi- 
tion, most stability problems are controlled by 
preventing wheel lockup, as required by the 
Standard, and the crosswind condition has there- 
fore been deleted. In place of the "lightly 
loaded vehicle weight," a weight condition based 
on the vehicle's unloaded weight is used. 

Effective date. Because of the development 
work and preparation for production that this 



PART 571; S 121— PRE 3 



Effective: January 1, 1973 



standard will require, it is found that an effective 
date later than 1 year from the date of issuance 
is in the public interest. Accordingly, the stand- 
ard is effective January 1, 1973. 

In consideration of the above, § 571.21 of Title 
49 of the Code of Federal Regulations is amended 
by adding Motor Vehicle Safety Standard No. 
121 as set forth below. This standard is issued 
under the authority of sections 103 and 119 of 
the National Traffic and Motor Vehicle Safety 
Act, 15 U.S.C. 1392, 1407, and the delegation of 
authority by the Secretary of Transportation to 



the National Highway Traffic Safety Adminis- 
trator, 49 CFE 1.51. 

Issued on February 19, 1971. 

Douglas W. Toms, 

Acting Administrator, National 
Highway Traffic Safety Ad- 
ministration 

36 F.R. 3817 
February 27, 1971 



I 

1 



( 



PART 571; S 121— PRE 4 



EflacHva: Scptambar 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems — Trucks, Buses, and Trailers 

(Dockets No. 70-16 and 70-17; Notice 3) 



The purpose of this notice is to respond to 
petitions requesting reconsideration of Motor 
Vehicle Safety Standard No. 121, Air Brake 
Systems, § 571.121 of Title 49, Code of Federal 
Regulations. After issuance of the standard on 
February 19, 1971 (36 F.R. 3817, February 27, 
1971), petitions for reconsideration were filed 
pursuant to 49 CFR 535.35 by a number of ve- 
hicle and equipment manufacturers. This notice 
grants some of the requests by amending the 
standard, and denies other requests. 

1. Service brake system. The service brake 
system requirements have been reorganized for 
reasons of clarity and have been amended with 
respect to the order of testing and the number of 
tests to be conducted. The dynamometer tests 
have been separated from the road tests and 
placed in section S5.4. The road test section has 
been amended to specify the order in which the 
stopping tests are to be run. The section is 
further amended to provide that a truck or bus 
will be stopped six times for each combination of 
loading, speed and road conditions and that it 
will be considered to meet the requirement if one 
stop is made in the required distance with the 
required stability and freedom from wheel lock- 
up. This amendment has been adopted to ease 
the problems arising from a test driver's un- 
familiarity with a vehicle's behavior. To ac- 
comodate antilock systems that permit some 
wheels to lock for longer periods than others, the 
reference to "momentary" lockup in S5.3.1 and 
S5.3.2 has been amended to refer to "controlled" 
lockup. 

S5.3.2, Stopping Capability, Trailers, has been 
amended in minor respects, to make it clear that 
the 90 p.s.i. pressure level is system-wide and not 
confined to the brake control lines, and to provide 
that the trailer is to stop the combination of 



vehicles without benefit of the towing vehicle's 
brakes. 

The brake power requirements of S5.4.2 and 
the dynamometer test conditions of S6.2 are each 
amended to refer to the drum "or disc" to avoid 
the possibility that the sections would be miscon- 
strued as requiring dnmi brakes. The brake re- 
covery requirements of S5.4.3 are amended by 
lowering the minimum air pressure requirement 
to 20 p.s.i. from 40 p.s.i. This amendment is 
based on a reassessment of the problems asso- 
ciated with over-recovery that has led the 
NHTSA to conclude that 20 p.s.i. is a reasonable 
level. 

The requirements concerning antilock system 
failure and the provision of power for antilock 
systems on trailers have been separated from the 
other service brake requirements and placed in 
S5.5. 

2. Service brake retardation force. The stand- 
ard as adopted in February 1971 required the 
brakes on each axle to produce specified retarda- 
tion forces at each of several brake chamber air 
pressures. As indicated in the issuance of the 
standard, the primary goal of the retardation 
force requirement was to insure brake compat- 
ibility between vehicles used in combination. On 
review of petitions requesting exemption of ve- 
hicles that do not tow other vehicles from the 
retardation force requirements, the NHTSA has 
determined that for these vehicles the require- 
ments are not necessary. Accordingly, S6.4.1 is 
amended to apply only to vehicles that are in- 
tended to tow or to be towed by another vehicle 
equipped with air brakes. 

In response to petitions objecting to axle by 
axle force calculations, the retardation force re- 
quirements are further amended to provide that 
the retardation force for all axles shall be added 



PART 571; S 121— PRE 6 



Effactiv*: Saptombar 1, 1974 



together and divided by the sum of gross axle 
ratings to arrive at the values shown in Table 
III. The eflFect of the amendment is to allow 
greater flexibility in the allocation of braking 
force between axles. 

The overall braking force required of the ve- 
hicle's brakes, however, remains the same as 
before. The NHTSA has considered and re- 
jected the requests for different retardation 
values and for substitution of SAE J992a for 
the dynamometer tests of S5.4.1. The present 
retardation force requirements in Table III are 
considered to be a reasonable accommodation be- 
tween the need for compatibility with existing 
vehicles and the need to establish a uniform 
pattern of brake response over the range of 
operating pressures. The djTiamometer pro- 
cedures of S5.4.1.1, which permit measurement 
of brake forces on an individual vehicle, are 
more suited to the regulatory purpose of this 
standard than are the procedures of SAE 
J 992a, which provides for road testing of ve- 
hicles in combination. The agency recognizes 
that the availability of dynamometers of suf- 
ficient capacity is a concern to many petitioners, 
but available evidence indicates that dynamom- 
eter access will not be a major long-term 
problem. The petitions to delete dynamometer 
testing are therefore denied. 

3. Parking irake system. The parking brake 
system required by S5.4 of the standard had 
several features that were widely objected to by 
the petitioners. In particular, petitioners ob- 
jected to the requirement for automatic applica- 
tion of the parking brakes in the event of pres- 
sure loss. Although the standard specified a 
maximum retardation force level of 0.40 to re- 
duce the possibility of lockup during automatic 
application, many petitioners stated that auto- 
matic application of the brakes would surprise 
the driver and adversely affect his handling of 
the vehicle. 

The NHTSA remains convinced that auto- 
matic application of the parking brake is a 
satisfactory means of providing braking in the 
event of service brake failure. The low pressure 
warning signal required by S5.1.5 is considered 
adequate to warn a driver of impending applica- 
tion of the parking brake to avoid most of the 
effects of surprise. However, review of the peti- 



tions has persuaded the agency that automatic 
application of the parking brake need not be 
mandatory. Accordingly, the standard is 
amended to provide for an alternative parking 
brake system that is manually, and not auto- 
matically, applied. 

To accommodate the new alternative, the 
parking brake requirements have been reorga- 
nized into two main sections: S5.6, which 
specifies requirements for parking brakes gen- 
erally, and S5.7, which sets out the emergency 
braking capabilities for automatic systems 
(S5.7.1) and manual systems (S5.7.2) on trucks 
and buses. A third section (S5.8) deals with 
the emergency braking of trailers. 

The general requirements of S5.6 are derived 
from S5.4 of the original standard, with some 
additions and amendments. The braking force 
generated by the parking brakes is measured, at 
the manufacturer's option, either by a static 
draw bar test, which must produce a force level 
of 0.28, or by a holding test on a 20% grade. 
The tests are to be conducted in both forward 
and rearward directions. As provided in the 
original standard, the parking brakes must be 
applied by an energy source that is independent 
of the air pressure in the service brake system. 

Additional changes have been made in S5.6 
with respect to the requirements for the parking 
brake control. The standard as published in 
February 1971 specified the shape and color of 
the parking brake control, as well as its location, 
and provided that manual operation and release 
after automatic application should be accom- 
plished by movement of a single control. After 
review of the petitions, it has been decided to 
allow greater flexibility in the design and op- 
eration of the control. Efforts are now imder- 
way within the industry to standardize controls, 
and it may be that a consensus will be reached 
upon which a more standardized control can be 
based. In the meantime, the standard's specifica- 
tions have been reduced to requiring the control 
tc be separate from the service brake control, 
operable from the normal driving position, and 
identifiable as to its method of operation. The 
shape, color, and number of controls, and the 
method of operation, are left to the judgment of 
the manufacturer. 



PART 571; S 121— PRE 6 



Effactiv*: S«pt*nib«r 1, 1974 



The major difference between the emergency 
braking performance required of a vehicle with 
a manual system and the performance required 
of a vehicle with an automatic system is that a 
vehicle with a manual parking brake is required 
by S5.7.2.3 to meet a stopping distance test with 
an air pressure failure in the service brake sys- 
tem. Although a manufacturer may elect to use 
the parking brakes to provide this emergency 
stopping capacity, he may use other components 
to supplement the parking brakes or he may use 
a system entirely independent of the parking 
brakes. 

A vehicle with an automatic parking brake 
may, at the manufacturer's option, either meet 
the stopping distance test of S5.7.2.3, or have a 
maximum static retardation force not greater 
than 0.40, measured in accordance with S5.6.1. 
Several petitioners requested deletion of the 
maximum retardation force levels for automatic 
brakes. Although the agency remains concerned 
about the effects on a vehicle's stability of auto- 
matic brake application, it has determined that 
a vehicle capabable of meeting specified stopping 
distance requirements when the brakes are auto- 
matically applied should not be held to the maxi- 
mum force level requirement. 

With respect to both automatic and manual 
brakes, provision is made for control of the 
parking brakes of the towed vehicle. It was 
noted by some petitioners that automatic applica- 
tion of a towing vehicle's brakes, without simul- 
taneous application of a towed vehicle's brakes, 
could lead to unstable braking and possibly to 
jackknifing. To lessen the risk of such in- 
stability, the automatic brake requirements are 
amended to require the venting of the towed 
vehicle's supply line so that its brakes will apply 
upon application of the towing vehicle's brakes. 

4. Other provisions amended. In S4 the 
definition of "antilock system" has been amended 
to refer to "rotational wheel slip" to distinguish 
the phenomenon controlled by the antilock sys- 
tems from other types of wheel slip. The defini- 
tions of "gross axle weight rating," "gross ve- 
hicle weight rating," and "unloaded vehicle 
weight" have been omitted, since they have been 
incorporated in the general definitions section of 
Part 571, 49 CFR 571.3(b). 



The equipment requirements have been 
amended in a number of minor respects. S5.1.1 
has been amended to include supply reservoir 
capacities. The reservoir capacity required has 
not been changed, but the requirement is clari- 
fied by striking the words "greater than" in 
S5.1.2.1 and in S5.2.1.1. The requirement for a 
towing vehicle protection valve (S5.1.3) has been 
amended by the use of the broader term "system" 
in place of "valve." 

The pressure gauge requirement (S5.1.4) has 
been amended to require a gauge in each service 
brake system, rather than to require a gauge di- 
rectly on the service reservoir. The warning 
signal requirement (S5.1.6) is amended in re- 
sponse to petitions to provide that warning 
must be by means other than the pressure gauge 
indicator. The antilock warning signal require- 
ment (S5.1.6), has been amended to limit the 
warning to the event of electrical failure, pend- 
ing investigation of other types of failure for 
which a warning may be practicable. 

5. Petitions denied. Several requests for 
amendment of the equipment requirements have 
been denied. A request that the service reservoirs 
be connected in series has been rejected as un- 
necessary and design restrictive. Requests for 
reduction in minimum reservoir capacity are also 
denied. The present requirement of 12 times the 
combined volume of service brake chambers has 
been applied by the SAE to intracity buses and 
school buses for some time and is considered a 
reasonable requirement for other vehicles, par- 
ticularly in the light of additional demands made 
on air capacity by antilock systems. 

Several petitions requested amendment of the 
vehicle weights specified in S5.3 for the service 
brake tests. Requests were made for additional 
weight on the vehicle in its unloaded condition 
to allow for the weight of the completed body 
and for safety equipment such as roll bars used 
during testing. Since the vehicles tested by the 
NHTSA will be completed vehicles, however, it 
is not appropriate to specify an additional 
weight. If an incomplete vehicle manufacturer 
wishes to ascertain the performance of this ve- 
hicle in one or more of its completed variations, 
he may do so by placing weights on the incom- 
plete vehicle, by actually mounting a body on 



PART 571; S 121— PRE 7 



Effactlvi: S*pt«mb«r 1, 1974 



it, or by any other means that are reasonably 
calculated to evaluate the braking performance 
of the completed vehicle. With respect to safety 
equipment, the NHTSA regards the problem of 
weight associated with safety devices as easily 
surmountable. Each of the petitons requesting 
changes in the weights specified in S5.3 is ac- 
cordingly denied. 

A number of petitions requested increases in 
the stopping distance required by S5.3.1. The 
distances specified are considered reasonable and 
well within the state of the art. Greater dis- 
tances would increase the disparity between 
trucks and cars and be contrary to the interests 
of safety. The petitions are denied. Similarly, 
the petitions for an increase in the skid number 
of the dry surface from 75 to 80 are denied. The 
75 number is representative of road surfaces, 
and has been a part of the consumer information 
requirements long enough that the availability 
of skid pads should not be a probelm. Similarly, 
the requests that 30 skid number tests be nm on 
dry pavement or that they be abandoned are 
denied. Braking in wet weather is an evident 
problem with vehicles of all types, and the 
NHTSA regards the wet-track test as an essential 
part of the standard. 

The stopping capability requirement for 
trailers (S5.3.2) was the subject of petitons re- 
questing deletion of the 90-p.s.i. pressui-e level 
requirement and objecting to the uncertainty in- 
volved in determining whether the tractor or the 
trailer is responsible if the trailer leaves the 
12-foot-wide lane. The NHTSA regards a uni- 
form service line pressure specification as an 
appropriate means of insuring uniformity in 
trailer response, even though some tractors may 
be designed to modulate air pressure in the lines. 
Since only the trailer is to be braked, the cause 
of deviation from the lane will be the trailer's 
brakes, not the tractor's. The petitions are 
denied. 

The actuation and release requirements of 
S5.3.3 and S5.3.4 were subject to a variety of ob- 
jections. One petitioner requested deletion of 
both requirements, while others requested elimi- 
nation of the 50-cubic-inch test reservoir for 
trailers that tow other trailers. On review, the 
NHTSA has decided to deny the petitions. 
Although the stopping distance test of S5.3.1 



necessarily limits the actuation time that a manu- 
facturer can allow, the additional constraint 
placed on timing by S5.3.3 has the important 
effect of producing full braking at a very early 
point during the braking maneuver where the 
speed is greatest and the effects of a reduction in 
speed most significant from the standpoint of the 
forces involved in a crash. The brake release 
time has an important bearing on the maneuver- 
ability and directional stability of vehicles in 
emergency situations. It can sometimes be as 
important for the brakes to come off quickly and 
evenly as for them to be applied quickly. 

The 50-cubic-inch test reservoir has been em- 
ployed for some time in the SAE brake testing. 
It has therefore been retained. Other sugges- 
tions in the petitions for service reservoir timing 
and for additional test component specifications 
are not adopted at this time but may be appro- 
priate subjects for future amendment. 

With respect to the loading conditions speci- 
fied in S6.1.1, a number of petitioners stated that 
the front-rear brake balance needed to achieve 
conforming performance on a truck-tractor 
loaded to GVWR in its bob-tail configuration 
would not be the best balance for that tractor 
when towing a trailer. This appears to be a 
valid objection, but the most obvious alterna- 
tive — testing with a trailer in tow — involves 
complexities that have not been fully discussed 
in the petitions. A notice is therefore being 
prepared to propose that a truck tractor be tested 
with a trailer during the stopping distance tests. 

Eifective date: September 1, 1974. Review of 
the numerous petitions for extension of the effec- 
tive date from January 1, 1973, has led to the 
conclusion that an effective date of September 1, 
1974, would permit a longer period of fleet test- 
ing to evaluate the durability of the new systems 
and that the resulting production systems are 
likely to be substantially improved by the addi- 
tional time allowed. An effective date later than 
one year from the date of issuance is therefore 
found, for good cause shown, to be in the public 
interest. 

In consideration of the above, Motor Vehicle 
Safety Standard No. 121, Air Brake Systems, in 
§ 571.21 of Title 49, Code of Federal Regulations, 
is amended to read as set forth below. This 
amendment is issued under the authority of sec- 



PART 571; S 121— PRE 8 



ElhcMva: Saptombcr 1, 1974 

tions 103 and 119 of the National Traffic and Issued on February 16, 1972. 

Motor Vehicle Safety Act, 15 U.S.C. 1392, 1407, Douglas W. Toms 

and the delegation of authority by the Secretary Administrator 

of Transportation to the National Highway 37 F.R. 3905 

Traffic Safety Administrator, 49 CFR 1.51. February 24, 1972 



PART 571; S 121— PRE 9-10 



t 



I 



k 



Effective: September 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems — Trucks, Buses and Trailers 
(Docket No. 70-17; Notice No. 4) 



The purpose of this notice is to respond to 
petitions filed pursuant to 49 CFR § 553.35, seek- 
ing reconsideration of the amendments to Motor 
Vehicle Safety Standard No. 121, Air Brake 
Systems, published February 24, 1972 (37 F.R. 
3905). The petitions are granted in part and 
denied in part. 

I. ATnendments 

S5.1.6 International Harvester stated that the 
operation of the antilock warning system should 
be the same as that of the low pressure warning 
signal under S5.1.5. S5.1.6 presently requires 
an audible warning of at least 10 seconds dura- 
tion regardless of whether the visible signal re- 
quired by the section is within the driver's 
forward field of view. The change requested by 
International Harvester would require an audible 
warning only if the visual warning is out of the 
driver's forward field of view. On reconsidera- 
tion, the NHTSA has concluded that the system 
requested by International Harvester will give 
the driver adequate warning of antilock system 
failure. S5.1.& is therefore being amended to 
parallel S5.1.5. 

S5.1.5 and S5.1.6 In a letter designated as a 
request for clarification or interpretation, General 
Motors suggested that because diesel systems do 
not have an "on" position, they might be consid- 
ered exempt from the requirement that the anti- 
lock warning signal must operate when the igni- 
tion is in the "on" position. Although the 
NHTSA does not consider it likely that the re- 
quirement will be understood as exempting 
diesels, the agency has concluded that amending 
the standard to refer to the "run" position as 
suggested by GM would avoid any possibility of 
misinterpretation. S5.1.5 and S5.1.6 are amended 
accordingly. 



55.2.1.1 Midland-Ross requested that a pres- 
sure should be specified at which the protected 
reservoir should be capable of releasing the park- 
ing brakes. On reconsideration, it seems appro- 
priate to specify a pressure that corresponds to 
the lower end of the range of pressures main- 
tained by current compressors. The section is 
therefore amended to specify a pressure of 90 
p.s.i. The related question of when the brake is 
considered to be released, also raised by Midland- 
Ross, does not require amendment. The NHTSA 
considers a brake to be released at the point 
where it no longer exerts any torque. 

55.2.1.2 In response to a question in the 
Midland-Ross petition and a related request for 
interpretation by Wagner Electric Corporation, 
this section is amended by adding the word 
"service" before "reservoir", so that the section, 
as amended, requires the total service reservoir 
volume to be at least eight times the combined 
volume of all service brake chambers at maximum 
travel of the pistons or diaphragms. The amend- 
ment reflects the basic intent of S5.2.1.2, which 
is to have a specified volume of air available to 
the service brakes. 

S5.4 Several petitioners stated that S5.4 ap- 
peared to exempt some vehicles from the dy- 
namometer requirements. This impression is 
erroneous, in that all vehicles are required to 
conform to S5.4. The source of the confusion 
appears to be the sentence in S5.4 which states 
that "[a] brake assembly that has undergone a 
road test pursuant to S5.3 need not conform to 
the requirements of this section". The intent of 
the standard is to conduct the dynamometer tests 
on new brake assemblies, and the quoted sentence 
was intended to make it clear that a single brake 
assembly would not have to pass the road test 



PART 571; S 121— PRE 11 



EffMHva: S«ptamb*r 1, 1974 



and the dynamometer test in succession. The 
sentence is being amended to clarify its meaning. 
S5.7.1.4 This section is amended in response 
to a request by Wagner Electric, to require 
manual application whenever the system pressure 
prevents automatic application. 

II. Provisions not amended 

With respect to the remaining petitions, no 
changes are being made in the standard. In 
some cases this is because the petitioner has mis- 
interpreted the applicable provisions to his dis- 
advantage and needs no amendment to obtain the 
relief he wants. In other cases, the agency has 
concluded that the requested amendments do not 
serve the need for motor vehicle safety. In one 
or two cases, the change requested may prove 
desirable but cannot be fully evaluated without 
further information. The following discussion 
deals with the petitioned requirements in numeri- 
cal order. 

S3. Clark Equipment Company requested the 
addition of trailer converter dollies to the list of 
affected vehicles. The addition is not necessary, 
in that a converter dolly is a "trailer" within the 
meaning of that term in 49 CFK 571.3(b). 

S5.1 Clark Equipment Company requested an 
amendment to exclude vacuum brake systems 
from the equipment requirements of S5.1. De- 
spite the reference to a vacuum assist in S4, the 
standard does not apply to vacuum brakes and 
therefore does not require vacuum systems to 
have the equipment described in S5.1. 

S5.1.2.2 It was suggested by Midland-Ross 
that the requirement that the reservoir must be 
capable of "withstanding" the specified pressure 
was not sufficiently precise. It may be that ex- 
perience will show a need for quantification of 
this requirement, but the agency does not con- 
sider it to be necessary at this time. A reservoir 
will be considered to withstand the test pressure 
if it shows no pressure loss during the test 
interval. 

S5.1.3 It was suggested by Midland-Ross that 
the requirements for the towing vehicle protec- 
tion system should be amended to indicate the 
degree of protection required and the operating 
modes protected. The agency's response is much 
the same as its response on S5.1.2.2: the sugges- 
tion may prove to have merit, if systems appear 



which cause problems in service. At this point, 
however, the agency will retain the broad re- 
quirement that a towing vehicle must have a 
system to protect it from the loss of air pressure 
in the towed vehicle, without regard to the sys- 
tem's design or method of operation. 

55.1.5 Midland-Ross requested an increased 
pressure level at which the low pressure warning 
signal actuates, so that it would be above the 
protection valve trip pressure used in new trail- 
ers. The requested change is not necessary, in 
that the standard does not now prevent the 
manufacturer from setting the signal actuation 
level at a pressure above 60 p.s.i. If Midland- 
Ross wishes to set its level at 80 p.s.i., it may 
do so. 

55.1.6 Clark Equipment Company requested 
that the antilock warning signal requirements be 
expanded to apply to the failure of a towed 
vehicle's antilock system. The NHTSA is re- 
ceptive to further discussion of this issue. How- 
ever, it has decided not to adopt the request at 
this time. Trailers are not required to have 
provision for antilock warning systems, and re- 
quiring towing vehicles to accommodate systems 
that are not likely to exist would be unjustified. 

S5.3.1 Two petitioners requested amendments 
of the stopping distance requirements. The 
Carlisle Corporation requested a longer stopping 
distance, and Midland-Ross requested that the 
reference to "controlled lockup" be amended to 
specify a system that would provide for resump- 
tion of wheel rotation at some point before the 
speed falls to 10 m.p.h. Both requests are denied. 
The distances specified are considered to be ap- 
propriate and within the current state of the art. 
The requested change with respect to wheel 
lockup would permit systems in which all wheels 
could be completely locked for substantial periods, 
a situation that S5.3.1 was designed to avoid. 

S5.3.3 Midland-Ross requested that Figure 1, 
referenced by this section, should be amended by 
specifying a pressure of 100 p.s.i. in both reser- 
voirs, by omitting the tractor protection valve 
from the test rig, and by employing a service 
brake control valve rather than a brake pedal. 
Because S5.3.3 specifies a pressure of 100 p.s.i., 
it should be clear that each reservoir would be at 
that pressure, and no amendment is necessary. 



PART 571; S 121— PRE 12 



Effectiva: Seplembar 1, 1974 



A protection valve is used because such valves 
are in widespread use, even though they are not 
required by the standard. The service brake 
pedal specified in Figure 1 is a service brake foot 
control valve. No change of label appears 
necessary. 

55.4.1 International Harvester requested the 
deletion of this section as unnecessary. As stated 
before, the purpose of the section is to promote 
compatibility between the brakes of vehicles used 
in combination. The agency is of the opinion 
that it serves the stated function and has there- 
fore retained it. 

55.4.2 Wagner Electric and the Carlisle Cor- 
poration each objected to certain aspects of this 
section. Wagner Electric requested the reinstate- 
ment of the phrase "at least" before the decelera- 
tion of 9 f.p.s.p.s., and requested the use of the 
phrase "a minimum" in S5.4.2.1, on the grounds 
that it is impossible to achieve a deceleration rate 
of exactly 9 f.p.s.p.s. In response, it should be 
pointed out that it is not necessary for a manu- 
facturer to conduct his tests at exactly the speci- 
fied rate, but only to test in such a manner as to 
assure himself that if the brakes were to be tested 
at that rate they would meet the requirements. 
It is to his advantage to test under less favorable 
conditions than those specified in the standard. 
The insertion of the language requested by Wag- 
ner would, if anything, make the test more severe 
for the manufacturers, in that the government 
could run tests with average decelerations in ex- 
cess of 9 f.p.s.p.s. making the "worst case" situa- 
tion much more difficult to ascertain. 

The Carlisle Corporation objected to proce- 
dural disparities between the retardation force 
tests of S5.4.1 and the brake power tests of 
S5.4.2. The basic procedural difference between 
the sections is that the measurement period under 
55.4.1 begins when the specified air pressure is 
reached whereas the period under S5.4.2 begins 
with the onset of deceleration. Although it may 
be that different instrumentation will be required 
in the two tests, they are not for that reason 
inconsistent or incompatible. The NHTSA con- 
siders each procedure to be appropriate for the 
aspect of performance that it measures. 

S5.4.3 The Carlisle Corporation requested a 
further reduction in the lower limit of the re- 



covery force, from the current level of 20 p.s.i. 
to 10 p.s.i. The NHTSA considers a brake sys- 
tem that produces a deceleration of 12 f.p.s.p.s. 
with a pressure of only 10 p.s.i. to be too sensi- 
tive and therefore denies the petition. 

S5.5.2 Clark Equipment Company objected to 
the use of the stop lamp circuit to power the 
antilock system. The basis for the requirement 
is the need for compatibility between trucks and 
trailers made by different manufacturers. The 
stop lamp circuit is the most suitable electrical 
coimection between trucks and trailers because 
it is always energized when the brakes are ap- 
plied. It was therefore chosen as the source of 
jx)wer. The agency is of the opinion that the 
stop lamp circuit has adequate power for single 
trailer applications. For multiple trailers, it may 
be necessary to employ complementary systems 
as permitted by S5.5.2. The petition is therefore 
denied. 

55.6.1 In response to n request for interpreta- 
tion by International Harvester, the intent of 
this section is to require parking brakes on each 
axle other than steerable front axles. 

55.6.2 Midland-Ross suggested the amendment 
of this section to specify that a sliding bogie on 
a semitrailer shall be placed in its most favorable 
position. As presently worded, the section is 
silent with respect to bogies so that the NHTSA 
will be obliged to test in a manner that favors 
the manufacturer. However, if there are indica- 
tions that the position of the bogie makes a 
substantial difference in the braking performance 
of the vehicle, the agency will consider rule- 
making to specify that the trailer must meet the 
requirements with the bogie in any position. 

S5.7.1.1 Wagner Electric requested an amend- 
ment to provide for brake application when the 
pressure in "any" service reservoir is less than 
the automatic application pressure level. The 
section now requires application when "all" serv- 
ice reservoirs are below that level. The NHTSA 
does not consider the requested amendment neces- 
sary to permit the type of system that Wagner 
envisions. It is permissible under the present 
wording for a manufacturer to have a system 
that applies the brakes upon a low pressure sig- 
nal from a single reservoir. To require operation 
in such a case, as Wagner requests, would elimi- 



PART 571; S 121— PRE 13 



EffMMva: Scpfambcr 1, 1974 



nate systems that are capable of fully applying 
the service brakes despite low pressure in one 
reservoir. 

S5.7.2.2 The Clark Equipment Company re- 
quested deletion of "brake fluid housing" from 
the list of items whose failure must not affect the 
parking brake system. The purpose of the sec- 
tion is to make it clear that the sharing of com- 
ponents by the service and emergency braking 
systems should not be construed as permitting 
malfimction of the parking brake system despite 
the provisions of S5.6.3. The petition is denied. 

S5.8 The Clark Equipment Company requested 
the deletion of the phrase "or S5.6.2" from this 
section, on the grounds that it converts the re- 
quirement into a parking brake requirement that 
may be weaker than the emergency braking per- 
formance currently required under the regula- 
tions of the Bureau of Motor Carrier Safety. 
However, despite the use of .20 rather than the 
value of .28 specified in S5.6.1, the trailer under 
S5.6.2 is loaded to its GVWR and the supporting 
dolly is unbraked so that the braking perform- 
ance required by the two sections is nearly iden- 
tical. The NHTSA has therefore decided to 
retain the option of S5.6.2 under S5.8. 

S6.1.1 Midland-Ross requested that the loading 
of a trailer be based on the sum of its GAWR's 
rather than on its GVWR. A GVWR designa- 
tion for trailers is required by Part 567, and the 
agency considers it appropriate to specify GVWR 
as the test condition imder this section. 

S6.1.7 International Harvester again ques- 
tioned the appropriateness of using a skid number 
of 75 for road tests. This issue has been raised 



a niunber of times in the course of the various 
braking standard rulemakings. Although the 
NHTSA is not prepared at this time to state 
that a number higher than 75 ought to be se- 
lected, the agency intends to collect additional 
data concerning road surfaces with a view to 
possible future changes. 

S6.1.9 Midland-Ross stated that parking brake 
tests for semitrailers should be conducted with 
the trailer front end supported by the trailer 
landing gear. The use of the parking brakes as 
part of the emergency braking system and the 
unknown effect of the friction in the landing 
gear system weigh against the adoption of this 
requirement. The petition is denied. 

S6.2.1 The Carlisle Corporation requested 
that a 5% tolerance be specified in the dyna- 
mometer loading. The request is denied, for the 
reasons given in the preceding discussion of 
Wagner Electric's petition on S5.4.2. 

In consideration of the foregoing, Motor Ve- 
hicle Safety Standard No. 121, 49 CFR § 571.121 
is amended .... 

Effective date: September 1, 1974. 

This rule is issued imder the authority of sec- 
tions 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act, 15 U.S.C. 1392, 1407, 
and the delegation of authority at 49 CFR 1.51. 

Issued on June 21, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 12495 
June 24, 1972 



PART 571; S 121— PRE 14 



Effacliv*: September 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 

(Docket No. 73-13; Notice 3) 



This notice amends Motor Vehicle Safety 
Standard No. 121, Air brake systems, by modify- 
ing the emergency stopping distance require- 
ments for truck-tractors, the parking brake re- 
quirements for trailer converter dollies, and the 
recovery requirements for antilock equipped 
brakes, and by establishing a new test condition 
for loaded truck-tractors, special test conditions 
for certain drive and axle configurations, and a 
new burnish condition for road tests. 

The amendments adopted by this notice repre- 
sent a partial adoption of the changes proposed 
in Docket No. 73-13, Notice 1 (38 F.R. 14963; 
June 7, 1973). The comments to the proposal 
were divided as to the merits of most of the 
changes proposed. Running throughout the 
comments, however, was an overriding concern 
with lead time. Although a manufacturer might 
favor a change, such as the proposed change in 
the burnish condition, he may find himself un- 
able to adjust to it within the time remaining 
before the standard becomes effective on Septem- 
ber 1, 1974. The NHTSA, for its part, does not 
consider the proposed changes significant enough 
to warrant postponing the effective date of the 
standard. The agency has therefore adopted two 
provisions for which lead time appears to be a 
problem — the new burnish condition and the new 
truck-tractor test condition — as options for the 
period between September 1, 1974, and Septem- 
ber 1, 1976. Of the remaining changes proposed 
in Docket 73-13, some are adopted effective 
September 1, 1974, others are not being adopted 
and will not be further considered for adoption, 
and others remain as candidates for adoption. 
If the latter are adopted, they will become effec- 
tive at some date beyond September 1, 1974. 
The treatment accorded each of the proposed 
changes is set out in order below. 



S4. Definitions were proposed for "isolated 
reservoir" and "service reservoir". Insofar as 
the principal use of these definitions was to be 
in proposed amendmMits which are not being 
adopted at this time, there is little purpose in 
adding them to S4 at this time. They are there- 
fore not adopted. 

S5. 1.2.5 This new section was to have been 
added to prevent the diversion of air from the 
service reservoirs into other reservoirs when the 
service reservoir pressure is below 60 psi. In 
addition to questions of lead time, several com- 
ments stated that the equipment served by 
auxiliary reservoirs, such as windshield wipers, 
often plays a role in safety as significant as that 
of the brake system. In consideration of these 
factors, the section is not being adopted at this 
time, and if subsequently adopted will take into 
account both lead time and the effects on other 
safety systems. 

S5.1.3 The amendment proposed to the towing 
vehicle protection system requirements was to 
have accompanied the amended emergency brak- 
ing requirements of S5.7, and would have desig- 
nated the protection system as the system 
enabling the vehicle to meet the emergency stop- 
ping requirements of S5.7.2.2 and S5.7.2.3. The 
agency has decided to defer action on the amend- 
ments to S5.7, as discussed below, and accord- 
ingly takes no final action on S5.1.3 at this time. 

S5.1.6 An amendment was proposed to the 
antilock failure signal requirements in response 
to a petition by Berg Manufacturing Company. 
Berg has subsequently withdrawn its petition, 
and in the absence of compelling reasons to adopt 
the proposed change, the NHTSA has decided 
not to amend S5.1.6. 



PART 571; S 121— PRE 15 



Effective: September 1, 1974 



S5.2.1.1 The requirement for the reservoir 
used to release the parking brakes was to be 
amended to specify two brake releases, rather 
than one, and to specify the initial pressure from 
which these releases were to be accomplished. 
The agency continues to regard these changes 
favorably, but has decided to defer final action 
until the issuance of amendments concerning the 
parking and emergency systems, as discussed 
under sections S5.6 and S5.7. 

S5.3.1 and S5.3.2. Rather than amend the 
general language of these sections concerning the 
circumstances under which lockup is permitted 
during a stop, the agency has decided to leave 
the sections essentially unaltered. In response 
to requests to clarify the treatment accorded 
liftable axles, the section is amended to permit, 
in effect, liftable axles without antilock on ve- 
hicles with more than two nonsteerable axles. 
Liftable axles on vehicles with two nonsteerable 
axles would continue to be subject to the no- 
lockup requirement except for controlled lockup 
allowed by an antilock system. 

The principal change proposed for S5.3.1 and 
S5.3.2 had been a change in the description of 
permissible lockup from "controlled lockup al- 
lowed by an antilock system" to "lockup of 
wheels controlled by an antilock system that does 
not permit more than half the wheels on any 
controlled axle to lock more than momentarily." 
The intent of the proposed revision was to fore- 
stall systems whose "control" over the lockup of 
wheels, although nominally within the meaning 
of the language, might be so marginal as to per- 
mit more than half the wheels on a tandem axle 
to lock throughout the duration of a stop. The 
proposed amendment, however, was read by some 
manufacturers as expressly permitting systems 
in which half the wheels on each axle would not 
be sensed or monitored by the antilock controller 
or cycled by the antilock system. Such was not 
the intent of the proposal. It appears, on fur- 
ther review, that such systems are not currently 
in prospect. The agency has concluded that the 
better course is not to amend the "controlled 
lockup" language at this time, but to observe 
developments in the industry, with a view toward 
amending the requirements if subsequent events 
indicate a safety need. 



S5.3.4 The notice had proposed increasing the 
release time for trailers from 0.50 second to 0.60 
second. In the face of several objections to the 
proposal on the grounds that it ran counter to 
the need for coordination of braking between 
vehicles in combination, and on the basis of in- 
formation indicating that the timing problem is 
solvable for trailers, the proposal is being with- 
drawn. 

S5.4.1 The notice had proposed deleting the 
retardation force requirement, leaving it ap- 
plicable only to towed vehicles. The change had 
been proposed as a result of the proposed amend- 
ment to the tractor test conditions whereby the 
tractor would be tested with a trailer. In the 
light of the comments, and of the continuance 
of the current tractor test conditions as an op- 
tion, the NHTSA has decided not to adopt the 
proposed change. 

S5.4.3 The notice proposed to delete the mini- 
mum recovery pressure requirement for brakes 
equipped with antilock systems, leaving the 20 
psi minimum force level for other brakes. Upon 
further consideration, the agency has concluded 
that a minimum recovery force requirement 
should be retained for antilock equipped brakes, 
but at a level below 20 psi. The agency has 
determined that 12 psi is a minimum level that 
permits a greater variety of brake linings while 
retaining a residual protection against over- 
sensitive brakes in the event of antilock failure. 
Accordingly, the agency adopts 12 psi as the 
minimum recovery force for antilocked brakes. 

S5.6 The parking brake requirements of S5.6 
had been one of the principal areas affected by 
the proposal. In addition to changes in the 
parking brake application requirements and de- 
letion of the optional static pull test for parking 
brake holding ability, the notice had proposed 
new requirements for parking brake stopping 
capability. This latter proposal received almost 
unanimous criticism. Although the agency has 
not concluded that the proposal is without merit, 
the issues raised by the comments and the evident 
lead time problems associated with the proposal 
have led the agency to conclude that no further 
action should be taken without additional notice 
and opportunity for comment and that the ef- 
fective date for any such requirement should lie 
beyond September 1, 1974. 



PART 571; S 121— PRE 16 



Effcctiv*: S*pltmbtr 1, 1974 



Of the remaining changes to S5.6 proposed by 
the notice, only the exemption of converter 
dollies from the parking brake requirements is 
being adopted at this time. The proposed dele- 
tion of the optional static pull test of S5.6.2 has 
not been carried out, and the options of S5.6.1 
and S5.6.2 will be retained. The proposed park- 
ing brake application requirements of S5.6.6 and 
S5.6.7, which had reflected amendments proposed 
to the emergency braking requirements of S5.7 
are not being adopted at this time, pending fur- 
ther rulemaking on S5.7. 

S5.7 The notice had proposed substantial re- 
visions to the emergency braking requirements 
of S5.7, principally in response to a petition by 
ATA and to an earlier petition by Ford. The 
majority of the changes proposed in response to 
the ATA petition continue to be viewed favor- 
ably by the NHTSA. However, review of the 
comments suggests both that further refinements 
are necessary and that the proposed changes will 
require additional time for implementation. The 
agency is therefore deferring final rulemaking 
action on the aspects of S5.7 addressed by the 
ATA to a later date and will issue such changes 
as it may decide upon with an effective date 
beyond September 1, 1974. 

Amendinents to the emergency stopping dis- 
tance requirements, presently contained in 
S5.7.2.3 of the standard, were proposed by two 
successive notices. In Docket 73-4, Notice 1 (38 
F.R. 6831), the agency proposed a favorable re- 
sponse to a petition by Ford concerning the 
emergency stopping distances for short-wheelbase 
two-axle truck-tractors in the unloaded condi- 
tion. When tested in this weight condition, 
truck-tractors are driven without a trailer — a 
condition in which they are seldom operated over 
the road. The effect of the proposed amendment 
would have been to permit a limited number of 
truck-tractors equipped with modulated emer- 
gency braking systems to stop in a somewhat 
longer distance than that permitted other ve- 
hicles with modulated emergency braking. 

Comments to Docket 73-4 indicated that there 
were other vehicles whose braking systems were 
complicated by the shorter emergency stopping 
distance. In response to these comments, the 
agency proposed in Docket No. 73-13, Notice 1, 
to apply the longer stopping distances to other 



vehicles in the imloaded condition provided they 
were capable of stopping within the shorter dis- 
tance with the assistance of the parking brakes. 
The comments to Docket No. 73-13 objected to 
the use of the parking brake in this fashion, and 
some asserted that if the longer distance were 
appropriate for some vehicles it should be ap- 
propriate for all. Upon review of the comments, 
the agency has decided against a general length- 
ening of emergency stopping distances. Upon 
weighing the rarity of truck-tractor operation 
without a trailer against the potential costs of 
modifying truck-tractors to meet the shorter 
stopping distance in that configuration, however, 
the agency has concluded that the longer stop- 
ping distances specified in Column 4 of Table II 
should be applicable to truck-tractors, regardless 
of weight distribution or number of axles, but 
that other vehicles should continue to meet the 
emergency stopping distances of Column 3 of 
Table II. Section S5.7.2.3 is amended accord- 
ingly. 

S5.8 The notice had proposed to transfer the 
emergency braking capability requirement for 
trailers from S5.8 to S5.6.7. Until such time as 
the agency decides to adopt S5.6.7, S5.8 will be 
retained. To provide emergency capability for 
converter dollies, in the absence of mandatory 
parking brakes for them, the NHTSA has 
amended the section to provide for application 
of the dolly's service brakes in the event of com- 
plete air pressure loss in the control lines. This 
system is presently installed in virtually all 
dollies, as a result of regulations issued by the 
Bureau of Motor Carrier Safety (49 CFR 393.43) 
and is considered to be a practicable substitute 
for the parking brakes in emergency situations. 

S6.1 A number of revisions to the test condi- 
tions of S6.1 were proposed. These revisions 
are adopted in substance, with some changes in 
structure and in section numbering. The new 
truck-tractor test condition, whose insertion as 
S6.1.2 had caused confusion as to the fate of the 
old S6.1.2, has been adopted as S6.1.10, thereby 
leaving the current sections S6.1.2 to S6.1.9 with 
their present numbering. 

S6.1.8 The road test burnish procedures pro- 
posed in the notice are being adopted as an op- 
tional procedure for the period September 1. 
1974, to September 1, 1976. After September 1, 



PART 571; S 121— PRE 17 



Effective: September 1, 1974 



1976, the new burnish procedure will replace the 
older procedure as the only burnish prescribed 
for road tests. This two-step arrangement ap- 
pears necessary to permit manufacturers whose 
testing to date has been conducted with the cur- 
rent burnish procedure, and who need additional 
time, to phase in the new procedure. 

S6.1.10 A similar phase-in has been found 
necessary for the new tractor test conditions. 
Several manufacturers had stated that their 
evaluation programs had been conducted without 
trailers and that retesting would be necessary in 
order to certify their vehicles under the new 
conditions. The new conditions are therefore 
adopted as an option for the period September 1, 
1974, to September 1, 1976. During this period 
a manufacturer may choose to test his vehicles 
under either loading condition, and such tests as 
the NHTSA conducts will be in the loading 
condition chosen by the manufacturer for the 
vehicle under test. 

56. 1.10.1 The control trailer to be used under 
S6.1.10 is specified as conforming to Standard 
No. 121. 

56.1.10.2 The center of gravity of the loaded 
trailer is specified as being at a height of 66 ±3 
inches above the ground. There was a variety 
of opinion in the comments as to how high the 
center of gravity should be, but upon reviewing 
the comments the agency has concluded that the 
66±3 inch range originally proposed is reason- 
ably representative of loading conditions. Axle 
load shift due to the rake angle of the trailer bed 
does not appear to be a problem in that each 
axle of the trailer is loaded to its GAWR when 
the trailer is connected to the tractor. 

56. 1.10.3 and S6. 1.10.4 In response to com- 
ments suggesting that the lengths and weight 
ratings of the trailers specified in the proposal 
were not those in most general use, the agency 
has increased the length of the trailer specified 
in S6.1.10.3, reduced the length of the trailer 
specified in S6.1.10.4, and lowered the gross axle 
weight rating for each trailer. 

S6. 1.10.5 The loading condition of the trailer 
for tests of the tractor's brakes is substantially 
the same as that proposed in the notice. The 
tractor's fifth wheel does not have to be adjust- 
able, as some comments inferred, but if it hap- 



pens to be adjustable it must be adjusted to 
produce the specified weight distribution. The 
axle loads are to be measured at the tire-ground 
interfaces, in response to comments that the for- 
mer reference to the "force transmitted to the 
tractor axles through the kingpin" was not clear 
as to the method of measurement. 

S6. 1.1 0.6 and S6.1.10.7 These sections are de- 
signed to establish performance specifications for 
the trailers to be used for truck-tractor testing. 
They are not intended as performance require- 
ments for trailers, but only as test equipment 
specifications for the tractor tests. The trailer 
loading condition specified is somewhat different 
from that used in testing the performance of the 
tractor, because the tests are aimed at isolating 
the performance of the trailer brakes. The lo- 
cation of the fifth wheel is specified as the posi- 
tion determined under S6.1.10.5, but the trailer 
is loaded so that its axle is at its gross axle 
weight rating and its kingpin is at unloaded 
weight. 

The actuation and release times specified for 
the trailer in the evaluation tests were questioned 
by several comments. It may be necessary, in 
some cases, for a special valve to be installed on 
the tractor if the tractor's system is too slow to 
actuate the trailer's brakes in the time specified. 
The purpose of the timing specification is simply 
to remove the tractor's performance as a factor 
in the trailer brake evaluation. AVhen the trailer 
is used in tests of a tractor pursuant to S5.3.1 it 
will, of course, be connected to the tractor's nor- 
mal control system. 

In addition to specifying the same loading in 
S6.1.10.7 as in S6.1.10.6, the ratio applied to 
determine the trailer's stopping distance under 
S6.1.10.7 has also been revised to conform to that 
used in S6. 1.10.6. To accommodate tractors that 
are not capable of 60-mph speeds, each section 
now specifies that the trailer is tested at the 
speed at which the tractor for which it will be 
used is tested. 

S6.1.11 and S6.1.12 These sections relate to 
special drive conditions and the position of lift- 
able axles, and are adopted as proposed. 

S6.1.13 This new section was proposed to es- 
tablish performance requirements for the trailer 
timing test rig specified in Figure 1. In the 



PART 571; S 121— PRE 18 



light of objections in the comments to the per- 
formance levels specified, the agency is deferring 
final rulemaking at this time and will issue such 
clianges as it may decide upon with an effective 
date beyond September 1, 1974. 

The tables and figures proposed for adoption 
or amendment by the notice are adopted as pro- 
posed, except for the omission of the parking 
brake dynamic test from Table I. 

In consideration of the foregoing, Motor Ve- 
hicle Safety Standard No. 121, Air brake sys- 
tems (49 CFR 571.121), is amended .... 



EffKtIv*: S«pt«mb*r 1, 1974 

Effective date: September 1, 1974. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718, 
15 U.S.C. 1392, 1407; delegation of authority at 
49 CFR 1.51.) 



Issued on December 20, 1973. 



James B. Gregory 
Administrator 

39 F.R. 804 
January 3, 1974 



PART 571; S 121— PRE 19-20 



Effective: September 1, 1974 
March 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 2) 



This notice amends Standard No. 121, A/r 
brake systems, 49 CFR 571.121, in response to 
several petitions for reconsideration of amend- 
ments to the standard published January 3, 1974 
(39 F.R. 804), and after consideration of com- 
ments on a proposal published March 1, 1974 
(39 F.R. 7966). A notice of proposed rulemak- 
ing has been issued separately to propose modi- 
fication of the standard as it applies to trailers. 

Reconsideration of Amendments — 73-13; Notice 3 
The amendments under reconsideration concern 
emergency stopping distance requirements for 
truck tractors, parking brake requirements for 
trailer converter dollies, recovery requirements 
for antilock-equipped brakes, a new test condition 
for loaded truck-tractors, special test conditions 
for certain drive and axle configuration, and a 
new burnish condition for road tests. Several 
manufacturers commented on issues which lie 
beyond the scope of those amendments and are 
therefore inappropriate for treatment in this re- 
sponse. Wagner Electric and Midland-Ross' 
petitions to amend S5.1.2.1 and S5.2.1.2 (Midland 
also petitioned on S5.1.2.2 and S5.2.1.3) and 
AVagner's petition to modify Table III retarda- 
tion values will therefore be considered as peti- 
tions for new rulemaking to be answered in a 
separate notice. 

The American Trucking Association (ATA) 
requested reconsideration of NHTSA's decision 
to permit either automatic or modulated emer- 
gency brake systems as options while further 
consideration of the modulated system takes 
place. As sUted in Notice 3, the NHTSA has 
concluded that some aspects of the system may 
need refinement and that all vehicle manufactur- 
ers cannot in any case make all their vehicles 
conform to modulated brake system requirements 



by the standard's effective date. Accordingly, 
while the majority of the changes proposed in 
response to the ATA petition continue to be 
viewed favorably, for the present ATA's petition 
is denied. 

Wagner Electric and General Motors objected 
to the retention of brake retardation force re- 
quirements for towing vehicles as redundant in 
view of the stopping distance requirements which 
also apply to them. The NHTSA proposed de- 
letion of these dynamometer requirements pre- 
viously and, having considered the latest sub- 
missions and information, hereby amends S5.4.1 
to delete towing vehicles from the standard's 
requirements. The NHTSA has tentatively con- 
cluded that the stopping distance requirements 
can establish satisfactory brake balance between 
towed and towing vehicles, and that the cost of 
dynamometer testing is not justified by corre- 
sponding safety benefits. It should be noted that 
the dynamometer test may be reinstituted if ex- 
perience demonstrates its need. 

Fruehauf, in a late submission to this docket 
and in other docket comments, has emphasized 
the importance to lateral stability of a slower 
release time for trailers. A 0.60-sec maximum 
release time proposed in Notice 1 was not acted 
on in Notice 3 in the belief that it ran counter to 
the need for coordination of braking between 
vehicles in combination, but further study has 
persuaded this agency that a slightly slower re- 
lease time for trailers is not detrimental to safe 
operation of combination vehicles. S5.3.4 has 
been amended accordingly. 

General Motors and the Motor Vehicle Manu- 
facturers Association (MVMA) petitioned for 
deletion of the 12 Ib/in^ minimum pressure re- 
quirement for brakes controlled by an antilock 



PART 571; S 121— PRE 21 



Effaclive: September 1, 1974 
March I, 1975 



system. The purpose of the minimum pressure 
is to eliminate oversensitive brakes because of 
the difficulty in modulating them. The lower 
value was established for antilock-controlled 
brakes on the assumption that a functioning 
antilock would normally compensate for over- 
eensitivity. A residual value was retained in the 
event of antilock failure, not to compensate for 
driver surprise, as assumed by the MVMA, but 
rather to aid the driver in his efforts to carefully 
modulate a sensitive brake. The NHTSA has 
seen no evidence to support the assertions made 
by MVMA that this requirement could down- 
grade stopping performance. Except for Gen- 
eral Motors' request to clarify antilock "control" 
in this section, the petitions to amend S5.4.3 are 
accordingly denied. S5.4.3 is modified to substi- 
tute "subject to the control of" in place of "con- 
trolled" to make clear that the antilock need not 
be activated. 

General Motors and the MVMA objected to 
the test condition where a vehicle "is loaded to 
its gross vehicle weight rating, distributed pro- 
portionately to its gross axle weight ratings", 
arguing that this distribution formula could lead 
to overload of one or more axles. The General 
Motors illustration indicates a misunderstanding 
of the section's wording. The phrase "is loaded 
to its gross vehicle weight rating" describes a 
weight condition, that of the fully loaded vehicle, 
and the provision requires that this weight be 
distributed in proportion to the gross axle weight 
ratings. General Motors and the MVMA appar- 
ently interpreted the phrase to describe only that 
portion of the gross vehicle weight rating which 
"is loaded" on an unloaded truck to bring its 
weight up to GV^VR. The condition states that 
what is distributed proportionately is the gross 
vehicle weight rating (i.e. the weight of the 
loaded vehicle), and not just that portion of the 
rating that constitutes the "load." There is no 
mathematical possibility of overloading an axle 
under this condition, since the GV^VR must be 
no more than the sum of the GAWR's. 

Ford stated with respect to S6.1.10.5 that "on 
some vehicles, it may not be possible to adjust 
the fifth wheel to a position in which the tractor 
can be loaded to GVIVR without exceeding the 
GAWR of one axle." It may be that Ford's 
problem arises from the same misunderstanding 



described above with respect to GM and MVMA. 
To the extent, however, that the Ford petition 
implies that a manufacturer can establish a 
GWVR for a truck tractor which can not be 
attained without axle overload, the petition is 
based on a misconception of GVWR and is there- 
fore denied. 

Wagner Electric requested that the loadings 
in S6.1.10.6 be made uniform with S6.1.10.5 and 
S6.1.10.7. These loadings are not intended to be 
uniform, however, because the first condition 
specifies loading for purposes of truck-tractor 
testing, while the latter two conditions only es- 
tablish test equipment specifications for the 
"control trailer test device" which is used in 
testing the truck-tractor. S6.1.10.6 and S6.1.10.7 
loadings differ so that the service brake and 
emergency brake capabilities of the control trailer 
are separately designed to place greater demands 
on the truck tractor's service braking system than 
its emergency braking system. The calculations 
are based on an evaluation of the capacity of the 
brakes that are expected to be placed on produc- 
tion trailers in accordance with the dynamometer 
test requirements. 

For the benefit of manufacturers who mistak- 
enly consider these test conditions to be minimum 
performance requirements, it should be empha- 
sized that the S6.1.10.6 and S6.1.10.7 values are 
conditions, i.e., characteristics of the control 
trailer test device which must be duplicated as 
closely as possible for testing. As with any other 
test device characteristic, to the degree that the 
control trailer can not produce exactly the right 
stopping distance, the certifying manufacturer 
should ascertain conformity of his vehicles under 
slightly more adverse conditions than those 
specified, in this case by slightly reducing the 
trailer brakes' capacity (to stop in the specified 
distance). 

General Motors objected that the lighter con- 
trol trailer capacities (18,000 and 32,000 pounds 
in place of 20,000 and 40,000 pounds) specified 
in the amendment would lower control trailer 
performance and thereby increase the perform- 
ance required of truck tractors. The change was 
made to specify commonly used trailers, to aid 
manufacturers in meeting the September 1, 1974, 
effective date. The NHTSA continues to con- 
sider the increased availability of test devices to 



PART 571; S 121— PRE 22 



Effective: September 1, 1974 
March 1, 1975 



be more significant to promulgation of a fully 
satisfactory final rule than the small quantitative 
change noted by General Motors, and their peti- 
tion is therefore denied. 

General Motors and the MVMA requested 
specification of test load density to resolve diffi- 
culties in establishment of the "worst case" center 
of gravity height when testing trucks. Specifi- 
cation of a test load density, however, is unneces- 
sary. The manufacturer of a truck or incomplete 
vehicle should establish the limits of placement 
of the load center of gravity as a part of his 
design considerations, to be specified in the Part 
568 document for an incomplete vehicle or in his 
instructions to users in the case of a completed 
one. This establishes an envelope within which 
the vehicle is certified to comply with Standard 
121 under full load. Once that envelope is estab- 
lished, the appropriate load densities to test the 
vehicle's conformity can be derived from it. 

Several petitions were received with regard to 
brake burnish procedures. The M"\rMA and 
Ford requested reinclusion of language found in 
the proposal that specified an acceleration pro- 
cedure for vehicles unable to reach the specified 
speed in one mile. General Motors submitted 
minor changes of an editorial nature and new 
language to specify an increased deceleration rate 
for vehicles unable to reach the specified speed 
in one mile. The NHTSA has concluded that 
language which appeared in the proposal and 
reflects current SAE procedure should be adopted. 
The General Motors increased deceleration 
method represents a new procedure which has not 
been evaluated by the NHTSA or proposed in 
any previous rulemaking. The suggestion of 50 
snubs before allowing a cooling period is also a 
new General Motors proposal which the NHTSA 
has not had the opportunity to evaluate. With 
the exception of one recommendation, General 
Motors' editorial suggestions are adopted to be 
consistent with the titles in Table IV. The word 
"maximum" was deleted from S6.1.8.1 at the re- 
quest of several manufacturers because it was 
inappropriate to the specification of temperature 
range. 

Ford requested the addition of a burnish pro- 
cedure for parking brakes which do not utilize 
the service brake components. Language has 



been added to specify a burnish procedure for 
these brakes in accordance with the manufactur- 
er's recommendations. 

Two other issues were raised with regard to 
the road test conditions. To answer Wagner 
Electric's petition for clarification of S6.1.10.7, 
the "valve controlling the trailer brakes" may or 
may not be part of the normal commercial system 
of the tractor depending on whether or not the 
normal system can provide the timing specified. 
The purpose of standardizing timing specifica- 
tions is simply to remove the tractor's perform- 
ance as a factor in the test trailer brake evalua- 
tion. 'WTien the trailer is used in tests of a 
tractor pursuant to S5.3.1, it will, of course, be 
connected to the tractor's normal control system. 

Greneral Motors questioned the safety benefit 
of wheel lockup requirements for liftable axles 
on buses equipped with two non-steerable axles 
if other axles other than the liftable axle can 
themselves meet the stopping distance require- 
ments. The agency considers the controlled per- 
formance of the liftable axle to be of considerable 
benefit for added stability under braking condi- 
tions other than straight ahead braking required 
by the standard, and on this basis it denies the 
GM petition. 

In other areas of the standard. General Motors 
petitioned for longer emergency stopping dis- 
tances for all vehicles, reasoning that an excep- 
tion to the values for truck-tractors in an 
unloaded condition (based on rarity of opera- 
tion) could be as easily justified for the rare 
emergency stop situation of any vehicle. The 
rationale ignores the fact that the emergency 
values were established in the first place with the 
rarity of such occurrences in mind, and that the 
exception is posited on the combined rarity of 
unladen truck-tractor operation involved in an 
emergency situation. The problem of testing 
chassis-cabs can be met by specifying conformity 
to S5.7.2.3 with a specified weight on the rear 
axle representing the vehicle body weight. Gen- 
eral Motors' petition to apply column i values 
to all vehicle emergency stopping distance re- 
quirements is therefore denied. 

Wagner Electric petitioned to modify the 
wording of S5.8 concerning emergency applica- 
tion of trailer converter dolly ser\ice brakes so 



PART 571; S 121— PRE 23 



Effscllve: September 1, 19/4 
March 1, 1975 



that the wording would be identical to Bureau 
of Motor Carrier Safety regulations (49 CFR 
393.43). Wagner's proposed wording, however, 
applies to towing vehicle performance, where the 
triggering signal is a low, fixed air pressure, and 
the wording would not be appropriate for trailer 
performance, where the triggering signal is a 
venting of the supply line to the atmosphere. 
The So. 8 language is actually compatible with 
§ 393.43(b), in that BMCS calls for towing ve- 
hicles to have an automatic means of activating 
the emergency features of the trailer air brakes, 
and S5.8 calls for compatible automatic features 
on the trailers. Wagner's petition is therefore 
denied. 

General Motors asked whether the S5.4 require- 
ment that brake assemblies meet tests in sequence 
actually exempts some brakes from all three tests 
if they are elsewhere exempted from the first. 
Paragraph So.4 does not exempt any brake as- 
semblies from any requirement. The brakes on 
a vehicle which does not have to comply with 
S5.4.1 must comply with S5.4.2 and S5.4.3. 

Several comments requested correction of the 
omission of the words "in the service brake 
system" from S5.7.2.3 as published in Xotice 3. 
The omission was inadvertent and has been 
corrected. 

Greneral Motors requested an indication that 
stopping sequence steps 2 and 3 in Table I apply 
only to truck-tractors. The steps have been 
changed to indicate that these steps apply only 
to truck-tractor testing by means of a control 
trailer. As for the objection that S6.1.10.7 im- 
plies the emergency system of a truck-tractor 
must control the trailer spring brakes, S6.1.10.7 
has been clarified by the addition of a qualifying 
phrase. S6.1.10.6 and S6.1.10.7 have been further 
clarified by adding headings to indicate that they 
are test equipment specifications. 

In a separate submission to Docket 73-13, 
Wagner Electric requested clarification of the 
trailer test rig timing issue, which had been re- 
served in Notice 3 as a candidate for adoption 
at some later date. Midland-Ross also raised the 
issue with regard to a requested modification of 
Figure 1. The petitions pointed out tliat an 
NHTSA test showing a failure would be incon- 
clusive if it were compared to manufacturer 



testing conducted on a faster rig, and showing 
conformity. The remedy is to specify "legal 
baseline" actuation and release times, so the 
manufacturer will know the precise conditions 
under which his equipment must meet the re- 
quirements, and both government and industry 
testing can be conducted so as to produce conclu- 
sive results. The NHTSA therefore establishes 
the actuation and release values proposed in 
Notice 1 with minor modification. They will not 
become effective until September 1, 1975, to 
maintain the validity of testing already con- 
ducted. The values are set at two-significant- 
figure accuracy in agreement with Wagner that 
the values should match the actual trailer per- 
formance values. Because the actuation time is 
lowered to 0.06 seconds, the NHTSA may find it 
necessary to improve its test rig's speed by re- 
moving the tractor protection valve. Therefore, 
the valve has been made optional. The perform- 
ance of the test device had been modified from 
the original proposal so that initiating signal 
points are the same as for the actual performance 
tests, and so that initial release pressure agrees 
with the 95-psi requirement of the performance 
tests. 

Other issues raised by Wagner and Midland- 
Ross in petitions to Notice 3 will be answered in 
a later notice. 

March 1, l^'^h Proposals 

The NHTSA proposed modification of the 
standard's effective date, brake actuation times, 
and road and dynamometer tests as they apply 
to the service brake system and emergency stop- 
ping performance of all vehicles subject to the 
standard except trailers (39 F.R. 7966, March 1, 
1974). The proposals would have affected ve- 
hicle types separately to reflect the particular 
problems faced by fire fighting \ehicles. "special 
permit" vehicles, on/off-highway vehicles, and 
standard highway trucks and buses. Manufac- 
turer concern centered on the availability of 
components to meet the standard by September 1, 
1974, and tlie reliability of the antilock systems 
which will be utilized by most manufacturers to 
meet the requirements. Having carefully con- 
sidered the comments submitted in response to 
this proposal, the NHTSA hereby delays the 
standard's effective date for trucks and buses to 



PART 571; S 121— PRE 24 



Effective: September 1, 1974 
March 1, 1975 



March 1, 1975, and establishes interim require- 
ments for particular categories of vehicles essen- 
tially as they were proposed. 

The limited delay of effective date does not 
satisfy the requests of Ford and General Motors, 
who argued for a complete delay of the standard 
for one year, followed by limited implementation 
of the standard. Other comments, including 
those of Chrysler and Rockwell International, 
asked foi' significant delays of one year or more 
based primarily on component shortages which 
will be discussed separatelj' with regard to the 
specific problems of separate vehicle types. 

Ford argued that the stopping distance re- 
quirements mandated high-torque front brakes 
that could degrade suspension and steering char- 
acteristics of some vehicles to an unsafe level. 
Their submission to the docket and materials 
submitted in conjunction with a presentation to 
the NHTSA on March 28, 1974, included evi- 
dence of erratic handling and suspension distor- 
tion in high- and low-speed spike stops on the 
proving ground by short wlieelbase trucks. The 
American Trucking Association joined Ford in 
questioning vehicle handling under the stand- 
ard's requirements. 

Review of the Ford submission indicates that 
unmanageable suspension problems of this nature 
are generally encountered in short-wheelbase 
trucks with suspensions that have not been ade- 
quately modified for Standard 121 brakes. Other 
manufacturers have indicated in some cases that 
their solution to such severe instability has been 
a major redesign of the front axle and suspension 
system, or a decision to withdraw vehicles with 
especially short wheelbases from their product 
line. The NHTSA concludes that sufficient lead- 
time has been made available to all manufactur- 
ers to correct the steering and suspension prob- 
lems of reasonably-designed short-wheelbase 
vehicles, and that vehicles with wheelbases that 
are so short, and centers of gravity that are so 
high, that they cannot stop safely in the stop- 
ping distances specified should not be on the 
highway. 

Genera] Motors and other truck manufacturers 
argued for delay of the standard's effective date 
for one year to permit additional field testing of 
the reliability of current antilock devices. The 
likely effect of such a delay, however, would be 



further delay in the availability of production 
antilock components. One air brake equipment 
supplier believes "continued development will 
eventually improve their (antilock systems) over- 
all performance but most of these changes for 
refinement in electronics, improved pneumatic/ 
electronic response, durability, sensor standardi- 
zation and design standards require the normal 
evolution of field experience under real life con- 
ditions, using mass produced parts for a genuine 
field history." 

The reliability of antilock systems can pres- 
ently be judged on the basis of the performance 
of systems that are already in fleet test programs 
(and to a lesser extent by evaluation of antilock 
systems used for many years in passenger cars). 
One truck manufacturer has reported average 
miles between failures on fleet testing to be 
89,000 miles (176,000 miles in operations within 
the continental United States). A manufacturer 
of antilock equipment reported in February 1974 
that over 8,000 of its air brake skid control sys- 
tems are in field use, with excellent reliabilitj- 
experienced. Neither this manufacturer nor any 
other has reported any highway accident which 
was attributed to a malfunction of the antilock 
system. 

General Jlotors included in its list of antilock 
failures incorrect test procedures, missing fuses, 
and warning light malfunctions. "While these 
are not insignificant concerns, they are an indi- 
cation that unfamiliarity v.-ith the new system 
accounts for some of the malfunctions experi- 
enced in test programs. In addition, other mal- 
functions reported by General Motors are believed 
to be the result of systems being "added on" 
instead of being designed into the vehicles. 

General Motors and Ford reported accidents 
in their proving ground tests, which they believe 
illustrate what might happen if an antilock syF- 
tem malfunctions in service. The NHTSA has 
studied the accident information which was sub- 
mitted and has concluded that these accidents 
occurred as a result of rear wheel lockup during 
panic-type, full brake application and would also 
have occurred if the vehicles were not equipped 
with antilock systems. The NHTSA concludes 
that the reliability of antilock systems is such 
that their introduction will contribute to motor 
vehicle safety. 



PART 571; S 121— PRE 25 



Effective: September 1, 1974 
March 1, 1975 



Both the Ford and General Motors recom- 
mendations, as well as the other petitions which 
requested delays substantially greater than those 
proposed by the NHTSA, are excessively broad 
in that they would postpone all the safety bene- 
fits of the standard, because of specific problems 
in limited areas. The NHTSA proposal, by 
comparison, proposes only those modifications 
which are essential to implement the standard 
as rapidly and fully as possible. 

Because there was only a short interval be- 
tween the latest proposal and the effective date 
of the standard in which to implement any modi- 
fication of the standard, the proposal included a 
blanket 4-month delay of the standard's effective 
date for all affected vehicles. International 
Harvester, the largest manufacturer of air-braked 
vehicles that commented on the proposal, indi- 
cated agreement with the 4-month delay and 
stated their intention to build vehicles which 
comply with the standard after tJiat date. Gen- 
eral Motors noted the possibility that axles and 
the larger foundation brakes necessary to meet 
the standard would be available. The major 
supplier of axles to the truck and bus industry 
has estimated that, with no margin for error, 
some axles could be ready for January 1, 1975. 
The NHTSA has evaluated the current industrial 
shortage and leadtime problems precipitated by 
factors beyond manufacturer control and has 
concluded that a March 1, 1975, effective date as 
it applies to powered vehicles is necessary to 
allow the orderly implementation of Standard 
No. 121. The NHTSA cannot agree with Blue 
Bird Body Company that smaller manufacturers 
should automatically be granted a year to meet 
the standard following the availability of produc- 
tion components for Standard No. 121. 

The NHTSA has also determined that the pro- 
posed requirement that the test reservoir pressure 
reach 60 psi in 0.25 sec cannot be implemented 
prior to this effective date, and the proposal is 
therefore withdrawn. The modification of sys- 
tems to achieve this requirement could negate the 
compliance test data which has been accumulated 
by many manufacturers. 

Most comments which requested a longer delay 
of the effective date or more specific relief were 
addressed to the problems of specific vehicle 
types. There were no specific comments, how- 



ever, on the proposed 1-year delay in the ap- 
plicability of the standard to fire fighting 
vehicles. Accordingly, the standard is amended 
to apply to fire fighting vehicles only after 
September 1, 1975. 

The comments on "special permit" vehicles 
(defined in the proposal liaving a 108-inch over- 
all width or a 24,000-pound gross axle weight 
rating (GAWR), centered on the inadequacy of 
the definition when applied to "heavy hauler" 
trailers. Trailers are dealt with in a separate 
notice of proposed rulemaking published in to- 
day's Federal Register. The few comments ad- 
dressed to "special permit" trucks favored the 
September 1, 1976, effective date, but suggested 
more time might be necessary to acquire the 
necessary components because of their low prior- 
ity in suppliers' engineering programs. At this 
time the NHTSA amends the standard to grant 
these vehicles a September 1, 1976, effective date. 
Any supply problems beyond that will be consid- 
ered at a later time as they arise. 

On/ Off -Highway Vehicles: Comments on the 
proposal to substitute dynamometer requirements 
for stopping distance requirements until Septem- 
ber 1, 1975, for trucks that have a front steerable 
axle with a GAWR of 16,000 pounds or more, 
or a front steerable drive axle, fell into two 
groups. Comments either argued tliat the delay 
was insufficient, particularly with regard to front 
steerable drive axles, or they objected to par- 
ticular aspects of the relaxed interim require- 
ments. 

The NHTSA has decided to maintain the 
September 1, 1975, date for the full stopping 
distance requirements. An evaluation of all 
available information in this area indicate that 
air brake components will be available to meet 
the required level of performance for vehicles in 
this category. 

Manufacturers raised objections to the pro- 
posed interim requirements as they were ex- 
pressed in S5.3.1.2 and S5.7.2.3.1. Wagner 
Electric, General Motors, White, and Diamond 
Reo requested clarification that the S5.3.1.2 re- 
quirement would apply to "straight" trucks as 
well as towing vehicles. The language of S5.3.1.2 
makes clear that any trucks in the described 
category need not meet certain stopping distance 



PART 571 ; S 121— PRE 26 



Effective: September 1, 1974 
March 1, 1975 



requirements if their brakes conform to the 
formula in S5.4.1. 

Wagner, Mack, and Abex questioned the pro- 
posed requirement that the dynamometer vahies 
be applied to each axle system separately, instead 
of being summed for the entire vehicle braking 
system. The axle-by-axle dynamometer approach 
was specifically included in the proposal to ensure 
that brakes would be provided on the front axle 
and not to minimize braking on the rear axle. 
Therefore this section is modified to require a 
certain level of performance for the front axle 
and a sum total of performance overall. If a 
specific value were not required for the front 
axle, manufacturers would be tempted to make 
minor modifications of 2)resent front axle systems 
and thereby avoid the opportunity to gain ex- 
perience with the newer, stronger foundation 
brakes and axles. 

The language "the brakes on each wheel" in 
S5.3.1.2 confused Abex with regard to the dyna- 
mometer test requirements. To clarify the re- 
quirement while in no way changing it, the 
wording is amended to ''its brakes." 

In answer to AVagner's request for a definition 
of "axle system", the term is used in the same 
sense as it is used in the definition of GAWR 
found at 49 CFR § 571.3. "Axle system" is used 
instead of "axle" to avoid confusion in situations 
where a suspension system does not employ an 
axle. The term has not created difficulty in the 
GAWR definition. 

The S5.7.3.2.1 requirement for dynamometer 
testing in place of emergency stopping perform- 
ance testing parallels the S5.3.1.2 requirement. 
General Motors has pointed out, however, that 
dynamometer testing of spring brakes often 
found in emergency brake systems is imprac- 
ticable. Wagner also points out that the re- 
quirement can be viewed as redundant in view 
of S5.3.1.2. In view of these objections, the 
NHTSA concludes that retention of the emer- 
gency stopping requirement (except for the 
stopping distance) would be preferable to a 
dynamometer requirement. For tlie interim 
period, therefore, the vehicle will be required to 
come to a stop within the 12 foot lane using its 
emergency braking system. 



Highway Trucks and Buses: For powered ve- 
hicles that do not fall in the categories treated 
above, the proposal would have lengthened stop- 
ping distance requirements 5 percent to com- 
pensate for the variations expected in early 
production components that affect stopping per- 
formance. Most manufacturers argued that the 
5 percent longer distances would be required for 
the indefinite future, because production varia- 
tions would continue to affect performance sig- 
nificantly. The NHTSA established the stopping 
distances on the basis of the ability of available 
equipment, and expects that experience in the 
production of these components will lead to pre- 
dictable quality and the assurance that a vehicle 
will in fact perform as well as it is designed to. 

AVhite Motor Company suggested a clarifica- 
tion of S5.3.1.3 and S5.7.2.3.2 to make clear 
that the test procedures for the proposed Table 
V stops are identical to those in S5.3.1 for the 
Table III stops. The change has been made 
without in any way changing the requirements. 

Other Issues: Two proposals which affected 
most trucks and buses were the brake actuation 
time of 0.35 sec and the option of a manual pres- 
sure reduction valve to limit air pressure to the 
front axle. Nearly all manufacturers supported 
the 0.35-sec actuation time for trucks and buses 
and requested tliat it also be extended to trailers. 
The NHTSA amends the standard as proposed 
for truck and bus brake actuation. Trailer 
brake actuation requirements will not be changed, 
however, in light of the inuninence of the effec- 
tive date and the consequent need for stability in 
the standard. 

The manual pressure reduction vlve proposal 
was not supported as expected. Even Ford and 
General Motors, who questioned the safety of 
high-torque front brakes, did not agree that the 
valve would have a positive safety benefit. In 
view of the sharp disagreement in the comments 
over the usefulness of the valve in the hands of 
different drivers, the proposal is withdrawn. 

In the course of their comments on the pro- 
posal, several manufacturers and suppliers indi- 
cated uneasiness about the policy of the NHTSA 
with regard to isolated failures of components 
that have been certified as complying with Stand- 
ard No. 121. Some comments expressed a belief 



PART 571; S 121— PRE 27 



Effective: September ), 1974 
March 1, 1975 

that the NHTSA was adopting or announcing a 
new policy regarding compliance, with reference 
to a panel discussion at the February 25, 1974, 
meeting of the SAE in Detroit. The remarks 
in question, by an NHTSA Assistant Chief 
Counsel, were to the effect that the agency ex- 
pects that each manufacturer will design his ve- 
hicles and his test program so as to constitute 
due care that each of his vehicles complies with 
the standard. That is not a new policy, however, 
but merely a statement of the requirements of 
the National Traffic and Motor Vehicle Safety 
Act, which has been followed continuously by 
this agency. The NHTSA has avoided a rigid 
position that each failure necessarily constitutes 
a violation of the Act, just as it has the position 
that some percentage of failures is automatically 
"allowable." What constitutes due care in a 
particular case depends on all relevant facts, in- 
cluding such things as the time to elapse before 
a new effective date, the availability of test 
equipment, the limitations of current technology, 



and above all the diligence evidenced by the 
manufacturer. 

All interested persons should note that, al- 
though a proposal was necessary with regard to 
changes for trailer manufacture, the NHTSA 
does not intend to make any other amendments 
of Standard 121 before its effective dafe. 

In consideration of the foregoing. Standard 
No. 121 (49 CFE 571.121) is amended 

Effective Date: September 1, 1974, for trailers; 
March 1, 1975, for trucks and buses. 

(Sees. 103, 119, Pub. L. 89-563, 80 Stat. 718; 
15 U.S.C. 1392, 1407 ; delegation of authority at 
49 CFR 1.51.) 

Issued on May 14, 1974. 

James B. Gregory 
Administrator 

39 F.R. 17550 
May 17, 1974 



PART 571; S 121— PRE 28 



Effactiv*: January I, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 4) 



This notice amends Standard No. 121, Air 
brake systems, 49 CFR 571.121, to delay the 
effective date of the standard as it applies to air 
brake-equipped trailers until January 1, 1975. 

The January 1, 1975, effective date was pro- 
posed in a notice published May 17, 1974 (39 
F.R. 17563) which invited comments on the pro- 
posal until June 17, 1974. On the basis of urgent 
requests by manufacturers and the Truck Trailer 
Manufacturers Association, a new comment clos- 
ing date of June 4, 1974, was established for the 
effective date issue (39 F.R. 18664, May 29, 1974). 
The separate issue of a new "heavy hauler trailer" 
category is still subject to the June 17 date for 
comments, and further action will be decided on 
after that date. 

Only three commenters, out of the fifty who 
responded, opposed the 4-month postponement. 
These three were suppliers to the trailer indus- 
try who claimed that they were ready to provide 
the needed components by September 1, 1974, 



and stated that a delay in the effective day would 
entail additional costs to them. The NHTSA 
finds, however, that the September 1, 1974, date 
does not provide sufficient time for an orderly 
transition to production of the trailers with the 
new components, and that a delay until January 
1, 1975, is therefore in the interest of motor ve- 
hicle safety. 

In consideration of the foregoing, the effective 
date of Standard No. 121 (49 CFR 571.121) is 
changed from September 1, 1974, to January 1, 
1975, as it applies to trailers. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718, 
15 U.S.C. 1392, 1407; delegation of authority at 
49 CFR 1.51.) 

Issued on June 6, 1974. 

Robert L. Carter 
Acting Administrator 

39 F.R. 20380 
June 10, 1974 



PART 571; S 121— PRE 29-30 



I 



Effective: January 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 5) 



This notice amends Standard No. 121, Air 
brake systems, 49 CFR 571.121, to delay the ef- 
fective date for a category of specialized trailers 
whose configuration makes compliance with the 
standard particularly difficult until September 1, 
1976. A new definition is added to the standard 
to define the specialized "heavy hauler trailer" 
category. 

The definition and effective date were proposed 
in a notice published May 17, 1974 (39 F.R. 
17563). The proposed definition read: 

"Heavy hauler trailer" means a trailer with 

one or more of the following characteristics: 

(1) Its brake lines are designed to adapt 
to separation or extension of the vehicle 
frame; or 

(2) Its body consists of a platform whose 
primary cargo-carrying surface is not more 
than 40 inches above the ground in an un- 
loaded condition. 

None of the comments directly addressed to 
specialized trailers objected to the 1976 date. 

Wagner Electric suggested that the definition 
could be misconstrued to include trailers with 
bodies that consist of a cargo-carrying surface 
and sides and a header. It does appear that the 
definition can be more specifically stated, per- 
mitting only a header for safety purposes, and 
sides of a temporary nature. The definition has 
been modified accordingly. 

Some comments recommended broadening the 
reach of the definition to higher trailers. Nabors 
suggested a specific exemption for pole trailers. 
Kornylak requested exemption of its Stradolift 
vehicle, and Bankhead requested exemption of 
auto-hauling trailers. 

The suggestions to expand the definition to 
specific trailer types would broaden the exemp- 



tion beyond what is necessary to implement the 
standard. The definition presently reflects the 
necessary design characteristics of specialized 
trailers which, as a whole, require more develop- 
ment before they can comply with the standard. 
Hauling automobiles, for example, does not re- 
quire 15-inch wheels. A pole trailer which is 
not extendable does not require longer brake 
actuation and release times than the standard 
highway van. 

Other comments recommended raising the 40- 
inch bed limit to accommodate more vehicles. 
The NHTSA has concluded that trailers with 
beds higher than 40 inches (including trailers 
whose beds are below 40 inches over the wheels 
but higher than 40 inches over the fifth wheel) 
can accommodate the new larger brake packages 
available at this time. 

In consideration of the foregoing. Standard 
No. 121 (49 CFR §571.121) is amended by a 
modification of the paragraph on the applicabil- 
ity of the standard and by the addition of a new 
definition. . . . 

Effective date: January 1, 1975. It is found 
that this amendment causes no additional burden 
to manufacturers and, because the general effec- 
tive date of the standard for all trailers is 
January 1, 1975, this delay of effective date for 
certain trailers must be effective sooner than 180 
days of issuance and no later than January 1, 
1975. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407); delegation of authority 
at 49 CFR 1.51.) 

Issued on July 30, 1974. 

James B. Gregory 
Administrator 
39 F.R. 28161 
August 5, 1974 



PART 571; S 121— PRE 31-32 



Effective: March 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 6) 



This notice responds to six petitions for re- 
consideration of recent amendments to Standard 
No. 121, Air brake systems, 49 CFR 571.121, 
which established a March 1, 1975, effective date 
for trucks and buses, and optional interim re- 
quirements until September 1, 1975, for trucks 
with certain heavy or front steerable drive axles. 
In addition, this notice also responds to several 
questions on the burnish procedure recently 
raised by International Harvester. 

The NHTSA established the March 1, 1975, 
effective date for trucks and buses after compre- 
hensive consideration of numerous petitions from 
manufacturers and users of air brake-equipped 
vehicles (39 F.R. 17550, May 17, 1974). Manu- 
facturer concerns centered on the availability 
and reliability of components involved in the 
new brake systems, particularly antilock devices, 
and on leadtime necessary to modify vehicles to 
accept these components. 

Ford Motor Company is the only manufac- 
turer of air brake-equipped trucks which peti- 
tioned for reconsideration of the March 1, 1975, 
implementation date for the standard's basic 
provisions. After the time for petitions for re- 
consideration had closed, Chrysler Corporation 
reported on an accident which occurred during 
certification testing of a vehicle equipped with 
antilock devices, and urged the delay of Stand- 
ard No. 121 for an indefinite period. The Amer- 
ican Institute of Merchant Shipping also 
requested an indefinite delay in the standard's 
implementation. 

Ford petitioned for a further 6-month delay 
in the standard as it applies to truck-tractors, 
and a one and one-half year delay as the stand- 
ard applies to other trucks and buses. Ford 
asserts that the suspension and brake modifica- 



tions necessary to meet the dry-stopping distance 
requirements will compromise vehicle handling 
and stability, increase the danger of load shifts, 
and force the introduction of antilock devices 
before Ford considers them reliable. The re- 
quested extension would be used to evaluate the 
effect of the new componentry on overall safety. 

The issues in the Ford petition have been care- 
fully considered by the NHTSA in the process 
of rulemaking and, with the exception of load 
shifting, were addressed in the preamble to the 
amendments which established the March 1, 
1975, date. The NHTSA has reviewed each of 
Ford's concerns, and concludes that implementa- 
tion of the standard as scheduled for trucks and 
buses is reasonable, practicable, and meets the 
need for motor vehicle safety. 

With regard to the handling and stability 
problems experienced by some short-wheel-based 
vehicles in meeting the stopping distance re- 
quirements, the NHTSA maintains its determi- 
nation that adequate time has been made 
available to make the major redesign necessary 
in some vehicles, or to make the decision to dis- 
continue the production of models which are 
simply too short to meet the requirements despite 
design changes. International Harvester, in its 
comments on the rulemaking, indicated that it 
had been ready to meet the proposed January 1, 
1975, effective date and would actually suffer 
economic losses in waiting for the March 1, 1975, 
implementation. 

The availability and reliability of antilock 
systems which will be used by many manufac- 
turers in meeting the requirements was ques- 
tioned by Ford in its petition. In response to 
Ford's assertion that a manufacturer's report on 
field experience with 8,000 antilock units does 



PART 571; S 121— PRE 33 



Effective: March 1, 1975 



not appear in the record, a letter from Kelsey- 
Hayes (February 1, 1974) containing this infor- 
mation was placed in the NHTSA Docket 
Section before March 1, 1974. The NHTSA 
continues to monitor antilock production and 
testing and cannot agree that the evidence indi- 
cates antilocks will decrease the safety of the 
new trucks in highway operation. Since May, 
the NHTSA engineering staff has visited six of 
the seven major antilock manufacturers to dis- 
cuss antilock reliability and availability. At 
least half of these manufacturers pointed out 
that their plants were prepared for full produc- 
tion to meet the September 1, 1974, date, and 
that they had had to delay production schedules 
because of the six-month delay. Low volume 
production is presently available to vehicle 
manufacturers for their testing and evaluation. 

Concerning antilock reliability, a substantia! 
amount of proprietary information was reviewed 
as well as the publicly-known information that 
no highway accident has been attributed to the 
failure of antilock devices. Kelsey-Hayes 
pointed out that it is selling approximately 250 
axle units each month for retrofit. Following 
these visits, the NHTSA sent the seven major 
antilock manufacturers requests for reliability 
data under its investigatory authority, which 
will become part of the record although it may 
be of a proprietary nature which would justify 
not making it public. This data will show mil- 
lions of axle miles of antilock operation with a 
malfunction rate comparable to other equipment 
presently in highway service, and no highway 
accidents attributable to the device. 

Chrysler Corporation reported on a proving- 
ground accident on May 16, 1974, in which an 
antilock-equipped truck rolled over after its rear 
wheels locked and caused skidding during a stop 
from 60 mph. The manufacturer of the antilock 
system reported that the device functioned as it 
was designed to but in respon-se to a false signal. 
The important point, however, as noted in the 
May rulemaking, is that the accident occurred 
as a result of rear-wheel lockup during a panic- 
type, full brake application that would also have 
occurred if the vehicle had not been equipped 
with antilock. In other words, a panic stop 
always involves the risk of uncontrolled skid due 



to lockup, and the presence of the antilock only 
improves the chances of a safe stop in the vast 
majority of instances in which it functions 
properly. 

Ford requested an interpretation of S5.5.1 of 
the standard that would permit use of a pressure 
limiting valve to the front axle that operates 
when it senses electrical failure of the antilock 
system. The NHTSA has advised Ford (and 
Bendix Corporation) that S5.5.1 does not pro- 
hibit use of such a valve designed to operate in 
the event of electrical failure. 

Ford also raised the problem of load shift 
under heavy braking. The NHTSA has consid- 
ered the effects of the standard and notes that, 
under normal circumstances, stops will continue 
to be made at the same deceleration as in the 
past, consistent with driver comfort and load 
stability. Only in emergency situations will the 
full torque of the new brakes be utilized and in 
this event, the NHTSA concludes that the 
shorter stopping distances outweigh the possible 
safety problem of load shift. 

The Ford petition pointed out that any failure 
of component manufacturers to supply the new 
121 components would make compliance with 
the standard impossible. As of this date the 
NHTSA finds that supplier production is on 
schedule and will provide components on time. 
As recently as July 26, 1974, Rockwell Interna- 
tional assured the NHTSA that its production 
is on schedule. 

For these reasons the Ford petition and 
Chrysler request are denied. The NHTSA 
would like to establish the issuance of this notice 
as the final form of Standard No. 121 with re- 
gard to its effective date and the stopping dis- 
tance requirements, for i)urposes of review under 
§ 105(a)(1) of the National Traffic and Motor 
Vehicle Safety Act of 1966 (15 U.S.C. §1394). 
Thus, while several areas treated later in this 
notice will be subject to further reconsideration, 
the effective dates and stopping distance require- 
ments will be final as to any person who will be 
adversely affected by them. 

While International Harvester supported the 
March 1, 1975, date for standard highway trucks 
and buses (it would have preferred a January 1, 



PART 571; S 121— PRE 34 



EfFective: March 1, 1975 



1975, date), they did petition for reconsideration 
of the NHTSA decision to apply the full stop- 
ping distances to vehicles equipped with front 
steerable drive axles after September 1, 1975. 
White Motor Company and Diamond Reo 
Trucks, Inc., also petitioned for 1 year's delay in 
implementation of the full requirements for 
these axles. 

The majority of front stserable drive axles are 
found on vehicles which use the road regularly 
at highway speeds and which require the same 
stopping capability as lighter vehicles. In most 
cases, their non-planetary construction permits 
an uncomplicated adaptation to the standard's 
torque requirements. Furthermore, one vehicle 
manufacturer indicates that it has successfully 
redesigned steerable drive axles in the 18,000- 
to 23,000-pound GAWR range to meet Standard 
No. 121. White, International Harvester, and 
Diamond Reo state that the lighter axles in this 
category are unavailable, but not technically un- 
feasible. The unavailability stems from supplier 
decisions to concentrate on the more common 
non-driving axles found on standard highway 
vehicles in great numbers. An August 8, 1974, 
letter from Rockwell Standard to Docket 74—10 
supports the conclusion that the axles can be 
manufactured, but will not be available until 
September 1, 1976. Accordingly, the NHTSA 
has reconsidered the present effective date of 
September 1, 1975, for full requirements ap- 
plicable to front steerable drive axles and delays 
for one year the full requirements for those axle 
sizes which are not available until September 1, 
1976. 

Diamond Reo and White also requested recon- 
sideration of the implementation of full require- 
ments for vehicles equipped with a front steerable 
non-driving axle with a GAWR of 16,000 pounds 
or more, which are subject to interim dynamom- 
eter requirements from March 1, 1975, to Sep- 
tember 1, 1975. The manufacturers base their 
requests for a 1-year delay on difficulties in se- 
curing a proven brake assembly capable of han- 
dling the higher torque levels. B. F. Goodrich 
recently dropped development of its heavy air- 
over-hydraulic disc brake system, to which at 
least one truck manufacturer, White Trucks, was 
committed. "WTiite states that disc brakes are 



necessary for heavy front axles and has encoun- 
tered severe axle-to-axle imbalance problems in 
its attempts to use other disc brake assemblies 
at this date. A major axle supplier has notified 
the NHTSA that the axle itself can be ready by 
September 1975. 

The NHTSA has evaluated the foundation 
brake assemblies available to this vehicle group 
and concludes that a year's field testing and ex- 
perience is necessary and desirable to assure that 
the new components will perform as designed 
when placed in highway service. For this reason 
the full requirements of Standard No. 121 will 
become effective for vehicles with a front steer- 
able axle of 16,000 pounds GAWR or more on 
September 1, 1976. 

With regard to this vehicle grouji. Interna- 
tional Harvester claimed that the requirement 
that the brakes be "fully applied" was unfairly 
introduced into the interim requirements and 
interferes with braking action. Apparently full 
pressure applications may cause erratic behavior 
in some large vehicles with very light bodies, 
during dry stoj^s in the unloaded condition. 

Full application is required to ensure that ve- 
hicles provide the lateral tractive capability of 
an unlocked wheel during panic braking. This 
interim requirement was proposed in March 1974 
as relief from full requirements which have been 
in effect since February 1971. The NHTSA 
does not consider it unfair to propose and make 
final an optional stopping requirement which 
represents relief from more stringent require- 
ments. More important, the NHTSA considers 
it crucial to maintain complete directional sta- 
bility in a panic stop, loaded or unloaded, if the 
vehicle is unable to meet the stopping distance 
requirements in that condition. Accordingly, 
the International Harvester petition is denied. 

Diamond Reo also requested that the interim 
stopping distances for standard highway vehicles 
be adopted as the full requirements. Their ve- 
hicles meet the shorter distances but not by a 
sufficient margin to absolutely assure them that 
every one of their vehicles will pass. The fact 
that the vehicles are capable of stopping well 
within the shorter distances persuades the 
XHTSA that this safety level can and should 



PART 571; S 121— PRE 35 



Effeellve: March 1, 1975 



be maintained. Manufacturers are required by 
the Safety Act to "exercise due care" in certify- 
ing that vehicles comply with the applicable 
standards (15 U.S.C. § 1397(b) (2)). In view 
of the statutory language, Diamond Reo's re- 
quest for reconsideration is denied. 

In a related matter, the NHTSA has been 
asked by the Federal Register to redesignate the 
present Table V as Table Ila, which is accom- 
plished in this notice. 

Manufacturers raised several matters which 
were not addressed by Notice 2 and are not, 
therefore, properly raised as petitions for recon- 
sideration. The NHTSA finds it desirable, how- 
ever, to respond to them in this notice, in view 
of the standard's imminent effective date. 

Most important was a question by Interna- 
tional Harvester in a July 27, 1974, visit by 
NHTSA engineers to their plant. They indi- 
cated that some 121 vehicles may have difficulty 
in achieving the required burnish temperatures 
because of the use of the automatic pressure lim- 
iting valve that tailors the torque at the front 
axle. The burnish conditions of Standard No. 
121 essentially standardize the preparation of 
new truck, bus, and trailer brakes for testing 
under the standard. 

In the absence of a specification for these 
valves, it appears that manufacturers have in- 
stituted various practices to assure uniformly 
good burnishes. It is apparent that different 
vehicles respond to the burnish procedure with 
distinctive problems and require solutions tail- 
ored to their particular brake packages. 

From a regulatory standpoint, however, an 
optional procedure complicates enforcement of a 
standard, particularly where a manufacturer has 
tested one way and the NHTSA tests the other. 
Test results with the limiting valve, for example, 
may not be easily comparable with test results 
in which the valve was bypassed. Both the 
manufacturer and the NHTSA need a specifica- 
tion that permits flexibility in achieving a uni- 
form burnish in different vehicles, but does not 
permit two burnish options. 

To end this confusion, the NHTSA further 
specifies the burnish procedure to require that a 
limiting valve be in use except in the event the 
temperature of the hottest brake on a rear axle 



exceeds the temperature of the hottest brake on 
the front axle by 125° F. In this way the manu- 
facturer and the NHTSA will follow the same 
test procedure. It should be emphasized that 
this specification in no way invalidates the test- 
ing undertaken to date. Such data can be the 
basis of certification. 

In answer to another International Harvester 
question, brake adjustments can be made during 
the burnishing to control brake temperatures. 
It should be noted that NHTSA is considering 
a limit on adjustments to three, to be made only 
during the first 250 snubs. Finally, the NHTSA 
has indicated to Kelsey-Hayes that it would add 
"after-stop" to the burnish procedures to de- 
scribe the specified temperatures more precisely. 
The NHTSA intends to measure the tempera- 
tures within 30 seconds of brake release, but will 
not reject manufacturer readings taken at any 
time if they are reasonably related to the tem- 
peratures actually generated by the snubs. This 
latitude is necessary to avoid invalidation of 
manufacturer testing up to this time. 

International Harvester asked that the park- 
ing brake requirements of S5.6.2 be modified to 
require 20 percent grade holding ability "to the 
limit of traction". The NHTSA has determined 
that the present grade holding capability is de- 
sirable, and it has already provided an alterna- 
tive requirement in the standard that brakes with 
a specified static retardation force be provided 
on all axles. The NHTSA concludes that the 
option makes a reduction of the grade-holding 
requirements imnecessary. 

Diamond Reo requested that air reservoir 
volume on trucks and buses be reduced from 
present requirements. The NHTSA has already 
reduced the volume from 16 times the combined 
service brake chamber volumes to 12 times that 
volume, and concludes that a further reduction 
is not in the interests of motor vehicle safety. 
The Diamond Reo request concerning the anti- 
lock electrical circuit has already been answered 
by a letter denial of June 28, 1974. 

Wagner Electric requested a minor revision 
of Figure 1, Trailer Test Rig, which the NHTSA 
makes in the interests of consistency of terminol- 
ogy. The word "control" is substituted for 
"pedal". 



PART 571; S 121— PRE 36 



Effective: March 1, 1975 



Finally, the NHTSA has been receiving some 
indications that manufacturers may arbitrarily 
specify a higher GAWR than normal simply to 
avoid requirements of the standard. The 
NHTSA therefore takes this opportunity to ex- 
plain the manufacturer's responsibility to spec- 
ify the GAWR of axle systems on his products. 

The NHTSA defines gross axle weight rating 
as follows: 

"Gross axle weight rating" or "GAWR" 
means the value specified by the manufacturer 
as the load-carrying capacity of a single axle 
system, as measured at the tire-ground inter- 
faces. 

Because the GAWR is measured at the tire- 
ground interfaces, it means that the tires, wheels, 
brakes, and suspension components are included 
in the determination. It is obvious that the 
GAWR of the whole system cannot exceed the 
rating of any one component, such as tires. Both 
the NHTSA in its compliance tests and defects 
investigations, and the Bureau of Motor Carrier 
Safety on the road, will judge the vehicle on the 



basis of the values assigned. Therefore it is in 
the interest of the manufacturer to assign values 
which accurately reflect the load-bearing ability 
of the vehicle and its tires and suspension. 

In consideration of the foregoing, Standard 
No. 121 (49 CFR 571.121) is amended. . . . 

Effective date: March 1, 1975. Because the 
Standard's effective date for trucks and buses 
occurs sooner than 180 days and because these 
amendments create no additional burden, it is 
found for good cause shown that an earlier ef- 
fective date than 180 days from the date of 
publication is in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407); delegation of authority 
at 49 CFR 1.51.) 

Issued on November 6, 1974. 

James B. Gregory 
Administrator 

39 F.R. 39880 
November 12, 1974 



PART 571; S 121— PRE 37-38 



Effective: January 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 11) 



This notice amends Standard No. 121, Air 
brake systems, 49 CFR 571.212, to establish a new 
test category (and an effective date) for highly 
specialized tractor-trailer vehicle combinations, 
and to specify modified brake retardation force 
requirements for trailers until September 1, 1976. 

The National Highway Traffic Safety Admin- 
istration (NHTSA) proposed these actions, 
along with other actions that deal with special- 
ized trucks, in a notice published November 14, 
1974 (39 F.R. 40168). The NHTSA is acting as 
soon as possible on the retardation force and in- 
tegral tractor-trailer issues because they directly 
affect the manufacture of trailers, which will be 
subject to the standard's requirements on Jan- 
uary 1, 1975. The issue of exemption for over- 
size and specialized trucks (which have a March 
1, 1975, effective date) will be addressed in the 
near future by a separate notice. 

The NHTSA takes note of its recent proposal 
and request for comments on a postponement of 
this standard (39 F.R. 43639, December 17, 1974). 
The NHTSA is preceding with this rulemaking 
action independently of that proposal to maintain 
as much continuity as possible in the regulation 
as presently issued. 

The manufacturers and users of auto trans- 
porter combination vehicles and the Truck 
Trailer Manufacturers Association supported the 
proposal to exempt "integral tractor-trailers" 
from applicability of the standard until Septem- 
ber 1, 1976, because of their particular testing 
difficulties. It has been suggested that the term 
"integral tractor-trailer" should be replaced by 
a more descriptive designation of the combination 
vehicles in question. The NHTSA agrees and 
modifies the definition to refer to the transporta- 
tion of motor vehicles, and to change the defined 



term to "auto transporters." The comments re- 
quested deletion of a requirement in the defini- 
tion which limited these vehicles to those 
designed "by a single manufacturer, or person 
who alters a certified vehicle." The comments 
expressed concern that the phrase would eliminate 
the manufacture of tractor and trailer portions 
separately. Some manufacturers also believed 
that the reference to "certified vehicles" meant 
that any incomplete truck tractor equipped with 
121-type equipment would have to be certified 
upon completion by the manufacturer of auto 
transporters. 

The cited requirement does not exclude manu- 
facture by separate individuals of the two por- 
tions of the combination, although the preamble 
inadvertently referred to "trucks and trailers 
manufactured by a single manufacturer for use 
in combination." It is possible that one or more 
persons other than a vehicle manufacturer or 
alterer may be responsible for the integral de- 
sign. The NHTSA therefore deletes the phrase 
in question to permit continued flexibility in the 
design of these vehicles. 

The reference to alteration of a "certified ve- 
hicle" confused some businesses which modify 
stock truck-tractors for use in auto transporters. 
They believed that a completed vehcile that had 
been certified to meet Standard No. 121, or an 
incomplete vehicle with documents referring to 
Standard No. 121, could not qualify for an ex- 
emption as a portion of an auto transporter. In 
actuality, a complete and certified vehicle, or an 
incomplete vehicle, can be modified to become a 
portion of an auto transporter, which would 
thereby qualify for exemption whatever its pre- 
vious status. 



PART 571; S 121— PRE 39 



Effective: January 1, 1975 

Bankhead Transportation requested clarifica- 
tion with regard to manufacture of new auto 
transporter trailers to be fitted to existing truck 
tractors that are modified to accept the new 
trailer, These trailers constitute a portion of an 
auto transporter and as such are exempt until 
September 1, 1976. The NHTSA has modified 
the language of S5.3 in one respect from tliat 
proposed, to make clear that a transporter trailer 
manufactured without an equivalent transporter 
tractor would be tested separately under the re- 
quirements of S5.3.2 after September 1, 1976. 

The NHTSA also proposed that the retarda- 
tion force requirements of the standard, which 
apply to trailers (and, of an optional basis, to a 
small category of large trucks until September 1, 
1967), be somewhat reduced because of the degree 
of variability being experienced in brake lining 
performance. The NHTSA requested comments 
on lower values and on whether such new values 
should be permanent, or only temporary while 
further information is developed on variability. 

With the exception of General Motors Cor- 
poration and Automotive Research Associates, 
Incorporated (which suggested changes in dyna- 
mometer procedures instead of values), the com- 
mentors supported the reduction of retardation 
force values for trailers. General Motors argued 
that brake force reductions of the trailer should 
not be undertaken without similar reductions in 
stopping distance requirements for trucks, and is 
particular towing vehicles. 

The NHTSA, in an amendment published May 
17, 1974 (39 F.R. 17750), has already acknowl- 
edged the variability of production brake assem- 
blies on trucks and buses by establishing longer 
stopping distances for an interim period until 
September 1, 1975. The NHTSA recently denied 
a petition by Diamond Reo to make these longer 
distances the permanent values of the standard 
(39 F.R. 39880). A Paccar Corporation petition 
presently under consideration on the subject of 
stopping distances also raises the issue of relaxed 
stopping requirements. The NHTSA concludes 
that its decision on that petition will be respon- 
sive to the points raised by General Motors. 

Several comments on the proposed lower re- 
tardation forces included data that further sub- 
stantiate the determination that variability of 



brake linings is not sufficiently small to permit 
100 percent compliance of every brake assembly 
at the present values. Wagner Electric Corpora- 
tion, which originally petitioned for use of the 
values proposed by the NHTSA, has submitted 
new data which support a slightly lower minima 
force level to support the desired mean perform- 
ance of approximately 60 pounds. Data supplied 
by Raybestos Manhattan demonstrate a varia- 
bility to the 3-sigma limit of slightly more than 
20 percent calculated by the NHTSA on earlier 
testing. Molded Materials Company disagreed 
that compatibility of combination vehciles re- 
quired 60 percent mean retardation values, but 
supported the proposed lower minimum force 
levels as a means to achieve compatibility. Abex 
Corporation supported the lower values so that 
actual production experience could be accumulated 
as a basis for future changes. 

The NHTSA concludes on the basis or sub- 
mitted data that values slightly lower than those 
proposed will better accommodate the demon- 
strated variability of brake lining material. 
Therefore, values of 0.06, 0.13, 0.20, 0.27, 0.34, 
0.41, and 0.47 will replace the present values for 
trailers. 

Manufacturers and users of brake lining 
differed on whether the new values should per- 
manently replace the previous values. The 
NHTSA did not receive conclusive information 
indicating that the variability in performance 
will remain in production units. The NHTSA 
concludes, therefore, that interim values will 
permit the accumulation of significant field ex- 
perience on vehicle compatibility and lining 
variability, and that a judg:nent will be made on 
the basis of that data in the future. 

Only Kelsey-Hayes commented on the proposal 
to apply these new retardation force values to 
trucks with heavy (or driving) front axles dur- 
ing their interim requirements. As a manufac- 
turer of front axle brake assemblies for this 
vehicle category, Kelsey-Hayes pointed out that 
the revision was not supported for truck front 
axle brake assemblies and would require an un- 
justified retooling for a period of no more than 
18 months. The NHTSA agrees that the data 
underlying the proposal supports a modification 
for trailer brake assemblies only. Accordinglv 



I 



PART 571; S 121— PRE 40 



Effective: January 1, 1975 



the NHTSA does not reduce the optional interim 
retardation force requirements for trucks speci- 
fied in S5.1.3.2. 

In a separate matter, Rockwell International 
Corporation asked whether the discussion of 100 
percent compliance with Standard No. 121's re- 
tardation force requirements was a modification 
of earlier NHTSA discussion on the "due care" 
responsibility of each manufacturer to ensure 
that each of his products meets the requirements 
of the standard (39 F.R. 17750, May 17, 1974). 
The requirement to exercise "due care" that each 
vehicle comply with Standard No. 121 is a statu- 
tory requirement (15 U.S.C. 1397), and the 
above-cited discussion remains the NHTSA 
position. 



In consideration of the foregoing, Standard 
No. 121 (49 C.F.R. 571. 121) is amended. . . . 

Effective date: Januarj' 1, 1975. Because of 
the imminent eflFective date of the standard for 
trailers (January 1, 1975), the National High- 
way Traffic Safety Administration finds, for good 
cause shown, that an effective date sooner than 
30 days is in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 (15 
U.S.C. 1392, 1407) ; delegation of authority at 49 
C.F.R. 1.51) 

Issued on December 31, 1974. 

James B. Gregory 
Administrator 

40 F.R. 1246 
January 7, 1975 



PART 571; S 121— PRE 41-42 



Effective: September 1, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

(Docket No. 74-10; Notice 12) 
Air Brake Systems 



This notice amends Standard No. 121, Air 
brake systems, 49 C.F.R. 571.121, to delete as of 
September 1, 1976, the emergency brake option 
that for trucks and buses permits automatic ap- 
plication of the parking brakes in place of a 
modulated emergency' brake system. A notice 
of proposed rulemaking to be issued shortly pro- 
poses modification of the air brake system park- 
ing brake requirements and the trailer emergency 
braking requirements. 

Based on a December 1972 petition from the 
American Trucking Associations (ATA), the 
NHTSA proposed elimination of the automatic 
parking brake for use as an emergency braking 
capability (38 F.R. 14963, June 7, 1973). In 
response to comments on that proposal which 
stated that leadtime was insufficient to implement 
the proposal by September 1, 1974, the NHTSA 
indicated it would defer final action to a later 
date and issue any changes with an effective date 
beyond September 1, 1974 (39 F.R. 804, January 
3, 1974). The NHTSA again indicated in May 
1974 that "the majority of the changes proposed 
in response to the ATA petition continue to be 
viewed favorably." (39 F.R. 17550, May 17, 
1974). The NHTSA has now completed its con- 
sideration of the modulated braking provision 
and hereby amends the standard as proposed in 
June 1973, with an effective date of September 1, 
1976, to permit adequate time for engineering 
necessary changes. It appears, in fact, that the 
majority of new brake systems are designed to 
meet generally the modulated emergency brake 
requirements. 

The fundamental change is elimination of the 
option that permits automatic application of the 
parking brakes in place of a modulated emer- 
gency brake system. The NHTSA agrees with 



the ATA that a driver should not be forced to 
use two different methods of applying the emer- 
gency brakes, depending on what vehcile he is 
driving at the time. 

In the parikng brake system proposal to be 
published shortly, it is proposed that the parking 
brake provisions found as options in the present 
S5.7 be made mandatory in a revised S5.6 park- 
ing brake section. Thus the present S5.7 require- 
ment that a vehicle with a modulated brake 
capability also have a parking brake capable of 
manual application at any service reservoir pres- 
sure level would be found in the parking brake 
section. Also the requirement that the parking 
brake be capable of application in the event of a 
failure of specific components common to the 
service brake and emergency braking systems 
would be moved to the revised parking brake 
section. Finally the requirement that a parking 
brake be releasable only if it can be reapplied 
would be found in the new parking brake 
provisions. 

Several other requirements proposed in June 
1973 for the modulated emergency brake system 
are found in this amendment. The modulated 
emergency brake must be applied, released, and 
be capable of modulation, by means of the service 
brake control. The NHTSA has concluded that 
the driver is most likely to maintain the best con- 
trol of his vehicle when he can modulate any 
braking available to him througd a single control. 
The emergency system must be capable of two 
full applications and releases in the event the 
service brake system fails. This ensures that a 
disabled vehicle can be safely moved off the 
roadway. 

As proposed in June 1973 and made final in 
this notice, the emergency brake system of a 



PART 571 ; S 121— PRE 43 



EffecHve: September 1, 1976 



towing vehicle must operate in the event the 
trailer air control line or the trailer supply and 
control lines fail. These requirements ensure 
that a loaded combination vehicle can stop in 
specified distances with a failed control line, and 
that a loaded straight truck (capable of towing) 
or "bobtail" tractor-trailer is capable of stopping 
in the event a trailer breaks away. Additionally, 
the service brake control of a towing vehicle must 
be capable of modulating the brakes on a towed 
vehicle following a failure on the towing vehicle. 
Also, the emergency stopping distance require- 
ment presently in the standard becomes the only 
permissible test of a truck or bus emergency brak- 
ing system. 

A new test condition has been added to specify 
when to vent the control and supply lines to 
atmosphere for test purposes. 



As noted above, the majority of these changes 
appear to be incorporated in large measure in the 
design of the new brake systems. The NHTSA 
concludes that truck and bus manufacturers are 
capable of meeting these modulated brake re- 
quirements by September 1, 1976. 

In consideration of the foregoing, Standard 
No. 121 (49 C.F.R. 571.121) is amended 

Effective date: September 1, 1976. 

(Sec. 103, 119 Pub. L. 89-563, 80 Stat. 718 (15 
U.S.C. 1392, 1407), delegation of authority at 49 
C.F.R. 1.51 and 49 C.F.R. 501.8). 

Issued on January 10, 1975. 

James B. Gregory 
Administrator 

40 F.R. 2989 
January 17, 1975 



PART 571 ; S 121— PRE 44 



\ 



Effecllva: Morch 1, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 14) 



This notice amends Standard No. 121, Air 
brake systems, 49 C.F.R. 571.121, to exempt a 
small category of oversize and construction ve- 
hicles from the applicability of the standard. 
The exemption criteria were proposed in a Jan- 
uary 28, 1975, notice (40 F.R. 4153), which ex- 
panded the criteria for this specialized vehicle 
category in response to comments on an earlier 
exemption proposal (39 F.R. 40168, November 14, 
1974). 

In making the proposal, the NHTSA tenta- 
tively determined that the specialized configura- 
tion of this small category makes compliance 
with the standard so difficult and expensive that 
an exemption from the standard would be justi- 
fied. It was noted that the vehicle function in 
these cases generally results in restricted opera- 
tion on the highway (e.g., at low speed, in permit 
operation, or during daylight hours) and that as 
a result, vehicle exposure on the highway is 
limited. 

The NHTSA proposed a series of criteria in- 
tended to comprehensively identify vehicles with 
these characteristics. Permanent exemption would 
be granted to any vehicle that has (1) an overall 
vehicle width of 108 inches or more, (2) a speed 
attainable in two miles of not more than 33 mph, 
(3) a speed attainable in two miles of not more 
than 45 mph, all-wheel drive, and no cargo- or 
passenger-carrying capacity, (4) an axle that has 
a GAWR of 29,000 pounds or more, (5) two or 
more front steerable axles with a GAWR of 
16,000 pounds or more for each axle; or (6) a 
steerable drive axle driven through gear reduc- 
tion contained within the wheel. 

Three of the numbered criteria ((3), (5), and 
(6) ) were intended to describe the lighter and 
more maneuverable vehicles whose drive axle con- 



figuration or high center of gravity make con- 
formity with the standard expensive and difficult. 
An example of this vehicle type is the large, 
carrier-moimted mobile crane. Based on sub- 
mitted comments, it appears that these criteria 
should be combined as a single compound cri- 
terion in order to avoid inequities in the applica- 
bility of the standard. Specifically, either of the 
criteria numbered (5) or (6) could, of itself, 
permit heavy or cargo-carrying vehicles on the 
highway at unlimited speed without 121-type 
brakes while far smaller vehicles would be sub- 
ject to the regulation. To accomplish the re- 
arrangement, the exception criteria numbered 
(3), (5), and (6) are combined in a new category 
(d) to require for this exception that an expected 
vehicle have a speed attainable in two miles of 
not more than 45 mph, no cargo- or passenger- 
carrying capacity, and either ( 1 ) all-wheel drive, 
(2) a steerable drive axle driven through gear 
reduction contained within the wheel, or (3) two 
or more front steerable axles. 

It is recognized that total withdrawal of the 
16,000-pound tandem steerable axle exemption 
would make those vehicles with an unlimited 
highway speed unavailable until the axles are 
developed or the vehicle speed is reduced to 45 
mph. Therefore the NHTSA will make final its 
proposed 16,000-pound exemption, but only for 
the interim period until September 1, 1976. 

With regard to the 45-mph maximum speed 
criterion, FMC Corporation suggested that the 
speed be raised somewhat to ensure that vehicles 
excepted on this criterion can use the interstate 
highway system. The NHTSA does not agree 
that it should encourage use on the interstate 
system of large, high-center-of-gravity vehicles 
that are not subject to a minimum braking stand- 
ard. Accordingly, FMC's request is denied. 



PART 571; S 121— PRE 45 



Effective: March 1, 1975 



Little comment was received on the other cri- 
teria. Ford Motor Company suggested a 24,000- 
pound figure in place of the 29,000-pound pro- 
posal. For reasons cited in the January proposal 
in response to an identical request by Mack this 
request is denied. 

To the degree that this amendment does not 
grant the requests for exemption raised by 
Marmon Transmotive in its December 23, 1974, 
letter to the Administrator, that petition is 
denied. 

In consideration of the foregoing, Standard 
No. 121 (49 C.F.R. 571.121) is amended. . . . 

Effective date: March 1, 1975. Because these 
amendments relieve a restriction and because of 



the imminence of the standard's effective date, it 
is found for good cause shown that an effective 
date sooner than 30 days from the date of their 
publication in the Federal Register is in the 
public interest. 

(Sec, 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 C.F.R. 1.51.) 

Issued on February 28, 1975. 

James B. Gregory 
Administrator 

40 F.R. 8953 
March 4, 1975 



PART 571; S 121— PRE 46 



EfFeclive: March 21, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 15) 



This notice amends Standard No. 121, Air 
brake systems, 49 C.F.R. •§ 571.121, in response to 
petitions for reconsideration of requirements 
established for trucks and buses, by revision of 
the retardation force requirements applicable to 
on/ofF highway vehicles until September 1, 1975, 
or September 1, 1976. 

The National Highway Traffic Safety Admin- 
istration (NHTSA) established the final form 
of Standard No. 121 for purposes of judicial re- 
view in November 1974 (39 F.R. 39880, Novem- 
ber 21, 1974) (Notice 6). Notice 6 established 
interim stopping distance requirements for stand- 
ard highway vehicles, and retardation force re- 
quirements for some on/ofT highway vehicles. 
Petitions for reconsideration of the decision were 
received from White Motor Corporation, Mack 
Trucks, International Harvester, PACCAR Cor- 
poration, Diamond Reo, and Breeze Corporations. 
General Motors effectively requested reconsidera- 
tion in its response to a separate November 
notice (39 F.R. 40168, November 14, 1974) (No- 
tice 7) by supporting reduced trailer require- 
ments only with corresponding reduction of truck 
stopping distance requirements. 

General Motors, in its response to Notice 7, 
indicated that similar 121 vehicles can register 
as much as a 20-percent difference in stopping 
distances as a result of uncontrolled variability 
in brake component performance. International 
Harvester, which until recently had supported 
5-percent longer stopping distances on an interim 
basis, now points to certain variables, including 
brake linings, in requesting longer distances on 
a permanent basis. Diamond Reo reported the 
same experience in its comments to Notice 2 of 
Docket No. 74-10. PACCAR requested that S5.3 
(stopping distance) be "temporarily repealed" 



and that longer stoping distances be considered 
for the future. The NHTSA concludes that 
PACCAR's request is essentially a petition for 
rulemaking to increase the stopping distances on 
a permanent basis. 

These positions raise issues which can arise 
whenever a standard is first implemented: (1) 
that production \ariables are so great that in- 
ordinate compilance margins are required and 
(2) that the brake packages necessarj' to achieve 
these compliance margins are so aggressive that 
the handling qualities and durability of affected 
vehicles are significantly degraded. The NHTSA 
is, of course, interested in receiving on a con- 
tinuing basis any new technical information (par- 
ticularly test data on production vehicles) that 
bears on these important safety issues. Based on 
the information submitted to date, however, 
NHTSA is not prepared to grant the outstanding 
petitions at this time. 

PACCAR also requested that the stopping 
distance requirements be delayed until the per- 
formance of antilock systems and certain test 
procedures, conditions, and the control trailer 
test device are specified in areas considered de- 
ficient by PACCAR. While these issues might 
appropriately be considered for future rulemak- 
ing, the NHTSA does not agree that change of 
these important elements of the standard should 
delay orderly implementation of the standard. 
Accordingly, the PACCAR request in these areas 
is denied. 

The second area of the standa rd in which man- 
ufacturers seek reconsideration is limited relaxa- 
tion of requirements for vehicles with front 
steerable drive axles (S5.3.1.2). Based on un- 
availability of this axle design, vehicles manu- 
factured before September 1, 1975, with a front 



PART 571 ; S 121— PRE 47 



EfFecHve: March 21, 1975 



steerable drive axle of any size may meet retarda- 
tion force requirements in place of stopping dis- 
tance requirements. Because of unavailability of 
the lighter front driving axles for a greater 
period, vehicles manufactured before September 
1, 1976, with a front steerable drive axle with a 
gross axle weight rating (GAWR) of less than 
18,000 pounds may meet retardation force re- 
quirements in place of stopping distance require- 
ments. 

Diamond Reo, International Harvester, and 
Mack Trucks, Inc., now request that the heavier 
axles also be permitted relaxed requirements un- 
til September 1, 1976. "White Motor Company 
in its response to Notice 10 of Docket No. 74-10 
requested the relaxed requirements imtil Septem- 
ber 1, 1977. The NHTSA indicated in Notice 6 
that this axle type is available and has been 
offered by Oshkosh Truck Company to the other 
manufacturers of this vehicle class. While Dia- 
mond Reo does not indicate it considered the 
Oshkosh axle, the other manufacturers indicate 
that redesign of their limited vehicle output in 
this area to accept the Oshkosh axle would be 
unjustified because of cost. Oshkosh, on the 
other hand, has offered to provide, at cost, tech- 
nical assistance in the installation of Oshkosh 
axles to non-Oshkosh pilot test vehicles, and 
consultation and review of test data obtained 
from truck-manufacturer-conducted tests. 

The NHTSA concludes, based on all informa- 
tion available, that the axle is available at this 
time and that sufficient leadtime has been made 
available for the location and testing of an axle 
of this type. The manufacturers who request 
further delay do not claim that the installation 
is technologically unfeasible or otherwise imprac- 
ticable. Although they cite adverse economic con- 
sequence for the limited numbers of vehicles they 
produce in this category, this argument does not 
consider the major economic consequences for the 
Oshkosh Company, who state that 72 percent of 
their vehicle production would be adversely af- 
fected by any further delay. The petitions of 
White, International Harvester, Diamond Reo, 
and Mack are accordingly denied. 

Due to unavailability until September 1, 1976, 
front steerable non-driving axles with a GAWR 
in excess of 16,000 pounds are permitted the same 



relaxed requirements as the driving axles just 
discussed. White Motor Corporation, in its com- 
ments to Notice 10 of Docket No. 74-10, requested 
the relaxed requirements be extended to Septem- 
ber 1, 1977, because of the long leadtime asso- 
ciated with manufacture of these vehicles. The 
NHTSA will monitor the availability of these 
axles to ensure their readiness for September 1, 
1976, and will consider a later effective date for 
them if they are not available as presently sched- 
uled. At this time, however, it appears that the 
axles will be ready sufficiently in advance of Sep- 
tember 1, 1976, to permit satisfaction of the full 
requirements on that date. Accordingly White's 
petition is denied. 

As earlier noted, both the vehicles equipped 
with certain driving or non-driivng front steer- 
able axles are permitted to meet retardation force 
requirements in place of distance requirements 
for an interim period. A reduction of these re- 
tardation force requirements was the subject of a 
proposal in Notice 7, which was acted on for 
trailers in Notice 11 (40 F.R. 1246, January 7, 
1975). It was concluded that no argument had 
been made for a temporary reduction of retarda- 
tion forces on the front axle of heavy trucks, 
most of which are integral trucks which ex- 
perience high levels of dynamic load shift during 
braking. Comments by PACCAR to Notice 6, 
however, emphasized that retardation force re- 
quirements at the rear axle could be reduced be- 
cause the load shift off the rear axle effectively 
results in over-torque of that axle. 

The NHTSA's intent in substituting retarda- 
tion force requirements for stopping distance is 
to ensure the best braking that is presently avail- 
able, and it appears that rear brake retardation 
requirements may, in some cases, inhibit the tai- 
loring of brake systems on different vehciles to 
achieve this goal. The most satisfactory means 
to reduce rear axle requirements while maintain- 
ing front axle requirements is to eliminate re- 
quirements for the vehicle as a whole, to permit 
the manufacturer latitude in selecting retardation 
force requireemnts at the rear axle. The present 
requirements for front axle retardation forces 
remain in the standard, and by this notice, the 
NHTSA deletes the requirement for retardation 
force values for the vehicle as a whole. 



PART 571 ; S 121— PRE 48 



EfFecllve: March 21, 1975 



PACCAR requested complete withdrawal of 
the retardation force requirements, as well as the 
brake power and fade requirements as they affect 
all trucks. The NHTSA, of course, considers 
these characteristics of a brake system funda- 
mental, and does not agree that the requirements 
are impracticable or should be withdrawn. 
PACCAR's request is therefore denied. 

With regard to the vehicles that may meet re- 
tardation force requirements in place of stopping 
distances. International Harvester requested con- 
firmation that S6.3.1.2 is an option that the man- 
ufacturer may choose to ignore in the loaded or 
unloaded condition if the vehcile in question meets 
the stopping distance requirements in that condi- 
tion. This agency stated in the preamble to 
Notice 6 that "the NHTSA considers it crucial 
panic stop, loaded or unloaded, if the vehicle is 
to maintain complete directional stability in a 
unable to meet the stopping distance require- 
ments in that condition." International Har- 
vester's understanding of this language is correct. 

PACCAR requested deletion of brake actua- 
tion requirements as redimdant in view of stop- 
ping distance requirements. The NHTSA has 
considered elimination of the requirements pre- 
viously, and concluded at that time that the re- 
quirement should be maintained (37 F.R. 3905, 
February 24, 1972). At this time the actuation 
requirements ensure fast braking on the vehicles 
under S5.3.1.2 which need not meet stopping dis- 
tance requirements. The NHTSA will consider 
this PACCAR request for future rulemaking but 
does not act on the petition for amendment at 
this time. 



Finally, PACCAR requested specification of 
antilock performance characteristics. The stand- 
ard does not require antilock systems, and the 
NHTSA has concluded that specification for man- 
ufacturers who utilize these devices would be 
design restrictive, without a corresponding safety 
benefit. No manufacturer other than PACCAR 
indicates that a safety need exists to specify the 
cycling of antilocks, and the NHTSA is unable 
to determine from the PACCAR petition what 
evidence exists that antilock specification would 
improve vehicle handling. PACCAR's petition 
is accordingly denied. 

In areas unrelated to the petitions for recon- 
sideration, the NHTSA corrects an error in 
S6.1.8.1 and adds a clarifying word to S5.7.1.2, 
without in any way changing the requirements 
of those paragraphs. 

In consideration of the foregoing. Standard 
No. 121 (49 C.F.R. § 571.121) is amended. . . . 

Effective date: March 21, 1975. Because of 
Standard No. 121's March 1, 1975, effective date 
and because this order relieves a restriction, it is 
found for good cause shown that an effective date 
sooner than 30 days from the date of publication 
of that order is in the public interest. 

(Sec. 103, 119, 89-563, 80 Stat. 718 (15 U.S.C. 
1392, 1407) ; delegation of authority at 49 C.F.R. 
1.51). 

Issued on March 14, 1975. 

James B. Gregory 
Administrator 

40 F.R. 12797 
March 21, 1975 



PART 571; S 121— PRE 49-50 



Effective: June 16, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 74-10; Notice 16) 



This notice responds to three petitions for re- 
consideration of the National Highway Traffic 
Safety Administration's December 31, 1974, deci- 
sion to implement Standard No. 121, Air brake 
systems, as scheduled on January 1, 1975, for 
trailers and on March 1, 1975, for trucks and 
buses. The petition of American Fire Apparatus 
Company for reconsideration of the September 1, 
1975, effective date for fire fighting apparatus is 
granted for a period of six months. The petitions 
of the Milk Industry Foundation and of Repre- 
sentative James H. Quillen for delay of the stand- 
ard as a whole are denied. The petition of White 
Motor Corporation has already been responded 
to by Notice 15 of Docket No. 74-10 (40 F.R. 
12797, March 21, 1975). 

The Milk Industry Foundation (the Founda- 
tion) requested delay of the standard as it applies 
to trucks and buses until March 1, 1976, to permit 
further testing of the new braking systems (and 
redesign as necessary) and to conduct an analysis 
of the economic impact of the standard. The 
Foundation believes that insufficient time has been 
allowed for vehicle testing. 

The NHTSA has evaluated the readiness of 
manufacturers to meet the standard throughout 
the four years since issuance. The original Jan- 
uary 1, 1973, effective date was delayed until 
September 1, 1974. In early 1974, the vehicle and 
component test programs involved in implemen- 
tation were again evaluated, and the NHTSA pro- 
posed delay of the effective date to January 1, 1975 
(39 F.R. 7966, March 1, 1974) (.39 F.R. 17563, 
May 17, 1974). Based on submitted comments, 
it was determined that a March 1, 1975, effective 
date for trucks and buses, and a January 1, 1975, 
date for trailers would permit adequate time to 
complete preparations for the standard's imple- 



mentation (39 F.R. 17750, May 17, 1974) (39 F.R. 
20380, June 10, 1974). These delays were under- 
taken although one manufacturer expressed 
readiness to meet the September 1974 date, and 
International Harvester, the largest manufacturer 
of air-braked vehicles, expressed readiness to 
meet the January 1, 1975, effective date. This 
decision was reevaluated in November 1974 and 
found to remain valid, although a few larger 
vehicle types were permitted a later date (39 F.R. 
39880, November 12, 1974). 

The Foundation also requested that the stand- 
ard be delayed until its economic impact is eval- 
uated. The NHTSA conducted an evaluation of 
economic impact shortly before implementation 
of the standard (39 F.R. 43639, December 17, 
1974) and, based on several hundred comments, 
concluded tliat the standard should be imple- 
mented (40 F.R. 1248, January 7, 1975). The 
NHTSA disagrees with tlie Foundation that the 
evaluation should ha\e been conducted in accord- 
ance with Executive Order 11821 (on inflation 
impact studies) when the final criteria and pro- 
cedures for implementation of the Order were 
not yet established. The NHTSA has committed 
itself to continue monitoring the effectiveness of 
its standard in accordance with its statutory 
mandate, with a view to identifying any modifica- 
tions that would lower costs while achieving com- 
parable levels of safety. 

As indicated by the submissions of the Milk 
Industry Foundation, there has evidently been 
much confusion among user groups such as the 
dairy industry over the effect of the braking 
standards on their operations. In order to meet 
tlie requirements that a vehicle stop in a specified 
distance when tested by the government, chassis 
manufacturers have in some cases specified center 



PART 571; S 121— PRE 51 



Efhctive: June 16, 1975 



of gravity heights for conformity purposes that 
are lower than the loaded center of gravity of 
trucks that these operators are accustomed to 
using. The body builders who complete and 
certify the trucks have passed these center of 
gravity specifications on to the user groups. This 
has given rise to fears on the part of the dairy 
industry and others that they must reduce the 
loads carried on their trucks. 

Actually, this is neither the legal effect nor 
the intended policy effect of the standard. The 
standard does not regulate the manner in which 
trucks are loaded or used on the road, and users 
are free to use their own judgment in loading 
their trucks, as they have been in the past. The 
standard is designed so that a properly-designed 
vehicle which satisfies its performance require- 
ments under the conditions stipulated for com- 
pliance testing will perform safely under all 
reasonable conditions or real world use. Trucks 
equipped with the stronger and better-modulated 
brakes required by the standard, when loaded 
similarly to those in the past, should in fact be 
much safer both for their occupants and for the 
rest of the driving public than comparable ve- 
hicles were before. If the NHTSA should dis- 
cover vehicles being produced that do not perform 
safely when loaded in a normal manner and can 
establish that this condition is attributable to 
deficiencies in vehicle manufacture or design, it 
can proceed against their manufacturers under 
its safety-related defect jurisdiction. 

Representative Quillen requested consideration 
of a significant postponement of the standard, 
believing that a delay would increase truck sales. 
An examination of the truck market indicates that 
several months' inventory of trucks manufactured 
without the new systems remained unsold on 
March 1, 1975, suggesting that the economic down- 
turn, rather than the new systems, accounts for 
many lost sales. The American Trucking Asso- 
ciations statistics on general freight tonnage in- 
dicate a steady decline in highway tonnage from 
the high figure reached in November 1973. It 
does appear that some of the slowdown is at- 



tributable to "pre-buying"' of trucks to avoid 
Standard No. 121, but this effect would occur 
wliatever the date of implementation. Accord- 
ingly the petitions of the Milk Industry Founda- 
tion and Representative Quillen are denied. 

American Fire Apparatus Company has re- 
quested that the NHTSA reconsider its decision 
to implement the standard as scheduled, so far as 
it applies to fire fighting vehicles. NHTSA policy 
has been to grant fire fighting vehicles a mini- 
mum of two years from the issuance of any 
standard to achieve compliance because of the 
unique leadtime i^roblems associated with the 
industry. (49 CFR §571.8). On this basis, the 
NHTSA granted a delay of the effective date 
from September 1, 1974, to September 1, 1975, 
for these vehicles at the request of American Fire 
Apparatus (39 F.R. 17750, May 17, 1974). At 
tlie same time the general implementation date 
was extended six months. The NHTSA agrees 
that fire fighting apparatus is entitled to a full 
year's delay because of its long leadtime problems. 

By this notice, the NHTSA denies all out- 
standing petitions for reconsideration of Stand- 
ard No. 121's effective dates, with the exception 
of the date for fire fighting vehicles. 

In consideration of the foregoing, Standard No. 
121 (49 CFR §571.121) is amended. . . . 

Effective date : June 16, 1975. Because the pre- 
viously established effective date for fire fighting 
apparatus was less than 180 days after the date 
of publication of this amendment in the Federal 
Register, it is found for good cause shown that 
an effective date less than 180 days from the date 
of publication is in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 (15 
U.S.C. 1392, 1407) ; delegation of authority at 49 
CFR 1.51). 

Issued on May 12, 1975. 

James B. Gregory 
Administrator 

40 F.R. 21031 
May 15, 1975 



PART 571; S 121— PRE 52 



Effective: September 1, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 



Air Brake Systems 
(Docket No. 74-10; Notice 17) 



This notice responds to six petitions for recon- 
sideration of a recent amendment of Standard 
No. 121, Air Brake Systems, 49 CFR 571.121. 
That amendment deleted as of September 1, 
1976, the emergency brake option that permits 
automatic application of parking brakes in place 
of a modulated emergency brake system on trucks 
and buses (40 FR 2989, January 17, 1975). In 
addition, that notice standardized the operation 
of the emergency brake control, specified a mini- 
mum number of emergency brake applications 
and releases, and provided for the integrity of 
the towing vehicle braking system in the event 
of failure of the air lines to the towed vehicle. 
On the basis of information and arguments pre- 
sented by several petitioners, the National High- 
way Traffic Safety Administration (XHTSA) 
hereby withdraws the amendment that specified 
a minimum number of emergency brake applica- 
tions and releases. 

None of the petitions for reconsideration ob- 
jected to the NHTSA's deletion of automatic 
parking brake application as a means of provid- 
ing emergency braking capability. There were 
no objections to the specification that the emer- 
gency brake system control be the same control 
as that for the service brake system. These pro- 
visions remain unchanged, and will become effec- 
tive September 1, 1976. 

The standard tests the emergency braking 
capability of a vehicle by introducing a ''single 
failure in the service brake system." Bendix 
Corporation requested that this requirement be 
replaced by a requirement for emergency brak- 
ing capability "with either circuit's reservoir at 
zero psi." Presumably Bendix is suggesting that 
the "split system" design found on today's air- 
braked trucks be tested by draining either side 



of the system. Standard No. 121 does not specify 
a particular type of emergency brake system and 
cannot therefore specify failing any particular 
component. The NHTSA believes a vehicle 
should be capable of making stable in-line stops 
within the specified distance with a failure in any 
hose or reservoir in the service brake system. 
For instance, a failure in the air hose to the right 
front wheel should not make it impossible for 
a driver to keep the vehicle within a 12 foot wide 
lane. The agency does intend to clarify the 
status of various air lines in powered vehicles, 
particularly towing vehicles, to answer questions 
raised by International Harvester and the State 
of California concerning service brake system 
failure. These clarifications will appear in an 
upcoming notice on parking brake systems. 

International Harvester, Ford, Midland-Ross, 
and Bendix objected to the requirement of So.7.3 
that requires the emergency brake system to be 
capable of not less than two applications and 
releases, as determined by brake chamber air 
pressure of 60 psi or more during the pressure 
phase of operation, and brake chamber air pres- 
sure of not more than 1 psi during the pressure 
release phase of operations. The manufacturers 
(and the American Trucking Associations) were 
concerned that the specification of 1- to 60-psi 
values was design-restrictive and would force 
substantial redesign of vehicles before the exist- 
ing new designs can be thoroughly tested. Some 
of the petitions questioned whether the test would 
be conducted statically or dynamically. 

The NHTSA is concerned that manufacturers 
not be upduly burdened with modifications to' 
their systems during the initial introduction pe- 
riod of the standard. The agency has regularly 
indicated in its correspondence that it is monitor- 



PART 571; S 121— PRE 53 



Effective: September 1, 1976 



ing implementation of the standard to minimize 
disruption and costs wliile maintaining the stand- 
ard's safety benefits. The maximum and mini- 
mum pressure values in question were specified 
simply as objective testing criteria and are not 
intended as design restrictions that fulfill a safety 
function. 

In view of the redesign problems noted and 
their accompanying disruption, the NHTSA 
withdraws the application-and-release specifica- 
tion and will not reestablish it without further 
notice and opportunity to comment. (In answer 
to Bendix's question, it is noted that the 60 psi 
value in the pressure release phase was not in- 
tended to replace the "zero-torque" criterion for 
release of spring brakes.) 

Midland-Ross, International Harvester, and 
Ford expressed several objections to the three 
requirements of S5.7.4 and the related test con- 
ditions of S6.1.14. The requirements are intended 
to assure that a combination vehicle remains 
capable of emergency braking performance in the 
event of hose failure between the towed and tow- 
ing vehicles, including failure of both hoses due 
to trailer breakaway. 

Comments incorrectly assumed that the re- 
quirements specify modulation of the trailer 
braking system in the event of hose failure under 
S5.7.4(b) and (c). In fact, section 85.7.4 does 
not require trailer braking requirements, but only 
specifies that a towing vehicle meet the enu- 
merated requirements under certain conditions. 

To eliminate confusion about the role of 
trailers in these tests, sections S5.7.4(a) and (b) 
are hereby revised to make it clearer that the 
vented line(s) to the trailer are only test con- 
ditions under which the towing vehicle must 
demonstrate emergency braking stopping distance 
capability. To eliminate a sepai'ate source of 
confusion in section S5.7.4(a), which is intended 
to simulate trailer breakaway, the section is also 
revised to eliminate an incorrect requirement for 
testing with a failed control line and an intact 
trailer supply line. 

Midland-Ross and International Harvester ob- 
jected to the test conditions of S6.1.14, which 
underlie S5.7.4(a) and (b). The S6.1.1.4 proce- 
dure is intended to simulate a trailer breakaway 
or, in the alternative, a failed control line on a 



loaded combination vehicle. International Har- 
vester expressed the belief that five new tests 
were thereby added to the standard. It is now 
made clear that only one additional test of a 
single-unit vehicle capable of towing is required, 
and two additional tests of a truck tractor are 
required. These tests are conducted in the test 
sequence at steps 4(e) (loaded) and 6(e) (un- 
loaded). 

International Harvester questioned as un- 
realistic the criterion in S6.1.14 that specifies a 
1-minute delay in braking following rupture of 
a brake line. The NHTSA recognizes that the 
towing vehicle protection system is expected to 
act in much less than 1-minute to protect the 
air pressure in the towing vehicle from the effects 
of a loss of air pressure in the towed vehicle. 
The 1-minute interval is intended only to permit 
adverse "testing-to-failure" of an inadequately 
designed system. As a practical matter, the 
NHTSA will test when air pressure is lowest 
during the 1-minute period. 

Midland-Ross implied in its comments on 
S6.1.14 that the S5.7.4(a) test would be con- 
ducted with a trailer attached whose emergency 
brake system is activated during testing. As 
noted earlier, S5.7.4 applies only to a towing 
vehicle and only its brakes are tested. In 
S5.7.4(a), no trailer is attached to the towing 
vehicle (simulating a breakaway). In S5.7.4(b), 
a trailer is attached (simulating a failure), but 
only tractor brake activation is permissible. 

Midland-Ross expressed the belief that S5.7.4 
(c) I'equires modulation of the trailer brakes 
in the event of a failed air control or supply 
line. In fact, the section only requires that a 
towing veliicle be capable of modulating the air 
in the supply or control line following a single 
failure in the service brake system on the tow- 
ing vehicle, but does not require modulation of 
the towed vehicle emergency brake system under 
any circumstances (including control line fail- 
ure). The requirement ensures that a single 
failure in the truck itself will not prevent modu- 
lation of an unimpaired system from the towing 
vehicle protection system rearwards. A clarifica- 
tion has been added to limit the single failure 
to the service brake system of the towing vehicle, 
not including either of the air lines to the towed 
vehicle. 



PART 571; S 121— PRE 54 



Because several modifications are being made 
to the requirements of S5.7 as previously pub- 
lished, the NHTSA is republishing the entire 
provisions of S5.7 as they will become effective 
September 1, 1976, although paragraphs S5.7, 
S5.7.1, S5.7.2, and S6.1.14 remain unchanged. 

In consideration of the foregoing, S5.7 of 
Standard No. 121 (49 CFK § 571.121) is amended, 
effective September 1, 1976. . . . 

Effective date : September 1, 1976. 



(Sec. 103, 119, Pub 
(15 U.S.C. 1392, 1407) ; 
at CFR 1.51.) 

Issued on July 23, 1975 



Effective: September 1, 1976 

L. 89-563, 80 Stat. 718 
delegation of authority 



James B. Gregory 
Administrator 

40 F.R. 31771 
July 29, 1975 



PART 571; S 121— PRE 55-56 



EfFeclive: August 27, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 2) 



This notice amends Standard No. 121, Air 
Brake Systems, 49 CFR 571.121, to establish new 
service brake system stopping distances until 
January 1, 1978, and increase brake actuation 
and release times on trucks, buses, and trailers. 
This notice also excludes from the standard 
trailers with an imloaded vehicle weight that is 
not less than 95 percent of the gross vehicle 
weight rating (GVWR), and any other vehicle 
with an unloaded vehicle weight that is not less 
than 95 percent of the GVWR and which has a 
maximum speed of 45 mph. 

The NHTSA proposed reduction of Standard 
No. 121's stopping distance requirements (40 FR 
24915, June 11, 1975), because data submitted 
by manufacturers of air-braked vehicles and air 
brake components indicated that variability of 
performance of certain braking and related com- 
ponents could in some vehicles necessitate more 
aggressive brake packages than are desirable to 
achieve the stopping distances contemplated in 
development of the standard. The agency also 
proposed increases in permissible brake actuation 
times to promote optimum cycling of the anti- 
lock systems used by most manufacturers in meet- 
ing the stopping distances. At the same time, 
the agency denied the petitions of the American 
Trucking Associations (ATA) and Consolidated 
Freightways (Consolidated) for extension of the 
required stopping distances as necessary to elimi- 
nate the necessity of high-torque brakes and anti- 
lock systems, and for suspension in whole or part 
of the standard's requirements. The denials were 
based on NHTSA's view that increased direc- 
tional stability is critical to improvement of brake 
system performance on heavy vehicles, particu- 
larly articulated vehicles, that share the highway 
with passenger cars and other light vehicles. 



Vehicle manufacturers and component sup- 
pliers supported without exception the increase 
in stopping distances. Additional discussions 
and data submitted by some manufacturers in- 
dicate that substantial effort is being made to 
identify and control all of the variables which 
affect compliance of air-braked vehicles with 
Standard No. 121. Most manufacturers recom- 
mended that the proposed extended distances be 
made permanent, but the NHTSA concludes that 
insufficient data exist at this time on which to 
base such a decision. Accordingly, the stopping 
distances are modified as proposed for a period 
that ends January 1, 1978. The NHTSA does 
not, therefore, accept the recommendations of 
Freightliner and Mack for longer distances, or 
the Freightliner recommendation for testing at 
55 mph. 

The proposed language has been modified to 
specify correctly the NHTSA's intent to extend 
service brake stopping distances on a skid number 
75 surface for all vehicles under S5.3.1.2 and 
S5.3.1.3. Also, the additional sentence proposed 
for S5.3.1.3 was essentially redundant in view 
of the modifications to Table Ila, and that sen- 
tence has been deleted. 

Manufacturers also supported the proposed 
increase in permissible brake actuation timing 
from 0.35 to 0.40 seconds for trucks and buses, 
from 0.25 to 0.35 seconds for trailer converter 
dollies, and from 0.25 to 0.30 seconds for trailers 
other than trailer converter dollies. The ATA 
i-ecommended establishment of a minimum as 
well as maximum limit. While this suggestion 
may have merit, the NHTSA does not have suf- 
ficient time at this point to fully consider the 
suggestion, and will therefore treat it as a peti- 
tion for rulemaking. 



PART 571; S 121— PRE 57 



Effective: August 27, 1975 



Bendix supjjested that tlie increased actuation 
be permitted only for an interim period, bnt the 
NHTSA has evidence of dejrraded performance 
fienerated by tlie present timinf; which justifies 
a permanent chanpe. Bendix is requested to sub- 
mit any data for consideration that support its 
view that superior systems will exist by January 
1, 1978, that provide both a faster and smoother 
response. 

Freiphtliner Corporation repeated its view that 
actuation and release times are desijjn-restrictive 
without correspondinff safety benefit. While the 
NHTSA is willin*; to consider Freifrhtliner's 
view for future action, it is noted that the ATA 
sufjpestion of mininnun and maximum limits 
conflicts directly with Freightliner's point of 
view. In any case, elimination of these require- 
ments was not contemplated by the scope of the 
proposal and will not be undertaken at this time. 

Several manufacturers indicated that the peti- 
tions for lonnjer actuation time implied the need 
for an increase in brake release times as well. 
Wliite Motor Corporation supplied data sub- 
stantiating: the view that optimization of in- 
creased brake actuation times depends in part 
on design freedom to increase the release time 
in the necessary valvinjj. Althou<jh increased re- 
lease times were not proposed by the Jime notice, 
an increase in release times comparable to actua- 
tion times was contemplated by the intent of the 
modifications to permit somewhat slower valve 
action. To accomplish the intended revision, the 
NHTSA concludes that it is in the public interest 
to modify both the actuation and release time 
of S5.3.3 and S5.3.4 by an increase in permis- 
sible timing of 0.05 seconds. Fruehauf's sujr- 
gested increase in trailer timino; to O.&R will be 
further considered, but the NHTSA does not 
believe it necessary to act on this level of increase 
without benefit of comments by interested persons. 

The ATA, Consolidated, the Milk Industry 
Foundation, and Hackney Brothers submitted 
arguments that the stopping distance and brake 
timing modifications were insufficient to solve 
fundamental cost and reliability problems attri- 
buted by them to Standard No. 121. The ATA 
cited recall campaigns of antilock systems as 
evidence that the presence of high-torque front 
brakes on some trucks creates safety problems 
in the event of antilock malfunction. The ATA 



also asserted that "no lockup" performance on 
trailers contributes insignificantly to highway 
safety, and asked that antilock, if mandated, be 
required only on a vehicle's drive axles. 

Consolidated relied on a manufacturer's state- 
ments of vehicle instability with the 121 brake 
systems as a ground for suspension of the stand- 
ard. The company also cited cost estimates for 
the standard, and requested that they be sub- 
stantially reduced by dropping the "no lockup" 
requirement entirely, or requiring it only on the 
vehicle's drive axles, and by extending stopping 
distances to eliminate the requirement for front 
axle 121-type brakes. 

The NHTSA has undertaken an extensive 
evaluation of the standard's effect on truck brak- 
ing characteristics. One element of that evalua- 
tion is testing by the NHTSA's Safety Research 
Laboratory of pre-121 and 121-equipped truck 
tractors. One series of tests (on a dry surface 
with a skid number somewhat higher than 75) 
included a stop from 60.8 mph in 231.2 feet by 
a 121-equipped International Harvester tractor 
(with front axle antilock disconnected and a full 
brake application) and a 121-equipped trailer 
in which the front wheel brakes never locked up. 
This experience indicates that 121-type front 
brake package need not be so aggressive as to 
create a safety hazard in the event of an antilock 
malfunction which escapes the notice of the 
driver. 

The NHTSA's monitoring of the standard's 
implementation also supports NHTSA's position 
that the malfunctions experienced in initial anti- 
lock production and installation are an inevitable 
consequence of the introduction of a new system 
in high production. Those malfimctions that 
have been determined to be safety-related and 
that could result in unsafe highway operation 
have been recalled for remedy by the manufac- 
turers concerned. 

The NHTSA has evaluated Consolidated's re- 
vised cost objections to the standard. The in- 
formation submitted does not modify the 
NHTSA's earlier conclusions. Accordingly, the 
NHTSA reaffirms its decisions not to revise or 
revoke the standard as requested by the ATA, 
Consolidated, the Milk Industry Foundation, or 
Hackney Brothers. 



PART 571; S 121— PRE 58 



EffecHve: August 27, 1975 



Consolidated characterized its comments as 
both a petition for reconsideration and, in the 
alternative, as a petition to modify the standard. 
A petition for reconsideration may under 49 
CFR 553.35 be submitted in response to a "rule" 
issued by the agency, but the denial of a peti- 
tion is not itself a "rule" within the meaning of 
that section. Therefore Consolidated's "petition 
for reconsideration" is invalid. Considered in 
the alternative as a petition for rulemaking to 
modify the standard, the \HTSA denies the 
petition for the reasons noted. 

Other comments to the docket requested 
changes to the standard wliich the XHTSA will 
consider further but cannot dispose of at this 
time. The revisions in this notice must be issued 
prior to September 1, 1975, so tliat manufacturers 
are not required to meet the 245-foot stopping 
distance which becomes effective September 1, 
1975. The issues, in addition to others noted 
earlier, that will be further considered are: 

(1) Freightliner's request for deletion of the 
dynamometer requirements for the front axle; 

(2) PACCAR's request for modification of dyna- 
mometer requirements on the drive axles; and 

(3) several manufacturers' requests for a de- 
creased grade in the parking brake requirement. 
The NHTSA does not agree witli Freightliner 
that the test surface and control trailer specifica- 
tions are insufficiently objective, or that the wet 
surface and emergency brake stopping distances 
need to be increased. Testing by the NHTSA 
Safety Research Laboratory does not indicate a 
need to increase these distances. The agency will, 
of course, continue to evaluate any new data that 
indicate more objective specifications can be rea- 
sonably implemented, or that longer distances are 
advisable. 

The third proposal for modification of the 
standard was revision of the standard's appli- 
cability to exclude trailers with a GVWR of 
10,000 pounds or less, trailers with an unloaded 
vehicle weight that is not less than 95 percent 
of its GVWR, and any other vcliicle that has a 
maximum speed of 45 mph, an unloaded vehicle 
weight that is not less than 95 percent of its 
GV^VR, and no passenger-carrying capacity. 

No comments opposed the exclusion of trailers 
whose unloaded vehicle weight is not less than 



95 percent of the G\^VR, and the standard is 
accordingly amended to exclude this vehicle 
group. 

The State of California objected to exclusion 
of light trailers (GVWR of 10,000 pounds or 
less) on several grounds. Their comments point 
out that a light trailer built for low density 
loads can be dangerously overloaded. The State 
also cited that ease with which higher GVWR 
trailers could be derated in order to take advan- 
tage of the exclusion for lighter vehicles. Cali- 
fornia also noted the increased complexity of 
enforcement of the standard with added exclu- 
sions of this type. Altec Industries, which peti- 
tioned for the exclusion, argued that the exclusion 
siiould be broadened to 15,000 pounds GVWR. 
On balance, the NHTSA agrees with California 
that the exclusion might create more safety prob- 
lems than safety benefit. In view of this con- 
clusion, the agency has decided not to revise the 
standard's applicability in this respect. 

The NHTSA also proposed exclusion of ve- 
liicles with the following characteristics: a speed 
attainable in 2 miles of not more than 45 mph, 
an unloaded vehicle weight that is not less than 
95 percent of tiie vehicle GVWR, and no pas- 
senger-carrying capacity. Manufacturers of those 
vehicles generally supported the proposal but 
expressed confusion over each of the criteria. 
The largest question arose over the meaning of 
what constitutes the "unloaded vehicle weight." 
Crane Carrier, FMC Corporation, The Heavy 
Specialized Carriers Conference (HSCC), and 
Koehring pointed to the significant difference 
between the GVAVR and the actual traveling 
weight of crane carrier models, considering 
special equipment which may or may not be in- 
cluded with the vehicle as optional or be per- 
mitted on the vehicle in transit. 

The NHTSA lias expressed the unloaded ve- 
liicle weight criterion in terms defined in § 571.3 
of its regulations (49 CFR §571.3) in a way 
wliich avoids these problems raised by the manu- 
facturers. As defined, "unloaded vehicle weight" 
will normally be the GVWR of a vehicle minus 
its rated cargo load and its assigned occupant 
weight (at least 150 pounds). The rated cargo 
load would not include the weight of portions 
of a vehicle wliich are essential to its specialized 



PART 571; S 121— PRE 59 



EffacHva: August 27, 1975 



function whether or not they are removed in 
accordance with State refjulation for transit pur- 
poses. To arrive at "unloaded vehicle weight," 
a manufacturer must only refer to the GVWR 
he has assigned to liis vehicle, and subtract from 
it the rated cargo load he has assigned plus 150 
pounds of each occupant position. These calcula- 
tions are totally separate from the presence of 
particular optional equipment or necessary com- 
ponents which may or may not be removed foi' 
highway travel. 

Manufacturers and the HSCC also asked 
whether occupant positions for crew members 
such as flagman or crane operator could be pro- 
vided without constituting "passenger-carrying 
capacity." The NHTSA uses the word pas- 
senger in this context to mean a person who does 
not help to operate the vehicle or its equipment, 
i.e., who is not part of an operating crew. Posi- 
tions for the crew necessary to operate a vehicle's 
specialized equipment would not disqualify a 
vehicle under the passenger-carrying criterion. 

Manufacturers recommended that the speed 
limitation of 45 mph be raised to 50 mph to allow 
unrestricted travel on all highway systems. The 
NHTSA remains convinced that this equipment 
with a high center of gravity and limited brak- 
ing poses a safety problem when traveling at 
near highway speed in the flow of traffic. With 
the national speed limit at 55 mph, it is con- 
sidered prudent to limit the speed of air-braked 
vehicles without 121 brake systems to a maxi- 
mum attainable speed of 45 mph. For the benefit 
of the HSCC, it is noted that the definition of 
maximum attainable speed specifies a level sur- 
face for the basis of speed determination. 



With regard to these vehicles, American-Cole- 
man Company has requested that all vehicles 
equipped with a front steerable drive axle of 
8,000 pounds GVWR or more be excluded from 
the requirements qf Standard No. 121. The 
NHTSA has already fully considered this re- 
quest, and in a series of notices (30 FR 40168, 
November 14, 1974; 40 FR 4153, January 28, 
1975; 40 FR 8953, March 4, 1975), explained its 
reasons for not proposing such an exclusion. 
American-Coleman's petition is repetitious of its 
earlier petition and contains no new data for 
consideration. Accordingly, it is denied. 

In consideration of the foregoing. Standard 
No. 121 (49 CFR 571.121) is amended. . . . 

Effective date : August 27, 1975. Because these 
amendments do not impose additional require- 
ments on any person and because they must re- 
place provisions effective September 1, 1975, it 
is found for good cause shown to be in the public 
interest that they become effective sooner than 
30 days following publication in the Federal 
Register. 

(Sec. 103, 119, Pub. L. 89-563, 30 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR 1.51.) 

Issued on August 15, 1975. 



Robert L. Carter 
Acting Administrator 

40 F.R. 38160 
August 27, 1975 



PART 571; S 121— PRE 60 



Effective: December 5, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No.' 75-7; Notice 3) 



This notice amends Standard No. 121, Ai)' 
Brake Systems, 49 CFR 571.121, to permit bulk 
agricultural commodity trailers designed witli a 
high ground clearance and other special features 
for use with farm tractors during harvests to 
meet emergency and parking bi'ake requirements 
other than those specified in S5.6 and So. 8 of the 
standard. 

This amendment follows reevaluation of a peti- 
tion filed by Utility Trailer Manufacturing Com- 
pany, in light of further data submitted by the 
company on August 6. 1975, and September 23, 
1975 (these materials appear in NHTSA Docket 
No. 75-5). The NHTSA proposed to exclude 
certain specialized agricultural trailers from the 
emergency and parking brake requiiements be- 
cause "spring" brakes utilized for these systems 
were creating particular difficulty in harvest op- 
erations (40 FR 13316, March 26, 1975). Com- 
ments persuaded the agency not to proceed with 
the proposal at that time for two reasons (40 
FR 28097, July 3, 1975). It appeared that con- 
trol of air leakage and the installation of a 
manual parking brake control would permit dis- 
engagement in most cases, and that manual 
release and application would serve in the in- 
stances when all air had leaked away. The 
second reason to withdraw the proposal was that 
the excluded category was not defined well 
enough to limit the extent of the exclusion. 

Utility has since supplied information indicat- 
ing that air leakage cannot be controlled suf- 
ficiently to rely on it for the release of spring 
parking brakes under the specialized conditions 
of harvest operations. More significantly. Utility 
reports that inexperienced persons who itiechani- 
cally release the spring brakes often fail to re- 
engage them for highway operation, permitting 



the trailer to operate on the highway without a 
secondary means of braking. 

With regard to the agency's concern that 
manufacturers supplying spring brakes to meet 
the standard would be placed at a competitive 
disadvantage by the exclusion, utility indicates 
that the manufacturers of the specialized trailers 
in question would approve of a parking and 
emergency braking system other than spring 
brakes. The competitive disadvantage would 
actually have occurred only with those highway 
trailers that were unintentionally included in the 
overly broad proposed definition. 

With the newly submitted information in mind, 
the NHTSA has decided to issue the proposed 
exclusion, but in a more limited form than pro- 
posed. To limit the effect of this amendment 
to those trailers for which it is intended, the 
proposed definition is modified to describe more 
precisely trailers that are actually disconnected 
from liighway truck-tractors and drawn through 
the fields as part of their function. 

As discussed in the preamble to the proposal, 
the exclusion would have entirely excluded the 
trailers from the standard's emergency and park- 
ing brake requirements, relying on Bureau of 
Motor Carrier Safety Regulations to ensure the 
use of a "breakaway" system in their place. It 
is now apparent, however, that many of the ve- 
hicles in question would operate intrastate only, 
and that the breadth of the proposal must be 
somewhat restricted, to exclude only vehicles that 
are fitted with a breakaway system that complies 
with BMCS requirements. 

In order to permit manufacturers of these 
specialized vehicles to commence manufacture for 
the 1976 harvest season, the NHTSA has decided 
to extend the duration of the limited exclusion 



PART 571; S 121— PRE 61 



EfFective: December 5, 1975 

from the proposed date of January 1, 1976, to that an immediate effective date is in the public 

March 1, 1976. Utility requested that the date interest. 

be extended to June 30, 1976, and the NHTSA (gee. 103, 119, Pub. L. 89-563, 80 Stat. 718 

will issue a further proposal if any further delay (15 U.S.C. 1392, 1407) ; delegation of authority 

of this magnitude appears justified. at 49 CFR 1.51.) 

In consideration of the foregoing, S5.6 and j^^^^^ ^^ November 28, 1975. 
S5.8 of Standard No. 121 (49 CFR 571.121) are 
amended. ... 

Effective date : December 5, 1975. Because this . 1 • ■ ' 

J .1 , , 1 Ti.- 1 • Admmistrator 

amendment does not place additional require- 
ments on any person, and because manufacturers 

must be informed of future requirements for 40 F.R. 56898 

their products, it is found for good cause shown December 5, 1975 



PART 571; S 121— PRE 62 



Effective: January 6, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 

(Docket No. 75-16; Notice 6) 



This notice amends Standard No. 121, Air 
Brake Systems, to suspend until January 1, 1977, 
the service brake stopping distance requirements 
as they apply to buses. 

The NHTSA proposed a 1-year suspension of 
service brake stopping distances (40 FR 52856, 
November 13, 1975) following a public meeting 
on Standard No. 121 (49 CFR 571.121). Bus 
performance was I'eviewed by manufacturers and 
users, and by Rockwell International Corpora- 
tion, presently the manufacturer of most of the 
axles and antilock components installed in transit 
and intercity buses. Other data collected by the 
NHTSA substantiate a pattern of erratic be- 
havior in bus antilock equipment used in most 
transit and intercity operation that warrants dis- 
connection while a correction is fully developed. 
The proposed suspension was based on manu- 
facturer and user requests for a period in which 
modified hardware could be field-evaluated along 
with other antilock systems being offered for bus 
applications. 

The comments uniformly supported the pro- 
posed suspension of service brake stopping dis- 
tance requirements (including the "no lockup" 
requirement) for transit and intercity buses. 
However, component suppliers, bus manufac- 
turers, and bus users differed over the extent 
of the proposal in three areas. 

Rockwell and General Motors expressed con- 
cern that the preamble to the proposal had not 
made clear whether the proposal was intended 
to meet problems other than erratic antilock per- 
formance. Transport of New Jersey also objected 
that the proposal might be narrowly construed 
to mean that only the "no lockup" aspect of the 
stopping distance requirements would be sus- 
pended. AM General questioned whether the 



revision included "any attempt to impose stop- 
ping distance and lane limit test requirements." 

The NHTSA proposed suspension of the serv- 
ice brake stopping distance requirements (S5.3.1) 
in their entirety, not just the "no lockup" re- 
quirements of the section. Suspension of the 
entire requirement was intended to moderate the 
maintenance and misadjustment problems that 
are associated with the faster wearing brake lin- 
ings provided in compliance with the standard. 

General Motors noted that, because of the 
unique configuration of the braking system on its 
new transit bus, the limited nature of the 
NHTSA's proposed suspension, specifically the 
continuation of the partial system failure require- 
ments, inadvertently prevents their bus from 
utilizing the lower-coefficient linings intended by 
the proposal. This issue is presently under con- 
sideration by the agency, and may be the subject 
of another proposal to be issued shortly. 

The second area of concern to some manufac- 
turers was whether the NHTSA intended to 
cover school buses with the proposed exclusion. 
General Motors and AVagner Electric Corpora- 
tion expressed the view that school buses should 
not be included. International Harvester, Crown 
Coach, and several school districts believed that 
the vehicles should be included in the suspen- 
sion. The NHTSA intended to include school 
buses in its proposal and, based on review of the 
comments, has concluded that these buses should 
be included in the suspension. 

International Harvester pointed out that the 
stop-and-go cycle of school buses can cause dis- 
tinctive stresses on the air brake system that 
are similar to that encountered in transit bus 
operation. While not made explicit. Crown 
Coach's comments illustrate that some school 



PART 571; S 121— PRE 63 



Effective: January 6, 1976 



buses utilize the same axles and antilock com- 
ponent as transit and intercity buses. Limiting 
the suspension to a portion of the air-braked 
sclaool buses would create an unintended economic 
disadvantage for some school buses of this type. 
Wagner and General Motors argued that some 
school buses utilize truck chassis and brake sys- 
tems, and that these systems do not suffer from 
the same problems as the bus components criti- 
cized at the public meeting. It is true that the 
components utilized generally in trucks and also 
used in some buses have been determined to be 
reliable (40 FR 59222, December 22, 1975). The 
usage cycles of various vehicles are, however, 
evidently an important factor in some of the 
problems that have been experienced. Consider- 
ing the similarity in the usage of school buses 
to that of transit buses, this agency has decided 
that the most desirable course of action is to 
include school buses in the suspension of stopping 
distance requirements. 

The third area in which commenters ques- 
tioned the extent of the proposal was the length 
of the suspension. Bus operators and their 
associations {e.g.^ National Association of Motor 
Bus Owners (NAMBO), American Public 
Transit Association (APTA), Chicago Transit 
Authority) and bus manufacturers (General 
Motors, AM General, and Eagle International) 
generally argued that a 1-year evaluation period 
following development of adequate corrections to 
existing or new liardware would be necessary. 
Motor Coach Industries and Transportation 
Manufacturing Corporation (manufacturers of 
the majority of intercity buses) supported the 
1-year proposal without commenting on tlie ade- 
quacy of the proposed 1-year suspension period. 
Rockwell, as the present manufacturer of most of 
the transit and intercity bus axles and antilock 
systems, cautioned the NHTSA that a specific 
date for the effectiveness of S5.3.1 would reduce 
the thoroughness of the evaluation program. The 
company did support the 1-year suspension. 

The proposal was for a 1-year suspension only. 
This agency has not found this to be an emer- 
gency situation that would justify pronmlgating 
a delay greater than that proposed without the 
benefit of notice and opportunity to comment. 
Therefore, the NHTSA hereby makes final its 
proposed 1-year suspension of the stopping dis- 



tance requirements, and will further evaluate the 
requests for a longer period of suspension. Bus 
manufacturers have stated that they intend to 
initiate field evaluation of improved antilock 
systems, and this agency will actively monitor 
these efforts as the basis for future action. The 
support of field testing by NAMBO and APTA 
will also be important in making meaningful 
evaluations of anticipated system modifications. 

Chrysler, Freightliner, and International Har- 
vester recommendations on other aspects of the 
standard and its applicability to other vehicle 
types have been responded to in the NHTSA's 
recent proposal for modification of the standard's 
performance levels for trucks, buses and trailers 
(40 FR 59222, December 22, 1975). 

AM General asked whether buses manufac- 
tured during the suspension could be required 
to be retrofitted in the future. The answer is 
no. The motor vehicle safety standards in effect 
at any date apply according to their terms only 
to vehicles manufactured on that date. In an- 
swer to AM General's question whether the anti- 
lock system on 121-equipped buses may "be 
completely deactivated and dismantled and the 
vehicle returned to the pre-FMVSS #121 
status," it is the position of the NHTSA that 
manufacturers and operators are the persons qual- 
ified and required to determine the safest con- 
figuration for operation of their veliicles, subject 
to applicable Bureau of Motor Carrier Safety 
regulations. With regard to the effect of Federal 
law on the modification of safety systems, a 
manufacturer of air-braked buses that conform 
to the air brake standard may instruct the owners 
of its products to disconnect the antilock system 
used to meet the standard, for the period neces- 
sary to correct a safety-related defect in the sys- 
tem that may make its operation hazardous. 

It is also noted that this amendment constitutes 
the NHTSA's favorable response to APTA's 
October 6, 1975, request for modification of the 
standard, and the October 22, 1975, petition of 
the Eastern Bus Maintenance Men's Conference 
concerning Standard No. 121. 

In consideration of the foregoing, S5.3.1 of 
Standard No. 121 (49 CFR 571.121) is amended 
by the addition of the phrase "Except for a bus 
manufactured before January 1, 1977, and" at the 
beginning of tlie first sentence. 



PART 571; 8 121— PRE 64 



Effective: January 6, 1976 

Effective date : January 6, 1976. Because this Issued on January 6, 1976. 

amendment represents a relaxation of the require- 
ments of the standard and does not place addi- 
tional requirements on any person, it is found James B. Gregory 
for good cause shown that an immediate effective Administrator 
date is in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(14 U.S.C. 1392, 1407) ; delegation of authority 41 F.R. 1598 

at 49 CFR 1.50.) January 9, 1976 



PART 571; S 121— PRE 65-66 



Effective: February 26, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

(Docket No. 75-5; Notice 5) 
Air Brake Systems 



This notica amends Standard No. 121, Air 
Brake Systems, by extending until June 30, 1976, 
the period in wliich bulk agricultural commodity 
trailers designed with a high ground clearance 
and other special features for use with farm 
tractors during harvest can meet emergency and 
parking brake requirements other than those 
specified in S5.6 and S5.8 of the standard. 

Standard No. 121, 49 CFR 571.121, presently 
permits this specialized agricultural trailer cate- 
gory the option, until March 1, 1976, of meeting 
the parking brake requirements of the standard 
(actuation by an energy source unaffected by air 
loss in the service brake system) or the air- 
actuated "breakaway" system that complies with 
Bureau of Motor Carrier Safety requirements 
(49 CFR §393.43). The NHTSA proposed ex- 
tension of the March date to June 30, 1976 (41 
FR 1763, January 12, 1976) to permit completion 
of the bulk agricultural commodity trailers nec- 
essary for the 1976 harvest season, in response to 
a petition of the Utility Trailer Manufacturing 
Company. In a separate action, the NHTSA 
has also proposed that the present parking brake 
requirements for all vehicles subject to the stand- 
ard be broadened in a closely similar fashion to 
permit the use of an air energy source, with 
single diaphragm brake chambers as well as dual 
diaphragm brake chambers for actuation of the 
parking brake (40 FR 56920, December 5, 1975). 
It is clear, however, that separate and swifter 
action than the general proposal is necessary to 
permit the manufacture of trailers for the 1976 
harvest. 

Utility Trailer Manufacturing Company sup- 
ported the extension of the period to June 30, 
1976, and advocated extension of the option to 
all other air-braked vehicles. Wesco Truck and 



Trailer Sales (Wesco) also supported the pro- 
posal and suggested that a 2-year suspension of 
the standard would permit perfection of the new 
brake systems. Wesco recommended that the 
parking brake system be made optional on this 
type of agricultural trailer. Fruehauf Corpora- 
tion supported the proposal without qualification. 

In view of the comments received and the 
NHTSA's continued view that the special con- 
siderations for in-field use should be given to 
agricultural trailers with regard to parking 
brake requirements, the agency has decided to 
amend the standard as proposed. The other rec- 
ommendations by Utility and Wesco are noted, 
but they do not fall within the limits of action 
proposed by the NHTSA. 

In consideration of the foregoing, the last sen- 
tences of paragraphs S5.6 and S5.8 of Standard 
No. 121 (49 CFR 571.121) are amended by 
changing the date "March 1, 1976" to "June 30, 
1976." 

Effective date: February 26, 1976. Because 
this amendment creates no additional require- 
ments for any person, and because trailer manu- 
facturers need to know the extent of the option 
period as the basis for planning manufacturing 
schedules, an immediate effective date is found 
to be in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR 1.50.) 

Issued on February 20, 1976. 

James B. Gregory 
Administrator 

41 F.R. 8347 
February 26, 1976 



PART 571; S 121— PRE 67-68 



Effective: February 26, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 7) 



This notice amends Standard No. 121, Air 
Brake Systems, to establish bi-ake performance 
levels that are less stringent than existing levels. 
The amendments also affect towing vehicle per- 
formance and the effective date of the standard 
for certain categories of specialized vehicles. 

The National Highway Traffic Safety Admin- 
istration (NHTSA) proposed these modifications 
(40 FK 59222, December 22, 1975) in response to 
information developed at an October 1975 public 
meeting and other information collected by the 
NHTSA on field experience with implementation 
of Standard No. 121 (49 CFR 571.121). The 
proposal also responded to requests from Freight - 
liner Corporation, PACCAR Corporation, "White 
Motor Corporation, and the American Trucking 
Association (ATA). 

CONSIDERATIONS UNDERLYING 
THE STANDARD 

Under the National Traffic and Motor Vehicle 
Safety Act, as amended (the Act) (15 U.S.C. 
§ 1381 et seq.), the Department of Transportation 
is responsible for the issuance of motor vehicle 
safety standards that, among other things, pro- 
tect the public against unreasonable risk of acci- 
dents occurring as a result of the design, 
construction, or performance of motor vehicles. 
The Act directs the agency to consider whether 
a standard would contribute to carrying out the 
purposes of the Act and would be reasonable, 
practicable, and appropriate for a particular 
type of motor vehicle. 15 U.S.C. 1392(f)(3). 
The standard must, as formulated, be practicable, 
meet the need for motor vehicle safety, and be 
stated in objective terms. 15 U.S.C. 1392(a). 
The Senate Committee drafting the Statute 
stated that safety would be the overriding con- 



sideration in the issuance of standards. S. Rep. 
No. 1301, 89th Cong., 2d Sess. (1966) at 6. 

Vehicles equipped with air brakes figure prom- 
inently in the highway safety hazards addressed 
by the Act. The National Safety Council (NSC) 
reports that more than 700,000 air-braked vehicle 
accidents, causing over 5,000 deaths, occur each 
year. Accident Facts 56 (1975). Accident 
figures show that heavy truck-trailer coml^ina- 
tions are extremely hazardous to other highway 
users, and have a disproportionate involvement 
in fatal accidents. Accident Facts 56 (1975). 
Not only is tlieir exposure greater because of the 
higher average mileage traveled, but they actually 
have a nuich higher rate of fatal accidents per 
vehicle mile, as shown by the preliminary report 
in a recent study by the Highway Safety Re- 
search Institute. ''Highway Safety Effects of 
Energy Crisis on U.S. Toll Roads" (NHTSA 
contract in process at Highway Safety Research 
Institute). The NSC reports that the rate of 
involvement per vehicle in fatal accidents by 
truck-trailer combinations is nine times greater 
than the involvement by passenger cars. The 
fatality rate of heavy truck-to-car accidents is 
fourteen times greater than that of car-to-car 
accidents. "Truck Accidents in North Carolina," 
Highway Safety Highlights, Highway Safety 
Research Center, U. of N. Carolina (May 1975). 
Approximately 35 occupants of passenger cars 
are killed for every occupant of a heavy truck 
who loses his life in truck collisions with pas- 
senger cars on the interstate system. Truck 
Accidents and Highway Safety — An Overview 6 
(1968) ; National Transportation Safety Board, 
Special Study, Com/mercial Motor Vehicle Brak- 
ing 2 (Nov. 1972). Indeed, there are some indi- 
cations that the involvement rate in accidents by 



PART 571: S 121— PRE 69 



EfFeclive: February 26, 1976 



truck-trailer combinations is increasing. "High- 
way Safety Effects of Energy Crisis on U.S. Toll 
Koads" (in process). 

Faced with data showing the disproportionate 
hazards of heavy trucks on the highway, the 
National Highway Safety Bureau (predecessor 
agency to the NHTSA) initiated a program to 
improve the safety performance of these vehicles. 
There was no initial Federal motor vehicle 
safety standard applicable to air-braked trucks. 
At. the inception of the regulatory development 
program, the agency solicited comments on sev- 
eral aspects of commercial vehicle safety (32 FR 
14278, October 14, 1967) including brake systems, 
tires, and rear-underride protection. The engi- 
neering staff consulted with representatives of 
the heavy motor vehicle industry, reviewed 
existing data and literature, and issued several 
contracts to investigate the nature of the large 
vehicle safety problem. An advance notice of 
proposed rulemaking on coupled vehicle stability 
and control was issued in 1969 (34 FR 1055, 
January 23, 1969) to solicit the views of the 
industry and other interested parties on the 
means to reduce the number and severity of 
heavy vehicle accidents. 

The determination of motor vehicle accident 
causation has been hampered by two basic diffi- 
culties. First is the absence of a representative 
broad-based body of highway accident data of 
sufficient detail to permit accurate discrimination 
of accident causation effects. Second is the un- 
developed state of causation analysis methodol- 
ogy. Even if complete accident data were 
available, existing methodology provides no ob- 
jective basis for quantitatively assessing the de- 
gree to which any prospective countermeasure 
would reduce the number or severity of crashes. 
The agency, therefore, had to rely on qualitative 
analysis, by its own and other researchers, of the 
limited available accident data on heavy vehicles. 

Available evidence indicates that, relative to 
the lighter passenger cars sharing the highway, 
inferior braking and poor vehicle control of 
trucks during braking and turning maneuvers 
are substantial causes of heavy vehicle involve- 
ment in accidents. At the time the NHTSA first 
studied the problem, existing braking character- 
istics and performance of passenger cars and 
heavy trucks varied dramatically. Trucks gen- 



erally are much heavier than passenger cars, have 
a higher center-of-gravity, and tlie axle-by-axle 
loads on trucks vary sharply between the loaded 
and unloaded conditions. Bm, TrucTc^ Tractor- 
Trailer Braking System Performance 1, High- 
way Safety Research Institute, U. of Michigan 
(1971). Passenger cars' braking distances from 
60 mph on a dry surface reported to NHTSA in 
1975 by vehicle manufacturers range from 165 to 
225 feet. Brakes, a Comparison of Braking 
Performance for 1975 Passenger Cars anxl Motm'- 
cycles. Truck-trailer combinations have average 
capabilities of approximately 300- to 350-foot 
stops under similar conditions, although some of 
the poorer-performing combinations take as much 
as 450 feet to stop from 60 mph. Bm, Truck, 
Tractor-Trailer Braking System Performance. 
Even the worst of these truck brake systems pre- 
sumably met the only Federal braking require- 
ments in effect at the time, those of the Bureau 
of Motor Carrier Safety (BMCS), which im- 
posed requirements for stops from 20 mph. 49 
CFR § 393.52. 

Federal Highway Administration statistics 
demonstrate that, in rear-end collisions on the \ 
interstate system, vehicle types with the longest 
average stopping distances are also the vehicles 
with the highest rate of involvement in fatal 
accidents. Public Roads 1969 Figure 9, and 
Public Roads 1966 Figure 8. One study shows 
that, of 453 accidents involving one or more ve- 
hicles, more than three-fourths involved skidding, 
and loss of control occurred following applica- 
tion of the brakes in more than half of them. 
The Importance of Loss of Directional Control | 
in Car Accidents, G. Grime (June 1963). 
NHTSA evaluation of BMCS statistics on se- 
lected major accidents of regulated carriers indi- 
cates that accidents involving "jackknifing" or 
other skidding, and collisions into the rear-end 
of vehicles, or into slowly moving or stopped 
vehicles, could often be reduced in severity or 
avoided altogether by improved vehicle stability 
and braking. This conclusion is supported by 
the National Transportation Safety Board, an 
independent agency that investigates major 
transportation accidents. Special Study — Coin- 
mercial Vehicle Braking 2 (November 1972). 
Independent researchers in State highway fatal- 
ity statistics also conclude that improved braking 



PART 571; S 121— PRE 70 



Effective: February 26, 1976 



and handling for truck-trailer combinations 
would improve overall highway safety. Lohman 
and Waller, "Trucks: An Analysis of Accident 
Characteristics by Vehicle Weight," U. of N. 
Carolina (September 1975) ; Baker, Wong, and 
Masemore, "Fatal Tractor Trailer Crashes : Con- 
siderations in Setting Relevant Standards" (July 
1965). 

Numerous research studies have investigated 
the questions of improved stability of heavy 
motor vehicles, particularly truck-trailer combi- 
nations, e.g., "The Handling and Stability of 
Articulated Vehicles under Braking Conditions," 
F. D. Hales, et al. (January 1966). It is a uni- 
versally accepted principle of vehicle dynamics 
that a prerequisite to the maintenance of stability 
and directional control of any automotive vehicle 
is that its tires continue rolling. A tire on a 
locked wheel can generate no lateral forces to 
affect its direction of motion. A vehicle whose 
wheels are locked is likely to slide sidewards as a 
result of such conditions as unevenness or bank- 
ing in the road surface, wind forces, impacts on 
or by another vehicle or steering inputs by the 
driver as a result either of the emergency situa- 
tion or of curves, e.g., R.D. Lister, "Retention 
of Directional Control When Braking," SAE 
Paper 963A (January 1965) ; "Measurement of 
Vehicle Response in Severe Braking and Steer- 
ing Maneuvers," Dugoff, et al., SAE Paper 
710080 (January 1971). 

Consultation with the truck manufacturing 
and user industry, and a major research contract 
on heavy vehicles for the agency, demonstrated 
that improved systems were available to increase 
heavy vehicle stopping control. Truck, Bus, 
Tractor-Trailer Braking System Performance, 
U. of Michigan (1971). Improved fade resist- 
ance,, improved actuation and release times, 
greater air reservoir capacity, and partial failure 
performance are elements of such improved 
braking. Most important were more effective 
brakes to rediice the disparity in stopping capa- 
bilities between passenger cars and heavy vehicles, 
and provision against wheel lockup during brak- 
ing in order to prevent the vehicle from skidding 
out of control. The ATA, in its comments on 
the 1967 notice concerning truck braking, recom- 
mended that consideration be given to "anti- 
locking brake devices." See NHTSA public 



docket. Comments received in response to the 
agency's 1969 notice on coupled vehicle stability 
and control confirmed that better brake perform- 
ance was possible and that various devices to 
reduce chances of wheel lockup were available. 
Meetings with an "outside task force" of inter- 
ested industry representatives and with indi- 
vidual manufacturers also showed the technical 
feasibility of improved braking systems. 

In view of the available technology to improve 
heavy vehicle braking and vehicle control, and 
the over-involvement of air-braked vehicles in 
highway crashes that could be avoided or reduced 
in severity by better braking and vehicle control 
systems, the NHSB in 1970 proposed braking 
performance standards for air-braked trucks, 
buses, and trailers. The agency action was also 
motivated by the attempts to increase permissible 
size and weight of commercial vehicles on the 
interstate highway system (a weight increase to 
80,000 pounds gross vehicle weight rating has 
occurred since proposal and implementation of 
the standard). Standard No. 121 was issued in 
February 1971, and was implemented for trailers 
on Januai-y 1, 1975. and for trucks and buses on 
March 1, 1975. 

Although the standard involves numerous as- 
pects of air brake systems, the most important 
and controversial provisions of the standard are 
those that require improved stopping capability 
and "no lockup" performance. Section S5.3.1 
specifies stopping in limited distances from 20 
and 60 mph, in the loaded and unloaded condi- 
tions on wet and dry surfaces, with the vehicle 
remaining in a 12-foot-wide lane and with limits 
on wheel lockup. It is the stopping limits and 
"no lockup" requirements that are the source of 
the basic issues concerning the standard. 

Tlie agency established a stopping distance re- 
quirement of 245 feet from 60 mph on a dry- 
surface with the vehicle loadeed. The stopping 
distance of passenger cars under comparable con- 
ditions averaged approximately 200 feet, with 
many vehicles bettering that mark. By mandat- 
ing 245 feet as a minimum requirement, the 
standard improved the safety of air-braked ve- 
hicles in two ways. The minimum distance re- 
quirement placed a floor on stopping distance 
performance and eliminated the vehicles that 



PART 571; S 121— PRE 71 



Effective: February 26, 1976 



were built with extremely Ion": stoppinj; dis- 
tances. More impoi'tantly, it mandated a sub- 
stantial reduction in the dispai'ity of brakinjj; 
performance between passenjier cars and heavy 
vehicles as a whole. 

"WHiile all elements of tlic industry supported 
the principle of minimum stopping distance re- 
quirements for air-braked vehicles, questions 
arose followinji issuance of the standard and be- 
fore implementation as to the technolopfical 
feasibility for mass-produced vehicles of the 
level set in the standard. The Act requires that 
safety standards be "practicable.'' 

The basic NHTSA contract and other test data 
underlyinj; the standard demonstrated that some 
pre-121 production vehicles already approximated 
the stoppinji distance requirement of 24.5 feet. 
But manufacturers that had stated they could 
provide the minimum stopping distance of 245 
feet discovered that the traditionally weak front 
axle brakes on many trucks would liave to be 
substantially upgraded, in some cases more than 
had originally been anticipated. Although the 
NHTSA implemented the standard with a 258- 
foot interim stopping distance to accommodate 
mass pi'oduction start-up problems, front axle 
brakes on some vehicles were still overdesigned. 
and for two basic reasons. The source of the 
problem was not technological unfeasibility of 
producing the desired handling characteristics, 
which are available in many 121-equipped ve- 
hicles produced since A[arch 1, 1075. Rather, it 
appears that some manufacturers sought to en- 
sure 100-percent compliance with the standard 
by concentrating on utilizing a few new axle and 
brake assemblies that were sufficiently aggressive 
to manage the braking force for an entire line of 
vehicles. In addition, the unanticipated degree 
of variability in performance of some mass- 
produced components forced larger "compliance 
margins" of over-performance, to assure that 
each vehicle produced would meet the minimmn 
performance level of the standard. 

The NHTSA responded to the evidence of ad- 
verse handling in some manufacturers" produc- 
tion by increasing stopping distances to 277 feet 
until January 1, 1978 (40 FR 38160, August 27, 
197a). This action was supported by manufac;- 
turers but failed to encourage sufficiently the 
"depowering" of front axle brakes. The agency 



therefore proposed new established values (not 
limited to an interim period) in a proposal dis- 
cussed in detail below. 

Thus, while the stopping distances established 
liy the standard have always been fully justified 
in safety need and technological feasibility, the 
agency has responded several times to evidence 
that some manufacturers were having difficulty 
in improving their worst-performing vehicles 
enough to satisfy the standard. The availability 
of mass-produced vehicles from some manufac- 
turers that meet the 245-foot requirement with- 
out adverse handling (see Docket 75-16; Notice 
02-125) demonstrates that the present proposed 
distance is undoubtedly achievable in advancing 
motor vehicle safety. 

The other major provision that has raised is- 
sues in implementation of the standard is the 
requirement limiting lockup of wheels during 
the stops mandated by the standard. As ex- 
plained earlier, the limitation on lockup is in- 
tended to increase the stability and directional 
control of heavy vehicles during braking and 
turning maneuvers. Most manufacturers utilize 
antilock systems to provide the required "no 
lockup'' performance, although other devices 
(such as load-sensitive proportioning devices) 
may be capable of providing the specified per- 
formance. The systems are installed to momen- 
tarily and automatically release the brakes to 
avoid skidding in cases where the brake applica- 
tion is so strong, or the road surface so slippery, 
that wheel lockup would normally occur. Some 
manufacturei's and users have reported that some 
of the antilock systems that have been installed 
do not function correctly and that malfunction 
makes 121-equipped vehicles less safe than pre- 
121 vehicles. These commenters argue that for 
this reason the standard does not meet the need 
for motor vehicle safety as specified in the Act. 

Standard No. 121 meets the need for motor 
vehicle safety by specifying "no lockup'' per- 
formance tliat increases directional stability and 
control of heavy motor vehicles to reduce their 
involvement in highway accidents. The decision 
by some manufacturers to choose a type of anti- 
lock that malfunctions or is not suited to their 
products does not mean that the standard fails 
to meet the need for motor vehicle safety. That 
conclusion could be drawn only if the safety 



PART 571; S 121— PRE 72 



Effective: February 26, 1976 



performance specified were not in fact practi- 
cable. The fact that thousands of vehicles have 
been manufactured with antilock systems that 
have not reported any safety-related defects 
clearly shows that the standard is practicable. 
The position that a manufacturer's failure to 
build a reliable product could of itself defeat the 
validity of a standard would place in the hands 
of the rejsnilated industry the decision to imple- 
ment, continue in effect, or cancel any safety 
standard. 

The NliTSA has monitored the test programs 
of antilock manufacturers to ensure that reliable 
oiTcfoTvio wprp intt'oduced. Proprietary data on 
antilock test programs are included in the ad- 
ministrative record of this standard. 

The XHTSA lias taken appropriate action in 
the case of antilock malfunction that poses a 
potential safety hazard. In cases where the mal- 
function has momentarily released the brakes 
under some circumstances when they should re- 
main applied, the agency has suspended the 
standard's requirements for a period to permit 
development of solutions to the design deficien- 
cies involved (41 FR 1598, January 9, 1976). 
Most antilock malfunctions simply cause the sys- 
tem to disable itself and return braking to nor- 
mal. Users have expressed the fear that, with 
disabled antilock, severe brake applications will 
cause wheel lockup and cause the vehicle to lose 
control and become a hazard on the highway. 
The XHTSA considers these fears unrealistic, 
because of the extremely limited cases in which 
the problem would arise. 

The circumstance where a 121-equipped vehicle 
is significantly more likely to lock up than a 
pre-121 vehicle is on the front axle because of the 
generally stronger brakes. But the possibility 
of this occurring is prevented at low pedal ap- 
plications by the provision of "automatic pres- 
sure limiting valves" that reduce or eliminate the 
brake pressure to the front axle during the great 
majority of brake applications. Also, a warning- 
signal on the instrument panel advises of antilock 
electrical failure and gives advance notice to the 
driver in all cases except the statistically rare 
occasions when antilock fails during a panic 
brake application. In view of the benefit, of 
functioning antilock and the extremely small 
chance that a driver would not be warned before 



use of the brakes in a panic stoi), the XHTSA 
evaluates the risk of malfunction as small and 
outweighed by the benefits of the antilock re- 
quirement. 

Many commenters at the October 1975 public 
meeting suggested that hundreds of reliability 
problems with safety consequences have occurred 
in antilock components used to meet the standard. 
The Act requires vehicle and equipment manu- 
facturers to report such safety-related defects 
that develop in their products, to the XHTSA 
and the agency has carefully monitored reports 
concerning antilock reliability. To date, only 
nine such safety-related defects have be^n re- 
ported, and the majority of them were limited to 
minor start-up problems in the mass-production 
process that were easily corrected. 

XOTICE 05 PROPOSAL 

Vehicles produfced to meet the standard are 
now in service and available for comprehensive 
evaluation. Reports on vehicle performance were 
received at a public meeting on implementation 
of the standard in October 1975. Other reports 
have been made directly to the agency. The 
XHTSA has been testing 121-equipped vehicles 
at its Safety Research Laboratory since produc- 
tion vehicles have become available. In Septem- 
ber 1975, the agency discussed implementation of 
tiie standard with all antilock manufacturers and 
several major vehicle manufacturers. 

The XHTSA has determined that some ve- 
hicles produced to comply with the standard 
demonstrate unsatisfactory handling character- 
istics. The source of the problem is not tech- 
nological unfeasibility of producing vehicles with 
desirable handling characteristics, as demon- 
strated by many of the 121-equipped vehicles 
produced since March 1, 1975. Rather (as noted 
earlier), it appears that some manufacturers 
sought to ensure 100-percent compliance with the 
standard by concentrating on utilizing a few new 
axle and brake assemblies that were sufficiently 
aggressive to manage the braking force for an 
entire line of vehicles. In addition, the unantici- 
pated degree of variability in performance of 
some mass-produced components forced larger 
"compliance margins," to assure that each vehicle 
produced would meet the minimum performance 
level of the standard. The brake imbalance that 



PART 571; S 121— PRE 73 



Effective: February 26, 1976 



exists in any braking system (due to production 
variations) is of course magnified as the brakes 
become more effective. 

"VVhile it would be possible to requii ■• redesign 
of the vehicles to eliminate these characteristics, 
the agency considers this course of action unduly 
costly in view of the economic situation of the 
heavy truck industry. Large sums have already 
been expended by vehicle manufacturers to 
achieve compliance with the standard. The 
agency has decided that it should instead reduce 
the performance levels of the standard somewhat 
to permit the "depowering" of the steering axle 
brakes sufficiently to improve handling char- 
acteristics while design problems are being re- 
solved by the manufacturers. 

The agency has evaluated the comments sub- 
mitted by vehicle manufacturers and users, 
equipment suppliers, the International Brother- 
hood of Teamsters, and the Commonwealth of 
Pennsylvania. The NHTSA concludes that the 
proposal should be made final as proposed, with 
only a few modifications. While commenters 
expressed differing views on what other modifi- 
cations of the standard might be beneficial to 
motor vehicle safety, they supported, with few 
exceptions, the proposed performance levels as a 
feasible technical level that would contribute to 
motor vehicle safety. A commonly expressed 
view was the need for stability in the perform- 
ance levels of the standard as the basis to get the 
truck industry back into a healtliy sales posture. 
Ford, for example, stated that it "trusts that the 
Administration will recognize the need to pro- 
ceed cautiously to avoid further disruptions of 
the heavy truck business." 

Because the comments generally agreed that 
the 293-foot stopping distance would accomplish 
the NHTSA's goal to permit depowering front 
axle brakes enough to eliminate handling prob- 
lems, the stopping distance requirement is 
amended as proposed. Freightliner Corporation, 
which petitioned for these stopping distances, 
noted, "The proposed loaded vehicle stopping 
distances provide a realistic basis for establishing 
minimum service brake stopping distance re- 
quirements." 

Oshkosh Truck Corporation disagreed with the 
proposed distances in the case of straight trucks. 



with the view that the problems raised at the 
October 1975 public meeting apply only to buses 
and tractor-trailer combinations. Oshkosh pointed 
to the adequacy of its brake systems and noted 
that the earlier increase in permissible stopping 
distances from 245 f^et to 277 feet should provide 
for any "compliance margin" for problems being 
experienced. 

The NHTSA does no* .jU"-:tion the superior 
handling characteristics oi Oshkosh vehicles, but 
acts from a concern over axle systems designed 
for the entire vehicle population, including many 
vehicles that are different from Oshkosh products. 
It is an unfortunate effect of i-educing the re- 
quirements for all vehicles that manufacturers 
of the better-designed vehicles, such as Oshkosh, 
may feel forced by commercial considerations to 
downgrade the braking abilities of their products. 

The Commonwealth of Pennsylvania, citing 
examples from its accident files of light vehicles 
being struck from the rear by lieavy trucks, ex- 
pressed strong concern over the proposal for an 
increased stopping distance. The NHTSA 
shares this concern. The countervailing consid- 
erations cited above lead to a reduction in the 
basic braking performance that has up to now 
been required by Standard 121. However, this 
agency has determined that the 293-foot mini- 
mum requirement, along with the many other 
requirements of the standard, will nevertheless 
substantially increase the braking capability of 
air-braked vehicles compared to that prevailing 
before the standard went into effect. The stand- 
ards also continue to prevent the manufacture of 
those 3-axle trucks that have grossly inferior 
braking capability. 

The International Brotherhood of Teamsters 
expressed continued support for the standard, 
urging more stringent performance levels in the 
future. As the proposal noted, far more infor- 
mation will be available in the future as the 
basis for further changes of the stopping distance 
performance levels, including the statistical eval- 
uation of pre-121 and 121-equipped vehicles in 
the field. The NHTSA believes that further 
notice and the opportunity for comment should 
precede any future changes of the stopping dis- 
tance requirements. 

Vehicle manufacturers conducted as much test- 
ing as possible, during the winter months, of the 



PART 571; S 121— PRE 74 



Effective: February 26, 1976 



proposed new loaded-vehicle stopping distances. 
Most concluded that the unloaded stopping dis- 
tance (258 feet versus 293 feet) would interfere 
with their efforts to "depower" braking suf- 
ficiently to reduce the possibility of adverse 
handling. The data on which the XHTSA based 
its proposal did not indicate that unloaded stop- 
ping distances would require relaxation in order 
to accomplish the desired depowering. Typically, 
unloaded performance is substantially superior 
to loaded performance and justifies shorter stop- 
ping distance requirements. 

The ATA pointed out that as one braking 
characteristic is changed its effect on other char- 
acteristics is unpredictable. In this case, it ap- 
pears that the recent testing demonstrates a 
sensitivity of unloaded to loaded stopping dis- 
tance that has not been fully appreciated until 
now. To implement the NHTSA intention to 
permit sufficient "depowering" for improved 
vehicle performance, the agency concludes that 
the required unloaded stopping distance should 
be made equal to the loaded vehicle distances, as 
recommended by Ford, PACCAR, Freightliner 
Corporation, and Midland-Ross. Other manufac- 
turers also stated that the shorter unloaded stop- 
ping distances could constitute a problem. The 
NHTSA considers it necessary, in light of this 
information, to increase the unloaded as well as 
loaded vehicle stopping distances. Table II is 
amended accordingly. 

In view of this modification, the proposed ex- 
clusion of certain specialized vehicles from the 
unloaded stop (proposed S5.3.1.3) is unnecessary 
and therefore not adopted. 

Wagner and some other commenters made the 
incorrect assumption that the XHTSA was con- 
cerned only with loaded-vehicle stopping per- 
formance of 121-equipped vehicles. "While the 
agency's proposed action only addressed loaded 
distances, the express purpose was to permit 
"depowering" for improved handling under all 
conditions. Wagner's view that the NHTSA 
intended the use of antilock for unloaded vehicle 
stops is incorrect. Actually, the XHTSA antici- 
pates that the depowering will have the effect of 
eliminating the need for antilock (or other me- 
chanical means for preventing uncontrolled 
wheel lockup) under all conditions in the case of 
manv vehicles. 



Besides the many recommendations to specify 
comparable unloaded stopping distance require- 
ments, commenters made vaiying suggestions for 
further change in stopping performance require- 
ments. Consolidated Freightways called for de- 
letion of the "antilock requirement" or, in the 
alternative, for cancellation of the standard. Its 
truck-manufacturing subsidiary (Freightliner 
Corporation) also called for prohibition of front 
axle brakes on three-axle truck-tractors. The 
ATA called for stopping distances that would 
guarantee deletion of front axle antilock. Mack 
Trucks, Inc., asked for deletion of the require- 
ment for "no lockup", performance on the front 
axle. White Truck Corporation asked for longer 
distances in some cases. International Harvester 
asked for a 330-foot stopping distance, or a more 
fundamental revision of the standard proposed 
by the company in December 1974. Ford re- 
quested that one wheel be permitted uncontrolled 
lockup during stopping tests, and suggested fur- 
ther rulemaking to "remove the need for antilock 
on all front axles." Bendix Corporation sug- 
gested suspension of the service brake stopping 
distances and "no lockup" requirements for 
trucks. 

The NHTSA judges that these requests are not 
directed at the "depowering" of overly effective 
brakes intended by tlie XHTSA proposal. For 
the most part, tiie recommendations appear to 
promote deletion of front axle antilock from cer- 
tain trucks that may not allow a controlled "no 
lockup" stop without the system. Consolidated 
Freightways, Bendix, and Roadway Express 
argued for deletion of antilock from the entire 
vehicle. At least in the case of these three re- 
quests, the concern is apparently based on the 
continued argument as to the reliability of anti- 
lock. In the proposal underlying this rulemak- 
ing, the XHTSA explained the basis for its 
determination that antilock is reliable, and since 
that time the agency has not developed or had 
reported information which modifies that view. 
An additional safety-related defect report, in- 
volving potential radio frequency interference 
with antilock function in one vehicle manufac- 
turer's products, has been reported, but no report 
of any accidents resulting from the defect has 
been made. The XHTSA maintains its convic- 
tion that antilock is sufficiently reliable to justify 



PART 571; S 121- 



-PRE 75 



Effective: February 26, 1976 



its continued installation in satisfaction of the 
standard's requirements for directional stability. 
Accordingly, the agency does not act on the rec- 
ommendations for deletion of the "no lockup" 
requirements or for distances calculated to elimi- 
nate the significance of the "no lockup" re- 
quirements. Consolidated's legal arguments on 
NHTSA rulemaking are being considered in the 
separate judicial review of Standard Xo. 121 and 
are not discussed in this notice for that reason. 

Freightliner suggested relaxation of emergency 
braking distances, and PACCAR recommended 
that the 35-foot stop from 20 mph be made a 
40-foot stop. The XHTSA did not propose these 
changes and does not believe them to be necessary 
for the "depowering" intended by the proposal. 
The 40-foot level would be no improvement over 
regulations existing prior to Standard No. 121. 
Furthermore, the agency gathers from the com- 
ments submitted that most elements of the in- 
dustry desire certainty in the standards to return 
stability to the truck manufacturing process. In 
the interests of this certainty, the agency does 
not intend to further consider the Freightliner 
and PACCAR requests. 

Along with the stopping distance modifications, 
the XHTSA proposed conforming changes in the 
dynamometer requirements. Brake fade and re- 
covery levels would be reduced somewhat by the 
proposal, the "hot stop" requirement would be 
deleted, and recovery requirements for the front 
axle of truck-tractors would be deleted. These 
proposals were intended to permit "depowering" 
of brakes to the 293-foot stopping-distance level. 

Rockwell International Corporation, a major 
supplier of foundation brakes and axle systems 
to the heavy vehicle industry, doubted that the 
dynamometer requirements would conform per- 
fectly to the new vehicle stopping distance re- 
quirements. Rockwell estimated that 10 to 12 
months might be required to accomplish adequate 
testing and reevaluation of brake sizes. The 
company suggested that all dynamometer re- 
quirements be suspended for an indefinite period. 

The NHTSA did not propose such a broad 
revision of the standard and would have to pro- 
pose such changes before they could be ini-^ 
plemented. Furthermore, a suspension of 
requirements without certainty as to their status 
at an unknown future date would reintroduce an 



element of uncertainty that Rockwell and many 
others cautioned against. For this reason, the 
modifications are implemented as proposed, and 
the NHTSA does not intend to act on Rockwell's 
recommendat ion. 

No objections were received on the general re- 
duction of brake fade and recovery performance 
and the air pressure values are amended as pro- 
posed. The ATA noted its support of the new 
values only if it permitted front axle brakes 
without antilock. Vehicle manufacturers gener- 
ally stated that limited testing did not permit 
unqualified endorsement of the new values. The 
California Department of Highway Patrol 
(CHP) suggested that a change of deceleration 
rate would be more realistic than the proposed 
change of air pressure actuation. In response to 
the CHP concern, it is noted that the increase in 
air pressure was chosen as the means to revise 
requirements so that the years of data developed 
in the past could be used for calculations of the 
new values. The NHTSA agrees with the CHP 
that a reduced deceleration rate would be more 
realistic if it were a feasible choice. 

The "hot stop" deletion was also supported, 
though most comments on the proposal stated 
that the whole section should be deleted and not 
simply the last sentence. The NHTSA purposely 
did not delete the whole section, so that the se- 
quence of testing would remain as in the past, to 
preserve the data on recovery that was developed 
following "hot stop" testing. Therefore the re- 
quired test level is deleted as proposed, but the 
(testing remains in the standard to maintain the 
same sequence as in the past. 

The deletion of recovery requirements on the 
front axle of truck-tractors was also supported, 
as it was discussed in the preamble. The pro- 
posed language incorrectly executed the 
NHTSA's intent as expressed in the preamble. 
With the necessary corrections, the proposals are 
made final as proposed. The CHP suggested an 
easing of "hot stop" requirements in place of 
deletion, but the agency does not consider it has 
a sufficient basis for the choice of new values, 
given the other reductions in dynamometer stop- 
ping distance values. 

The agency proposed reduction of retardation 
force requirements in the case of trailers to main- 
tain balance with the longer distances permitted 



PART 571; S 121— PRE 76 



Effective: February 26, 1976 



for trucks. The modifications were supported, 
although K-B Axle Company qualified its sup- 
port by noting that conforming linings might 
not be available immediately. The company 
suggested suspension of trailer retardation re- 
quii'ements. The XHTSA does not consider this 
suggestion meritorious, because it would leave no 
assurance of continued compatibility between the 
truck and trailer. 

Based on further testing, Rockwell supple- 
mented its original comments with a request for 
somewhat lower trailer retardation force levels 
than the 0.43 value proposed. The company 
justified a 0.40 value, based on variability ex- 
perienced in the new testing. A second manu- 
facturer of trailer axles (Eaton Corporation) 
supported a 0.40 value in meetings with the 
XHTSA. The new retardation values are there- 
fore implemented as proposed although at 
slightly lower values. In response to the CHP 
question concerning the need for numbering 
columns, these designations are necessary so that 
any future revision can be easily noted with 
precision. 

The XHTSA proposed reduction of parking 
brake performance levels for vehicles that oper- 
ate in combination, so that tlie vehicles, taken 
together, would produce approximated the same 
holding power as single-unit vehicles. Although 
petitioners PACCAR and Freightliner asked for 
reduction of grade-holding levels for all vehicles 
(and repeated these requests in their comments), 
the XHTSA rationale for the proposal was to 
accomplish the far more limited purpose of re- 
ducing the cost and weight of 121 -type parking 
brake systems on high-mileage tandem-axle ve- 
hicles that operate in combination. 

As proposed, however, the proposal applied to 
towed and towing vehicles with a single non- 
steerable axle as well as those equipped with 
tandem-axle assemblies. It is obvious that the 
desired cost and weight reduction intended in the 
proposal (typically removal of one set of spring 
brakes from one axle) cannot be achieved on a 
vehicle with only one non-steerable axle. At the 
same time, the proposal would permit less power- 
ful parking brakes on this vehicle category. The 
CHP pointed out that these single non-steerable- 
axle vehicles are connnonly operated in doubles 
operation, when parking brakes become more 



important in view of the total combination grade- 
holding ability. The XHTSA concludes that 
the proposal in the case of vehicles with single 
non-steerable axles will not accomplish the intent 
of the proposal and is therefore withdrawn. 

It also became apparent that the proposed re- 
duction in parking brake retardation force for 
tandem-axle trailers could not be justified. The 
proposed change from a 0.28 value to a 0.23 value 
was calculated on the basis of the share of a full 
load that the typical trailer should hold in com- 
bination with a truck-tractor to equal the per- 
formance of single-unit vehicles. X'o petitions 
were received requesting the modification, but 
possible weight and cost reductions were consid- 
ered possible. Fruehauf Corporation supported 
the proposal, while the Truck Trailer Manufac- 
turers Association stated that cost savings were 
unlikely from the proposed change. 

Unlike trucks and buses, trailers utilize the 
parking brake system as an emergency braking 
capability, in case of trailer "breakaway"' or 
other failure of the service brake system. Tliis 
parking brake system and emergency capability 
utilize the service brake friction elements and are 
thus directly dependent on the effectiveness of the 
service brakes. In view of the XHTSA decision 
to reduce trailer service brake effectiveness some- 
what more than proposed, the agency considers 
that the vehicle's emergency braking capability 
would be reduced too much by a commensurate 
reduction of parking brake requirements. There- 
fore the parking brake proposal for trailers is 
withdrawn. 

As for the tandem-axle truck-tractors for 
which the proposal was intended, it appears that 
the XHTSA estimate of a 0.17 retardation value 
was somewhat too high to accomplish the pro- 
posal's intent. PACCAR made several objections 
to any specification beyond that necessary to hold 
on a 15-percent grade. The company's testing 
showed that variability in materials and other 
factors required a 0.148 value in place of 0.17. 
Freightliner recommended a 0.16 value. AVliite 
Motor asked for a .15 value and Rockwell rec- 
ommended a .13 value. International Harvester 
supported the modification as proposed. XHTSA 
evaluation of submitted data indicates that a 
small decrease in the value from 0.17 to 0.14 is 
necessary to permit the intended deletion of 



PART 571; S 121— PRE 77 



Effective: February 26, 1976 



parking brake actuation meclianisms. Accord- 
ingly, the parking brake option of S5.6.1 is 
amended to reduce the retardation forces for 
tandem-axle truck-tractors. 

The CHP made extensive and detailed com- 
ments on the parking brake proposal which have 
been evaluated by the NHTSA. The CHP sub- 
mission assumed that only one non-steerable axle 
on buses and single-unit trucks would be equipped 
with parking brakes. This assumption appar- 
ently arose from a rearrangement of the wording 
of S5.6.1 that resulted in moving the phrase "on 
any axle other than a front steerable axle" in one 
subsection of the proposed modification. All 
other commenters understood the rearrangement 
and based their comments on the requirements 
as they have always existed for buses and single 
unit trucks. 

In response to a petition from the ATA, the 
agency proposed a 0.20-second limit on minimum 
brake actuation timing of towing vehicles. The 
ATA asserted that the compatibility of towed 
and towing vehicles would be improved by a 
limit on minimum actuation speeds as well as the 
minimum actuation timing already specified. 
Responses on the proposal by the manufacturers 
of brake components and of air-braked vehicles 
generally opposed the imposition of minimum 
actuation times. Of the manufacturers that 
commented, Rockwell supported the proposal 
without stating its rationale, and PACCAR and 
Freightliner stated qualified support for a mini- 
mum value, if the limit on maximum actuation 
times was raised or eliminated. The CHP sup- 
ported the proposal, although its engineering 
calculations were not expressed. 

From the comments submitted, the NHTSA 
concludes that a minimum actuation time is an 
insufficient means to assure compatibility, and 
that further study of adequate means is advis- 
able. Midland-Ross Corporation reminded the 
agency and industry that trailer response time is 
a separate but important portion of the problem. 
International Harvester argued that a limit on 
minimum actuation time might inhibit other 
modifications to improve compatibility. For 
these I'easons, the proposal to impose minimum 
actuation times is withdrawn. 

Manufacturers indicated that the 0.40 maxi- 
mum actuation time was discouraging the slower 



actuation time desired by the ATA. The agency 
concludes that the ATA request can in part be 
met by an increase in permissible actuation time 
in place of the requested limitation on minimum 
actuation times. Fgr this reason, the maximum 
permissible actuation time for trucks and buses 
is modified to 0.45 seconds from 0.40 seconds 
(S5.3.3). 

The delayed effective dates for certain cate- 
gories of specialized vehicles were also addressed 
by the proposal. In view of the uncertainty in- 
troduced by the proposal regarding the perform- 
ance levels, the agency considered it necessary 
to delay the effectiveness of the standard further 
for these vehicle classes. 

Reaction to this proposal in the case of fire- 
fighting vehicles (delay from March 1, 1976, to 
September 1, 1977) was not uniform. The Fire 
Apparatus Manufacturers Division of the Truck 
Body and Equipment Association supported the 
delay because custom vehicles utilize Rockwell 
antilock systems similar to those utilized on some 
buses. In the cases of buses, a major provision 
of the standard was suspended for a 1-year 
period to permit resolution of certain problems 
in the antilock system. Several small manufac- 
turers also supported the delay. Other manu- 
facturers indicated their readiness to meet the 
standard and asked that it not be delayed. Osh- 
kosh has been building 121 -equipped vehicles for 
some time and stated its reliance on the March 1, 
1976, date as the basis for preparations to com- 
mence production of the new systems in fire 
trucks by March 1976. American-LaFrance, a 
large manufacturer of fire fighting vehicles, also 
requested implementation of the standard as 
scheduled for fire figliting vehicles. 

In view of the statements of readiness by fire 
fighting vehicle manufacturers, the XHTSA has 
concluded that the standard should be imple- 
mented as soon as possible. The Rockwell anti- 
lock system on trucks has not evidenced reliability 
problems like those on buses that would justify 
a suspension of the requirements that underlie 
their use. However, the NHTSA proposal has 
justifiably permitted manufacturers to modify 
their plans and readiness, and the agency con- 
cludes that a short delay is necessary to allow 
preparations for the standard's implementation. 
Accordingly, the effective date for fire fighting 



PART 571; S 121— PRE 78 



EfNctlve: February 26, 1976 



vehicles is delayed from March 1, 1976, to June 1, 
1976. 

The Heavy Specialized Carriers Conference of 
the ATA, Fruehauf Corporation, the Truck 
Trailer Manufacturers Association, and Birming- 
ham Manufacturing Company all supported the 
proposed delay until September 1, 1977, of the 
standard's applicability to heavy hauler trailers. 
No objections were received on the proposed de- 
lay for auto transporters and vehicles with a 
gross axle weight rating (GAWR) for any axle 
of 24,000 pounds or more, or two or more front 
steerable axles with a GAWR of 16,000 pounds 
or more for each axle. "White Motor Corporation 
supported these delays as the minimum necessary, 
and supported a similar delay of the standard's 
full requirements for certain vehicles listed in 
S5.3.1.2. In view of the comments, the delays 
are made final as proposed. 

The CHP expressed concern that other large 
and specialized vehicle categories are permanently- 
excluded from the standard. The CHP antici- 
pates that, in the absence of Federal require- 
ments, a number of State regulations could be 
developed, some of which might be inadequate 
to ensure safety. The NHTSA is sympathetic 
to the concern, but at this time, considers it un- 
wise to initiate the suggested rulemaking. Large 
axle and brake suppliers like Rockwell are ab- 
sorbed in making calculations for the changes 
already proposed, and any further changes should 
await more deliberate and thorough review when 
more time is available. It is noted that Ameri- 
can-Coleman has filed a petition for the exclusion 
of more vehicles from the standard. Until these 
conflicting requests are resolved, the CHP cor- 
rectly notes that the States may continue to en- 
force their regulations against these vehicles. 

With regard to heavy vehicles, the CHP asked 
for a clarification of the limits on what consti- 
tutes the "rated cargo load" in the NHTSA 
definition of "unloaded vehicle weight." The 
NHTSA permits the rated cargo load and the 
gross vehicle weight rating to be determined by 
the manufacturer. If the CHP believes it has a 
better means of making that determination, its 
suggestion will be considered when received. 

Certain test procedures were questioned by 
commenters. Wagner asked for confirmation 



that unloaded truck-tractor tests do not include 
the use of an empty control trailer. Wagner is 
correct. Mack and Roadway Express suggested 
that unloaded vehicle tests should be run with 
the empty control trailer attached. This modi- 
fication has not been proposed and will not be 
acted on. With the increased unloaded vehicle 
stopping distance requirements, the NHTSA 
finds that the generally longer "bobtail" truck- 
tractor stopping distances should not interfere 
with adequate "depowering" of overly effective 
brakes. 

For testing, the NHTSA proposed that the 
control trailer braking capabilities remain at the 
same level as in the past, instead of being re- 
duced to conform to the proposed longer stopping 
distance requirements of S5.3.1. As Wagner 
recognized, this proposal was intended to permit 
the continued usefulness of past test data in 
making new calculations of necessary towing ve- 
hicle capabilities. Wagner, Bendix, and the 
ATA warned that the values will no longer be 
representative of equivalent production trailer 
stopping capabilities. Vehicle manufacturers 
supported the continued use of the existing con- 
trol trailer performance. The NHTSA concludes 
that, although the control trailer will be some- 
what less realistic than is normally desirable, this 
consideration is outweighed by the importance 
of maintaining the usefulness of the large amount 
of data already developed in the years of prepar- 
ing for implementation of the standard. There- 
fore the control trailer specification remains as it 
has in the past. 

The CHP requested that certain abbreviations 
in the standard be made uniform, and Wagner 
suggested that the standard be published in its 
entirety. The NHTSA anticipates these actions 
at the time of the next codification. 

The ATA questioned the statement that Euro- 
pean braking practice differs from the traditional 
practice in the United States of weak front 
brakes. In response, the NHTSA notes the re- 
cent Commission of European Commities di- 
rective for improved vehicle capability specified 
a higher retardation ratio for the front axle of 
commercial vehicles than on the rear axle. 

The Truck Equipment and Body Distributoi-s 
Association did not state its position on the pro- 



PART 571; S 121— PRE 79 



Effective: February 26, 1976 

posals made, but indicated that the requirements an immediate effective date is in the public 

of the standard as a whole present too great a interest. 

burden on the association's membership. This (ggc. 103, 119, Pub. L. 89-563, 80 Stat. 718 

issue is being litigated in the suit for review of (15 U.S.C. 1392, 1407); delegation of authority 

the standard and, for this reason, is not discussed at 49 CFR 1.50.) 

in this notice. 

T T I , £ ., >; 1 ^ Issued on February 26, 1976. 

In light or the loregomg, amendments are •' ' 

made in Standard No. 121, Air Brake Systems, 

49 CFE 571.121 James B. Gregory 

Effective date: February 26, 1976. Because Administrator 
these amendments effect the relaxation of re- 
quirements and create no additional burden upon 41 F.R. 8783 
any person it is found for good cause shown that March 1, 1976 



PAET 571; S 121— PRE 80 



Eff«c»lv«: July 19, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 



(Docket Nos. 75-7; 75-16; Notices 3 & 9) 



This notice republishes in their entirety Stand- 
ard No. 105-75, Hydraulic Brake Systems, and 
Standard \o. 121, Air Brake Systems, because 
the number and complexity of recent amendments 
to these standards may have created confusion 
for some interested persons. 

Standard No. 105-75 (49 CFR 571.105-75) was 
issued September 1972 (37 FR 17970, September 
2, 1972) and has been amended numerous times 
since issuance. Although an up-to-date and 
complete text of the standard appears each year 
in the republished Code of Federal Regulations, 
several complex amendments have been made to 
the standard in the past year that are not re- 
flected in the most recent up-to-date text. To 
assist interested persons who must be certain of 
the text's provisions, the agency herewith pub- 
lishes the standard in its entirety. Interested 
persons are advised that amendments of Standard 
No. 105-75 may occur in the future, although no 
proposals are outstanding at this time. 

In a related matter. General Motors Corpora- 
tion has brought to the agency's attention an 
inadvertent deletion of one sentence from one 
section of Standard No. 105-75. A statement was 
added to the text of S5.1.5.2(a) (2) to permit an 
interim increase in permissible control force for 
the fifth wet recovery stop (40 FR 24525, June 9, 
1975). Inadvertently, this sentence was deleted 
from S5.1.5.2(a) (2) in a subsequent rulemaking 
action (40 FR 42872, September 17, 1975), al- 
though the preamble to the notice made clear 
that "The new wording in no way modifies the 
meaning of S5.1.4(a) (2) and S5.1.5.2(a) (2)." 
To correct this omission, the sentence appears in 
this publication. It has been moved to S5.1.5.2 
(a)(1) because it concerns the maximum pedal 
force limit in that section, rather than the mini- 
mum pedal force limit in S5.1.5.2(a) (2) where 
it appeared in the past. 



Standard No. 121 (49 CFR 571.121) was is- 
sued in February 1971 (36 FR 3817, February 27, 
1971) and has also been amended numerous times 
since issuance. Several amendments have oc- 
curred since the most recent publication of the 
standard in its entirety. For the reasons cited 
with regard to Standard No. 105-75, the agency 
herewith publishes the standard in its entirety. 
Interested persons are advised that three pro- 
posals to amend the standard are outstanding 
(40 FR 45200, October 1, 1975) (40 FR 56920, 
December 5, 1975) (41 FR 20706, May 20, 1976) 
and that amendments to the text of the .standard 
may be made in the future. 

It has also been noted that a clarification could 
be made to the language of S3 of the standard 
that excludes until September 1, 1977, vehicles 
that combine with other vehicles to form auto 
transporters. The temporary exclusion was 
added to the standard in January 1975 (40 FR 
1246, January 7, 1975). To make the effect of 
that action more clear the language in the second 
sentence of the text "or to any vehicle which" is 
changed in this republication to read "or that." 
This modification of tlie language has no effect 
on the requirements of this standard and notice 
and opportunity to comment are therefore found 
to be unnecessary. 

In consideration of the foregoing. Standard 
No. 105-75 (49 CFR 571.105-75) and Standard 
No. 121 (49 CFR 571.121) are republished .... 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegations of authority 
at 49 CFR 1.50 and 49 CFR 501.8.) 

Issued on June 30, 1976. 

Robert L. Carter 
Associate Administrator 
Motor Vehicle Programs 

41 F.R. 29696 
July 19, 1976 



PART 571; S 121— PRE 81-82 



Effective: September 24, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-5; Notice 7) 



This notice amends Standard No. 121, Air 
Brake Systems, to extend until June 30, 1977, the 
period in which bulk ao^ricultural commodity 
trailers designed with a high ground clearance 
and other special features for use with farm 
tractors during harvest can meet emergency and 
parking brake requirements other than those 
specified in S5.6 and S5.8 of the standard. 

Standard No. 121 (49 CFR 571.121) permitted 
this specialized agricultural trailer category the 
option, until June 30, 1976, of meeting tlie park- 
ing brake requirements of the standard (actua- 
tion by an energy source unaffected by air loss 
in the service brake system) or the air-actuated 
"breakaway" system that complies with Bureau 
of Motor Carrier Safety requirements (49 CFR 
393.43). The National" Highway Traffic Safety 
Administration established the June 30, 1976, 
date (41 FR 8347, February 26, 1976) to permit 
completion of the bulk agricultural commodity 
trailers necessary for tlie 1976 harvest season. 

Titan Trailer Corporation petitioned for a 
year's extension of the option because tlie reasons 
cited by the agency for the option still exist, and 
the company plans to manufacture the specialized 
vehicles throughout the year. 

The agency does not wish to limit tlie manu- 
facture of these trailers to only one of the avail- 
able systems. In fact, the agency has an 
outstanding proposal to broaden the available 
means to meet the parking and emergency brake 
requirements for all trailers in a closely similar 
fashion to the bulk agricultural trailer option 
(40 FR 56920, December 5, 1975). Because of 
the comprehensive nature of that proposed re- 
vision, it will not be acted on in the immediate 
future. The NHTSA concluded that the option 
should be extended for a period to permit the 
continued manufacture of these trailers as they 



have been manufactured. The extension was 
proposed July 6, 1976 (41 FR 27740). 

Comments were received from Utility Trailer 
Manufacturing Company, Fruehauf Corporation, 
and Wesco Truck and Trailer Sales. All com- 
ments supported the proposal, and it is made 
final as proposed. 

In accordance with recently enunciated De- 
partment of Transportation policy encouraging 
adequate analysis of the consequences of regula- 
tory action (41 FR 16200, April 16, 1976), the 
agency herewith summarizes its evaluation of the 
economic and otiier consequences of the proposal 
on the public and private sectors, including pos- 
sible loss of safety benefits. Because the option 
simply permits continued manufacture of these 
trailers in the same fashion as they have been 
manufactured to date, and because the possibility 
for misuse of the mechanical parking brakes 
appears to be great in this case, the agency con- 
cludes that there would be no new economic or 
environmental costs imposed by the action, and 
that there would be no significant loss of safety 
benefit in this case. 

In consideration of tlie foregoing, the last sen- 
tence in paragraph So. 6 and So. 8 of Standard 
No. 121 (49 CFR 571.121) is amended by chang- 
ing the date "June 30, 1976" to "June 30, 1977." 

Effective date: September 24, 1976. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR 1.50.) 

Issued on September 22, 1976. 

John W. Snow 
Administrator 

41 F.R. 43153 
September 30, 1976 



PART 571; S 121— PRE 83-84 



EfFeclive: November 26, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 10) 



This notice amends Standard No. 121, Air 
Brake Systems, to extend from January 1, 1977, 
to September 1, 1977, the existing suspension of 
service brake stopping distance requirements as 
they apply to buses. Editorial changes are also 
made. 

Equipment used in transit and intercity buses 
to conform to the stopping distance requirements 
(S5.3.1) of Standard Xo. 121 (49 CFR 571.121) 
demonstrated a pattern of erratic behavior fol- 
lowing implementation of the standard for buses 
on March 1, 1975. For this reason, the agency 
suspended these stopping distance requirements 
(including the "no lockup" requirement) to pro- 
vide a period in which modified antilock hard- 
ware and newly introduced systems could be 
field-evaluated (41 FR 1598, January 6. 1976). 
Based on a petition for a longer suspension and 
on the agency's conclusion that the experience of 
a full year of antilock operation in all environ- 
mental conditions would be necessary to generate 
and analyze adequate data to make a sound deci- 
sion in time to permit orderly planning of bus 
production, a further suspension to September 1, 
1977, was proposed (41 FR 20706, May 20, 1976). 

Comments were received from vehicle manu- 
facturers and users, and from the two antilock 
system manufacturers that provide components 
for transit • and intercity bus antilock systems. 
The National Motor Vehicle Safety Advisory 
Council did not take a position on the proposal. 
The Vehicle Equipment Safety Commission did 
not comment on the proposal. Interested persons 
are advised that Docket Nos. 74-10 and 75-5 are 
related to the subject of air brake system re- 
quirements. 

The comments generally supported the pro- 
posed extension, and no commenter opposed the 



additional eight months for evaluation. AM 
General Corporation and Crown Coach requested 
that the suspension be extended to January 1, 
1978, but did not provide data that would sub- 
stantiate the need for additional time. Freight- 
liner Corporation, Rockwell International, and 
the American Public Transit Association 
(APTA) recommended that the stopping dis- 
tance requirements for buses be indefiniteh' sus- 
pended until justification for them is articulated, 
analysis of their "costs and other consequences" 
is set forth under Department of Transportation 
(DOT) policies (41 FR 16200, April 16, 1976), 
and extensive antilock system tests and evalua- 
tion have been completed. 

The requests by Freightliner. Rockwell, and 
APTA demonstrate a possible misunderstanding 
of the regulatory action under consideration, and 
the a' "^ncy therefore takes the opportunity to put 
it in perspective. The stopping distance require- 
ments of Standard No. 121 are in place for buses, 
and the only modification in the standard being 
considered is an extension of the temporary sus- 
pension of those requirements. Thus, if the 
agency takes no further action, the stopping dis- 
tance requirements resume on January 1, 1977. 
The agency's favorable action on the September 
1, 1977, date only means that the stopping dis- 
tance requirements resume September 1, 1977. 
No regulatory action to modify the requirements 
themselves is contemplated, and therefore no 
"impact evaluation" of these requirements would 
be appropriate under the DOT policies cited by 
APTA. 

Concern has been voiced that the agency set 
forth its rationale for specifying stopping dis- 
tance requirements (including "no lockup'" per- 
formance) in the case of buses. Several 



PART 571; S 121— PRE 85 



Effective: November 26, 1976 



commenters appear to be under the impression 
that Standard No. 121 is directed solel.y to the 
elimination of jackknifing by truck-trailer com- 
bination vehicles. In fact the standard applies 
to air-braked straight trucks and buses because 
of the evidence that these vehicles are also in- 
volved in accidents due to vehicle instability and 
inadequate braking capabilities. 

Jackknifing is only one severe result of the 
lateral instability caused by loss of traction due 
to locked wheels during braking. The same in- 
stability can also lead to sliding, "spin-out," and 
loss of steering capability in straight trucks and 
buses. The need for protection against such 
problems has been specifically addressed several 
times in earlier notices on the standard (e.g., 35 
FK 10368, June 25, 1970; 39 FR 44480, Decem- 
ber 24, 1974; 40 FR 24915, June 11, 1975; 41 FR 
8783, March 1, 1976). Rockwell asked that fur- 
ther analysis be provided that would be directed 
specifically at the accident experience of buses. 
The company suggested NHTSA analysis of the 
recent Bureau of Motor Carrier Safety Report 
on "1973/74 Accidents of Motor Carriers of Pas- 
sengers" and the data supporting the report. 
That report has been reviewed by the NHTSA, 
along with the individual bus accidents reports 
for 1975. 

The report itself (available in the NHTSA 
docket and from BMCS) emphasizes highway, 
driver, and time and place aspects of the acci- 
dents without detailing information that would 
indicate accident causation. The individual ac- 
cident reports, however, contain more complete 
information. Review and tabulation of informa- 
tion contained in the written descriptions of ac- 
cidents provides the following facts: 

1. In the year 1975, 750 bus accidents resulting 
in fatality, injury or a minimum of $2,000 in 
property damage were reported to BMCS. 

2. Of the total, 322 (43 percent) were described 
in a way that indicates that braking occurred 
prior to the accident. Sixty-eight (9.1 percent) 
of the accidents were explicitly described as in- 
volving skidding due to locked wheels during 
braking. The 68 skidding accidents I'esulted in 
6 fatalities, 296 injuries, and an average of $5,213 
property damage per accident. 

3. No antilock-equipped bus was involved in. 
any of these skidding accidents. 



The NHTSA does not claim that all of these 
accidents would have been prevented if the buses 
had been equipped with antilock systems. The 
accident descriptions are not detailed enough to 
estimate the effect of "no lockup" capability. But 
the evidence demonstrates that skidding accidents 
are common for buses, and it is reasonable to 
assume that a significant portion of those acci- 
dents could have been prevented or lessened in 
severity by no-lockup braking capability. 

Claims by transit bus operators that transit 
buses should be excluded from the "no lockup" 
requirement because of their low-speed urban 
operation are not substantiated by the BMCS 
data. Although most of the buses subject to 
BMCS regulation are of the intercity type, the 
accidents involving skidding are seldom high- 
speed accidents. For those cases in which vehicle 
speed prior to the accident was reported, it av- 
eraged only 36 mph. Furthermore, approxi- 
mately half of the skidding accidents occurred 
in residential or business areas. These conditions 
are typical of transit bus operation, and the 
NHTSA concludes that transit buses should be 
subject to minimum requirements for lateral sta- 
bility and service brake stopping capabilities. 

The issue at hand is whether the existing sus- 
pension of certain of the standard's requirements 
should be extended to September 1, 1977, to per- 
mit the accumulation of more test data on the 
suitability of modified and new antilock systems 
designed for buses. As noted earlier, erratic 
behavior of previous bus antilock designs foiTned 
the basis for the existing suspension. Recently, 
a manufacturer of cab-chassis for school buses 
has also reported a safety-related defect installa- 
tion in some school buses. 

On May 12, 1976, Rockwell submitted to the 
agency a proposed test program for its bus anti- 
lock system. The program called for 39 intercity 
and 85 transit buses to be equipped with the 
modified Rockwell system. Rockwell estimated 
an accumulation of more than 9.6 million axle 
miles of service by August 1, 1976. By August 
20, 1976, Rockwell had equipped 27 intercity and 
37 transit buses with revised components for 
testing. The number of test vehicles is less than 
originally planned, partly because of lack of co- 
operation by operators and State inspection of- 
ficials, and partly because of Rockwell's decision 



PART 571; S 121— PRE 86 



Effective: November 26, 1976 



to withhold further installation of test units un- 
til the agency makes final the 8-month extension. 
By August 20, 27 inoperative occurrences had 
been reported in 1.4 million axle miles of transit 
bus operation. Rockwell did not report results 
of intercity bus operations, but Motor Coach 
Industries (a manufacturer of intercity buses) 
reported 16 inoperative occurrences in approxi- 
mately 1.8 million axle miles of intercity service 
with the Rockwell system. 

In its May 12 letter, Rockwell also announced 
a parallel experimental testing program for a 
new antilock system design. To date, only one 
of these units has been placed in transit system 
service, and it has accumulated over 20,000 miles 
without difficulty. 

The AC Division of General Motors has also 
been testing an antilock system for buses. As of 
October 26, AC had installed its antilock system 
in 10 transit buses and 11 intercity buses. An 
additional 13 transit bus installations are planned 
in the near future. The transit buses range from 
zero to three months of service, with no problems 
encountered. Motor Coach Industries reported 
one inoperative occurrence in the six AC installa- 
tions they have made, with an accumulated mile- 
age of approximately 0.8 million axle miles. The 
other five AC-equipped intercity buses have ex- 
perienced no problems after about one month of 
service. 

AC Division indicated in its comments on the 
proposal that, barring any unforeseen difficulties, 
production AC antilock systems will be available 
for buses manufactured on and after January 1, 
1977. As of the date of this notice, AC Division 
has not notified the NHTSA of the development 
of any "unforeseen difficulties." Based on this 
information and analysis of the reliability data 
furnished to date, the agency has decided to 
amend Standard No. 121 as proposed to extend 
the suspension of bus stopping distance require- 
ments to September 1, 1977. The preliminary 
data indicate that a reliable antilock system will 
be available in time for reinstatement of the re- 
quirements, and a further delay is not contem- 
plated. 

An issue related to this decision on bus stop- 
ping distance requirements was raised in the 
comments to the proposal. Rohr Industries and 



International Harvester requested that the sus- 
pension of stopping distance (and "no lockup") 
requirements be made "retroactive" to buses 
manufactured since the effective date of Stand- 
ard No. 121 but prior to the January 6, 1976, 
commencement of the suspension. 

The statutory and regulatory scheme under 
which the standard was promulgated do not pro- 
vide for such "retroactive" action. Section 108 
(a)(1)(A) specifies that a vehicle shall comply 
with standards in effect on the date of its manu- 
facture. Part 571 of NHTSA regulations also 
state: ". . . each standard set forth in [Part 571] 
applies according to its terms to all motor vehicle 
or items of motor vehicle equipment the manu- 
facture of which is completed on or after the 
effective date of the standard" (49 CFR 571.7). 
In this case, antilock systems have been discon- 
nected because of safety-related defects in their 
operation. Under § 154 of the xVct, the vehicle 
manufacturer Mnust provide an adequate repair 
of safety-related defects, unless replacement of 
the vehicle, or refund of the purchase price, is 
undertaken. "Adequate repair" is defined in 
§ 159(4) not to include "any repair which results 
in substantially impaired operation of a motor 
vehicle or item or replacement." The permanent 
disconnection of an antilock system would be 
considered by the NHTSA to constitute substan- 
tial impairment of the motor vehicle. Of course, 
the vehicle owner is entitled to decline an offer 
of repair by the manufacturer. 

In a matter unrelated to tiie proposal, the 
agency takes the opportunity to make several 
editorial changes to the text of Standard No. 121. 
A correction in So. 1.7 ("statically" in place of 
"statistically"), conformance of the auto-trans- 
porter effective date in S5.3 to the correct date 
in S3 (September 1, 1977), and deletion of an 
obsolete reference to S5.3.1.3 in S5.3.1 are all 
effectuated. Additionally, options that terminated 
in June and September 1976 are deleted to sim- 
plify the standard's text. 

In accordance with Department of Transporta- 
tion policy encouraging adequate analysis of the 
cost and other consequences of regulatory actions 
(41 FR 16200, April 16, 1976), the NHTSA has 
evaluated the economic and other consequences 
of this amendment on the public and private 



PART 571; S 121— PRE 87 



Effective: November 26, 1976 

sectors, including possible loss of safety benefits. Effective date: November 26, 1976. 

The agency estimates that there will be a cost to (g^^^ ^q^,, 119, Pub. L. 89-563, 80 Stat. 718 

society due to the delay, because of the decreased (^^ ^.S.C. 1392, 1407) ; delegation of authority 

stability of buses produced without "no lockup" ^^ ^g CFR l-oO ) 

capability. However, the potential for accidents 

due to possible malfunction of the new antilock Issued on November 19, 1976. 

components exists in the absence of the longer 

suspension. Also, there are costs associated with 

the increased maintenance that could result from John W. Snow 

reintroduction of antilock systems earlier than Administrator 

September 1, 1977. 

In consideration of the foregoing. Standard 41 F.R. 52055 

No. 121 (49 CFR 571.121) is amended November 26, 1976 



PART 571; S 121— PRE 



Effective: June 13, 1977 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; NoHce 12) 



In response to two petitions for reconsideration 
of earlier rulemaking and to related requests, the 
NHTSA has extended for four months the exist- 
ing suspension of the bus service brake stopping 
distance requirements contained in Standard No. 
121, Air Brake Systems, along with an addi- 
tional 3-month extension for school buses. A 
manufacturer of intercity buses and a manufac- 
turer of school bus chassis petitioned to extend 
the suspension, which was scheduled to end Sep- 
tember 1, 1977. The delay in reaching a decision 
on the petitions has made a short extension de- 
sirable. 

Effective date : June 13, 1977. 
For further information contact: 

George Reagle 

Office of the Administrator 

National Highway Traffic Safety 

Administration 
400 Seventh Street, S.W. 
Washington, D.C. 20590 
(202 426-1836) 

BACKGROUND 

Standard No. 121 (49 CFR 571.121) regulates 
the braking system performance of air-braked 
trucks, buses, and trailers. The standard has 
been in effect for trailers since January 1, 1975, 
and for trucks and buses since March 1, 1975. 
Following implementation of the requirements 
for buses, a pattern of erratic behavior developed 
in the performance of the antilock system used 
by manufacturers of transit and intercity buses 
to satisfy the "no lockup" requirements of tlie 
standard (S5.3.1). At an October 1975 public 
meeting the bus operators and manufacturers in- 
volved reviewed their experiences with imple- 
mentation of the standard and expressed their 



views on potential safety hazards of antilock 
malfunction. Based on these and other reports, 
the NHTSA propoeed a suspension of the ser\dce 
brake stopping distance requirements (including 
the "no lockup" requirement) to provide a period 
in which modified antilock hardware and newly 
introduced systems could be field-evaluated (40 
FR 52856; November 13. 1975). The proposed 
suspension of 1 year until January 1, 1977, was 
made final January 6, 1976 (41 FR 1598; Jan- 
uary 9, 1976). Several vehicle manufacturers 
and user groups argued that the suspension 
should be for a longer period and the suspension 
was subsequently extended from January 1, 
1977, to September 1, 1977 (41 FR 52055;' No- 
vember 26, 1976). 

PETITIONS AND REQUESTS FOR DELAY 

Motor Coach Industries (MCI) and its parent 
company Greyhound Corporation have asked 
that the termination of the suspension for service 
brake requirements be delayed until January 1, 
1979, in the case of intercity buses. The Ameri- 
can Public Transit Association (APTA) also 
petitioned for the same delay in the case of both 
intercity and transit buses. The Chicago Transit 
Authority (CTA) reconunended complete exclu- 
sion of transit buses from the standard, although 
the arguments in their letter only address the 
"no lockup" requirement, and the CTA may have 
meant to request exclusion from this requirement 
only. 

Transit and intercity buses use a distinctive 
axle configuration, and only one supplier of anti- 
lock components for the axle exists. The sup- 
plier, AC Division of General Motors, has 
indicated its readiness to supply antilock com- 
ponents to transit and intercity bus manufactur- 



PART 571; S 121— PRE 89 



Effective: June 13, 1977 



ers (and those school bus manufacturers that 
utilize the same distinctive axle). 

International Harvester (IH) petitioned for 
reconsideration of the September 1977 termina- 
tion date for stopping distance requirements in 
the case of air-braked scliool buses, arguing that 
reliability testing of new sensor and mounting 
components would require continuation of the 
suspension until mid-April 1978. IH had re- 
ported a safety-related defect in its school bus 
antilock system in July 1976 due to vibration- 
induced "false cycling" problems associated with 
the school bus duty cycle. While IH and its 
antilock supplier are not experiencing reliability 
problems with the new antilock component used 
on school bus chassis, the company wishes to 
accumulate at least 6 months of field evaluation 
before going into production. IH and Kelsey- 
Hayes (its antilock supplier) met with the 
NHTSA engineering staff on February 17, 1977, 
to provide information on the field evaluation. 
That meeting was followed by additional meet- 
ings and a detailed letter request to Kelsey- 
Hayes for further durability testing data. 

This notice also responds to a recommendation 
on the bus suspension from the Truck and Bus 
Safety Subcommittees of the National Motor 
Vehicle Safety Advisory Council and the Na- 
tional Highway Safety xVdvisory Committee. 
These subcommittees were established by the 
Secretary of Transportation to provide recom- 
mendations on truck and bus safety. At the 
request of former NHTSA Administrator John 
Snow, the subcommittees convened in March 
1977 to address the issue of Standard No. 121's 
implementation. From that meeting, the sub- 
committees recommended, among other things, 
continuation of the suspension of service brake 
requirements for buses until January 1, 1979. 
The American Trucking Association (ATA) has 
since petitioned the NHTSA to adopt this and 
related recommendations of the subcommittees. 

EVALUATION OF THE PETITIONS 

While most of the petitions, requests, and rec- 
ommendations were not accompanied by support- 
ing information, the MCI and IH petitions 
included data on reliability testing to support 
their requests. Data on the AC Division system 
used on intercity, transit, and some school buses 



was evaluated separately from the data on the 
Kelsey-Hayes system used by IH on its school 
bus chassis. 

Intercity and Tramit Buses. When the bus 
service brake stopping distance suspension was 
proposed in November 1975, AC Division indi- 
cated that it would enter the intercity and transit 
bus antilock market, and MCI agreed to have 
one of its intercity buses equipped with AC 
equipment. MCI equipped a second bus with 
AC equipment on an experimental basis and sub- 
sequently installed four more systems on a pro- 
duction line basis in 1976. 

The 1-year suspension was made final in Jan- 
uary 1976. In May 1976 the agency proposed 
continuation of the suspension to September 1977 
"to have the experience of a full year of antilock 
operation in all environmental conditions, par- 
ticularly in the winter season" and to permit 
reaching "a sound decision in time to pennit 
orderly planning of bus production." 

In making final the 8-month extension in No- 
vember 1976 the agency noted AC Division's test 
experience with bus antilock systems (including 
data on MCI buses) and AC's position that it 
expected to have antilock ready as production 
hardware by January 1, 1977. The NHTSA 
therefore notified the public that "The prelimi- 
nary data indicate that a reliable antilock system 
will be available in time for reinstatement of the 
requirements and a further delay is not con- 
templated" (41 FR 52057; November 26, 1976). 
In a February 1977 meeting with the NHTSA, 
AC Division indicated that it has production 
hardware ready on a 4-month leadtime basis, and 
that General Motors is prepared to equip its own 
production of intercity, transit, and school buses 
with its product starting September 1, 1977. 

AC Division field-evaluated its system on 
GMC buses (both intercity and transit), on 
Flxible transit buses, on one Prevost intercity 
bus, and on MCI intercity buses. AC reported 
to the NHTSA on 34 installations, of which six 
were MCI buses. Data were reported on the 
MCI buses both for an early generation of com- 
ponents and for a later set. Second generation 
computers were supplied so that common com- 
puters with a new diagnostic feature could be 
used on trucks and buses. Prototypes of second 



PART 571; S 121— PRE 90 



EfFective: June 13, 1977 



generation sensors were provided to account for 
bus brake temperatures that are higher than 
those of trucks, and to prevent water intrusion 
in the new design. 

In analyzing re^Dorted malfunctions on the 
MCI buses, the agency eliminated three "burned 
out" computer failures that occurred while the 
bus was in the shop and were caused by a me- 
chanic's negligence that permitted a "severe load 
dump" to the electrical system. A malfunction 
caused by improper bearing adjustment was also 
eliminated. As of Api'il 25, 1977, 5 malfunctions 
had occurred during 2.8 million axle miles of 
travel (187,000 vehicle miles per failure). The 
malfunctions were "fail safe" and all occurred 
before the corrections discussed above. Mileage 
since the corrections produced no malfunctions. 

The AC Division bus antilock system is essen- 
tially the same as AC truck systems that have 
proved reliable in service since their introduction 
in early 1975. ^Vliile the agency does not dispute 
MCI's view of what level of testing it considers 
appropriate, the NHTSA has confirmation by 
General Motors, as a manufacturer of both inter- 
city and transit buses, that they are confident of 
the AC Division system and are prepared to 
place it on their vehicles. 

At the same time, the second generation sensor 
is entering production at this time for installa- 
tion on trucks, and production units will be 
available for further evaluation in the more de- 
manding bus application. In view of this oppor- 
tunity for evaluation of redesigned sensors built 
on production tooling, and in view of the agency's 
delay in responding to the petitions for recon- 
sideration, it is concluded that a short continua- 
tion of the suspension until January 1, 1978, is 
justified. Accordingly, on reconsideration of the 
September 1, 1977, termination date established 
last November, the NHTSA hereby extends the 
suspension to January 1, 1978, for transit and 
intercity buses. 

The CTA asked for total exclusion of transit 
buses from tlie standard but addressed only the 
issue of antilock system reliability. APTA pe- 
titioned for continuation of the suspension for 
both transit and intercity buses, although the 
association's arguments addressed only transit 
buses. APTA reviewed experience with the 



Rockwell system that had developed problems in 
early 121-equipped buses, cited the subcommit- 
tees' recommendation for further delay, and 
recommended the initiation of a 6-month 200- 
vehicle fleet test prior to implementing the serv- 
ice brake stopping distance requirements. 

The NHTSA has analyzed the two petitions 
and does not believe that they provide additional 
information that would justify a delay beyond 
January 1, 1978, for these buses. The CTA did 
not provide data that would substantiate its as- 
sertions that radio frequency interference (RFI) 
is a problem, or that transit buses do not require 
"no lockup" performance. The NHTSA believes 
the references to RFI refer to the past system 
used on buses. AC Division has detailed the 
precautions it has taken against RFI, and it has 
had field experience with its system on trucks for 
more than 2 years. The safety need for "no 
lockup" performance on transit buses was dis- 
cussed by the NHTSA in the November 1976 
notice cited earlief, and the agency maintains its 
view of the desirability of this safety feature. 

The majority of APTA's comment addressed 
the Rockwell sj'stem that is no longer in use. 
The only comment about the AC Division system 
pointed out the introduction of the second gen- 
eration sensor in June 1977 and concluded that a 
200-bus fleet test of the antilock components 
would be desirable. The NHTSA has explained 
above why it considers a 4-month delay adequate 
to be assured of reliability of this component. 
As to the size of the test fleet, it is the agency's 
view that the APTA membership could have 
tested 200 units on its transit bus fleets during 
the past 18 montlis if it had cared to. The 
agency is not aware of APTA objections to the 
size o2 the AC Division test effort at the time it 
was constituted as a 34-bus fleet. 

School hiises. In the case of air-braked school 
buses, a comparable situation has arisen to that 
of intercity and transit buses. Second generation 
componentry for IH buses has been introduced 
by Kelsey-Hayes, no reliability problems have 
been encountered, and the subcommittees also 
recommended continuation of the suspension. 
While the same considerations argue for a 4- 
month delay, the agency does not have as many 
miles of field data on the newly designed sensor 



PART 571; S 121— PRE 91 



Effective: June 13, 1977 



and mounting bracket upon which to make a 
judgment of system reliability as it did in the 
case of the AC Division system and its new 
sensor. In addition, most school buses receive 
little or no use during the summer months. For 
this reason the NHTSA concludes that the full 
period of delay requested by IH in its petition 
for reconsideration should be allowed. In this 
period, approximately 100 new sensor installa- 
tions will be monitored to provide full assurance 
of system reliability. Accordingly, 3 additional 
months of suspension have been provided in the 
case of school buses only. 

TRUCK AND BUS SAFETY 
SUBCOMMITTEES 

The NHTSA Administrator invited the sub- 
committee's Chairman to hear a presentation of 
NHTSA findings on the issue of continued sus- 
pension for buses. That invitation was expanded 
to include those members of the subcommittees 
that wished to accompany the Chairman to the 
April 22, 1977, briefing. Although not planned 
as a meeting of the subcommittees, a summary 
of the meeting has been prepared for submission 
to the public docket. 

The subcommittees heard the agency's views 
and offered their own. The agency weighed the 
points made by the subcommittees in support of 
a delay until January 1, 1979, but concluded that 
adequate field-testing time would be available to 
make preparations for meeting the full require- 
ments of Standard No. 121 by January 1, 1978, 
in the case of transit and intercity buses, and by 
April 1, 1978, in the case of school buses. The 
American Trucking Associations had petitioned 
the NHTSA to follow the subcommittees' recom- 
mendation of a January 1, 1979, effective date 
for buses and other enumerated vehicles. To the 
degree that this decision does not grant the 
American Trucking Associations' petition rela- 
tive to buses, it is denied for the reasons set forth 
above. Other items in the ATA petition will be 
treated in subsequent notices. 

At the meeting the agency expressed its view 
that it is incumbent on a manufacturer asking 
for more test time to explain why its test pro- 
grams had not been enlarged to proportions that 
would give adequate assurance of reliability by 



the scheduled termination date. Opportunities 
to expand the test program in this case existed 
in November 1976 when the agency stated it con- 
templated no further delay and again in January 
1977 when Rockwell withdrew as a supplier of 
antilock systems. The agency urged expansion 
of test programs when requests for further delay 
were received. Contacted about the size of its 
test fleet, MCI indicated that the test fleet was 
kept small in the first instance so that it could be 
carefully moniored to avoid accidents. Only 
after some confidence in the safety of the new 
components is accumulated will MCI expand its 
programs to a larger number of buses. 

The agency knows that it cannot and should 
not design a manufacturer's test program. At 
the same time, the agency cannot be prevented 
from carrying out its safety mission simply by 
the decision of a manufacturer not to undertake 
design and testing of safety systems proposed by 
the agency. It is obvious from the legislative 
history of the National Traffic and Motor Vehicle 
Safety Act that Congress intended the manufac- 
turers to be responsive to the agency's proposals 
for upgrading safety systems. 

While the agency has not adopted completely 
the recommendation of the subcommittees in the 
case of buses, their recommendations have formed 
the basis of several significant actions by the 
Department of Transportation. Noteworthy in 
this regard is the decision by the Federal High- 
way Administration's Bureau of Motor Carrier 
Safety (BMCS) to commence "courtesy inspec- 
tions" of 121 -equipped vehicles later this year. 
In the near term, these courtesy inspections are 
for informational, educational, and training pur- 
poses, and are intended to form the basis for 
future BMCS compliance inspections. 

In consideration of the foregoing, the phrase 
"Except for a bus manufactured before Septem- 
ber 1, 1977" in S5.3.1 of Standard No. 121 (49 
CFR 571.121) is amended to read "Except for a 
school bus manufactured before April 1, 1978, or 
any other type of bus manufactured before 
January- 1, 1978." 

The economic and inflationary impacts of this 
rulemaking have been evaluated in accordance 
with Office of Management and Budget Circular 



PART 571 ; S 121- 



-PRE 92 



Effective: June 13, 1977 

A-107, and an Economic Impact Statement is (Sec. 103, 119, Pub. L. 89-.563, 80 Stat. 718 

not required. (15 U.S.C. 1392, 1407) ; delegation of authority 

Because the amendment delays requirements at 49 CFR 1.50.) 

that would otherwise become effective and does Issued on June 7, 1977. 

not create additional obligations for any person, 

the agency finds that the amendment may become 

effective immediately. J^^n Claybrook 

n„ a: ■ 1 J I • • ii Administrator 

Ihe program oracial and lawyer prmcipally 

responsible for this rulemaking are Duane Perrin 42 F.R. 30188 

and Tad Herlihy, respectively. June 13, 1977 



PART 571; S 121— PRE 93-94 



I 

I 



EffecNve: August 22, 1977 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 15) 



This amendment adds a small number of ve- 
hicles to the category of oversize and specialized 
vehicles that are permanently excluded from the 
applicability of Standard No. 121, Aif Brake 
Systems, extends the existing temporary exclu- 
sion of heavy hauler trailers and auto trans- 
porters until January 1, 1979, and eliminates the 
"no lockup" requirement in the case of trailers 
designed exclusively for liarvesting lumber or 
pulpwood, and in the case of inboard wheels on 
trailers with more than four wheels on an axle 
system. The amendment responds to manufac- 
turer petitions for exclusion from some or all of 
the requirements of the standard because of the 
vehicles' distinctive configurations and functions. 

Effective date: August 22, 1977. 

Addresses: Petitions for reconsiderations 
should refer to the docket number and be sub- 
mitted to: Room 5108, Nassif Building, 400 
Seventh Street, S.W., Washington, D.C. 20590. 

For further information contact: 

Duane Perrin 

Office of Crash Avoidance 

National Highway Traffic Safety 

Administration 
Washington, D.C. '20590 
(202-426-21.53) 

Supplementary Information : Standard No. 
121 (49 CFR 571.121) regulates the braking sys- 
tem performance of air-braked trucks, buses, and 
trailers, and has been in eftect for trailers since 
Januai'y 1, 1975, and for truclcs and buses since 
March 1, 1975. Certain vehicles were excluded 
iron\ the standard's applicability because their 
functions or construction dictate oversize or dis- 



tinctive operational characteristics that result in 
restricted highway operation (e.g., low speed, 
permit requirements, daytime operation), which 
limits hazards and the possibility of accidents. 
Also their distinctive configurations and low pro- 
duction volumes increase compliance costs. 

Because of unavailability of components and 
other constraints, certain other vehicle categories 
were excluded from all or some of the stand- 
ard's requirements for a temporary period. The 
temporary exclusions that remain in effect are 
scheduled to end on September 1, 1977. 

Several vehicle manufacturers and trade asso- 
ciations petitioned for extension of some of the 
temporary exclusions, or conversion of them into 
permanent exclusions. The Truck and Bus 
Safety Subcommittees of the National Motor Ve- 
liicle Safety Advisory Council and National 
Highway Safety Advisory Committee recom- 
mended to the Secretary of Transportation that 
particular vehicle types be granted full or partial 
exclusions from the standard. 

Based on consideration of the petitions and 
on the recommendations of the Truck and Bus 
Safety Subcommittees, the NHTSA proposed 
several new permanent exclusions from the stand- 
ard. The 108-inch-width exclusion was proposed 
for expansion to include vehicles with a width 
of more tiian 102 inches. In all states other than 
Hawaii, vehicles of this width are allowed on 
the highway only in permit operation. The 
agency finds that these vehicles are operated 
with the same level of care as vehicles of 108 
inches in overall width. No adverse comment 
was received on the proposal and it is accord- 
ingly made final. 



PART 571; S 121— PRE 95 



Effective: August 22, 1977 



The agency proposed permanent exclusion of 
vehicles whose gi-oss vehicle weight rating 
(G^^VK) exceeds 120,000 pounds, under the 
assumption that such vehicles always operate 
under restrictions of state motor vehicle admin- 
istrations. Comments were solicited on whether 
such v^ehicles exist that are not already excluded 
from the standard under another category, and 
whether such vehicles ever operate in unrestricted 
highway use. Fruehauf, Rogers Brothers, and 
Talbert Trailers pointed out that Michigan 
allows unrestricted highway operation of certain 
trailers in excess of 120,000 lbs. GVWE. These 
trailers may be flatbeds, tankers, or dump bodies 
with 8 or more axles and are currently being 
built to conform to the standard. Low bed heavy 
hauler trailers, on the other hand, must have 
their axles aft of the load, and do not have room 
for as many as eight axles without exceeding 
the state length limit requirements, and hence 
are still subject to restricted operation. It is 
apparent that the exclusion should be narrowed 
so that its language reaches only those vehicles 
originally intended for exclusion. It appears 
that only low bed "heavy hauler" trailers in this 
weight range fall under state operating restric- 
tions. As made final, therefore, the exclusion is 
narrowed to cover only a trailer that has a 
GVIVR of more than 120,000 pounds and a body 
that conforms to the height limitation for heavy 
hauler trailers of 40 inches. Fruehauf suggested 
a 44-inch deck height criterion, but offered no 
supporting information, and the NHTSA sees 
no reason to change from the 40 inches presently 
specified for heavy hauler trailers. 

The third proposed permanent exclusion was 
for "load divider" dollies that are designed ex- 
clusively for use with the larger trailers that are 
already excluded from all the requirements of 
the standard. This addition was supported, but 
the Truck Trailer Manufacturers Association 
(TTMA) and others requested a correction in 
the description of the vehicle. The agency re- 
ferred to the "fifth wheel plate" of the dolly 
which improperly described the connecting ot- 
mating devices employed. The proposal is made 
final, with an appropriately broader statement of 
vehicle description. 



Several commenters argued for additional per- 
manent exclusions from the standard. Schwartz 
Manufacturing Company asserted that the "heavy 
iiauler" trailers that are currently excluded from 
the standard for a limited period should all be 
permanently excluded because of their off-iiigh- 
way use and their typical ownership by a small 
company with limited maintenance resources. 
The agency has proposed and is making final an 
extension of the existing temporary exclusion 
while it develops more data on the difficulty en- 
countered by manufacturers in constructing these 
vehicles to comply with the standartl. Informa- 
tion requests have been issued by the agency and 
replies have been received which are presently 
undergoing analysis. Until analysis is com- 
pleted, it would be premature to act on the 
Schwartz request, and it is therefore declined. 

Master Truck, the City of San Diego, and the 
Lake Disposal Corporation supported the Truck 
and Bus Safety Subcommittees' suggestion to 
exclude refuse trucks from Standard No. 121 
entirely, or at least from the "no lockup" pro- 
vision. The commenters pointed out that the 
duty cycle of these vehicles differs from that 
for highway tractor-trailer combinations and 
that much of the travel is at low speeds Iwtween 
pick-ups. The City of San Diego pointed out 
that it must purchase from the low bidder, which 
can result in having to service several of the com- 
mercially available antilock systems, thereby 
compounding maintenance problems. The agency 
does not dispute these points, but also does not 
view them as peculiar to the brake systems of 
these vehicles. Refuse collection and haiding 
presumably do put distinctive strains on a ve- 
hicle, and the problem of low-bid contracting 
does occur in municipal fleet maintenance. It 
is assumed that such problems with braking and 
other vehicle systems occurred prior to imple- 
mentation of Standard \o. 121 and that adaptive 
steps were taken to compensate for them. It is 
conceivable, in fact, that some of tlie adaptations 
(such as the use of longer wearing but less effec- 
tive brake linings) may have reduced somewhat 
the braking capal)ility of some I'efuse haulers in 
I'clation to vehicles of comparable size that serve 
other functions. It is the agency's considered 



PART 571; S 121— PRE 96 



Effective: August 22, 1977 



judjrment that the duty cycle of a particular 
vehicle type should not be fully determinative 
of its brakinj^ capability or general safety char- 
acteristics. For this reason, the aj^ency declines 
to act on requests for exclusion of these vehicles 
but will continue to <rive consideration to this 
and other proposed adjustments in tlie standard's 
applicability. 

Zieman Manufacturin<r Company asked that 
trailers with a GVWR of 10,000 pounds or less 
with air-over-hydraulic brakes be excluded from 
the standard's applicaliility. Such an exclusion 
was proposed in June 197.") (40 FR 2491.5, June 
11, 1975) in response to the petition of Altec 
Industries. On the basis of comments received, 
particularly tliose of the California Hifrhway 
Patrol, it was decided not to provide such an 
exclusion because of the potential for abuse of 
the category. The Zioiian re(iuest is therefore 
not adopted. 

No comment was received from any mobile 
crane manufacturer on the wisdom of continuing 
tiie present limits for these vehicles: exclusion 
of larger categories only, unless top speed is re- 
stricted to 4.5 mpli. In the absence of conunent. 
the agency has decided to leave the present ex- 
clusions affecting mobile cranes imchanged, ex- 
cept for the over 102-inch width exclusion 
previously discussed. 

It is noted that the existing pennaneiit exclu- 
sion of non-cargo-carrying trailers was iiuuhei't- 
ently restated in the proposal in exactly the 
opposite form fi"om that intended. Tlie eiror is 
corrected in this amendment. 

As a general matter, the continuation of tem- 
porary exclusions for lieavy liauler trailers and 
auto transporters was supported. Little infor- 
mation was provided in tlie comments on tlie 
readiness of manufacturers to implciiicnt tlie 
standard by January 1, 1979. Inforination re- 
quests have lieen sent to tlie afiVrtcd nianiit'iic- 
turers to develoj) additional data. Frciglitliiicr 
Corporation, as the luanufnctiiror of iiicoiuplote 
truck ti-actors for auto transporter coiiibiiiatious. 
argued for the indefinite exclusion of tlicsc cniu- 
binations from the standard. 



Freightliner's first argimient was that the high 
center-of-gravity characteristics of the towing 
vehicle (car carired over the cab) and the unique 
load transfer characteristics of the articulation 
point on some auto transporters can produce 
effects which combine to offset the advantages 
of imposition of the standard on these vehicles. 
The agency understands that these factors can 
make compliance for auto transporters more diffi- 
cult, and has acknowledged this fact by pro- 
posing an effective date for auto transporters 
that is four years after the initial effective date 
for other highway vehicles. However, tlie 
agency is also aware that auto transporters can 
be (and have been) built to comply fully with 
the present requirements of the standard. If 
Freightliner or any other interested party has 
data to show that the present requirements are 
insufficient to ensure a safe braking system for 
auto transporters, the agency solicits their sug- 
gestions for improvements. 

As a practical matter, the agency has stated 
(May 5, 1975, NHTSA letter to E. Hammond, 
Trailmobile Tech. Center) that it will use the 
chassis manufacturer's load limitations, both 
weight and center-of-gravity. for purposes of de- 
termining compliance. Thus Freightliner's "en- 
velope" of specifications in its incomplete vehicle 
flocument would be the outside limit for loading 
the completed tractor for compliance test pur- 
poses. The only limitation on this method would 
be an "envelope" of specifications so conservative 
that the braking characteristics of the vehicle 
as completed would constitute a safety-related 
defect. 

The second point raised by Freightliner is that 
the testing pi-ocedures in the standard may need 
to be modified before tractors and trailers of the 
auto transporter combination can be tested sep- 
arately. During the period of continued delay, 
the NHTSA intends to call a puldic meeting to 
discuss this problem with the affected chassis- 
cab manufacturers and the auto transporter in- 
dustry. Freightliner's suggestion for indefinite 
delay appears unnecessary and. accordingly, is 
declined. 



PART 571; S 121— PRE 97 



EfFecHve: August 22, 1977 



Freightliner's third argument was that, assum- 
ing that incompatibility between the tractor and 
trailer portions of an auto transporter is great, 
the agency should not require their compliance 
with the standard until all incompatibility is re- 
moved from all air-braked vehicle combinations 
subject to the standard. Actually, the compati- 
bility problems between tractor and trailer are 
probably less in the case of auto transporters 
than other combinations because there is more 
pairing of tractors and trailers in this industry 
than in the case of dry freight vans. The 
NHTSA tests mentioned by Freightliner will be 
completed prior to the January 1. 1979, effective 
date for auto transporters. 

PACCAR, Inc., and Mack Trucks, Inc., both 
commented favorably on the American Trucking 
Association's request to continue the exclusion 
of vehicles equipped with an axle with a gross 
axle weight rating (GAWR) of 24,000 pounds 
or more. The agency did not propose continua- 
tion because no vehicle or axle manufacturer had 
petitioned for delay, and because there was 
strong evidence that the exclusion was being 
abused by manufacturers who would provide a 
highe-than-normal rating to avoid the require- 
ments of the standard. PACCAR's expectation 
that few such vehicles are built because permits 
are required for loads of more than 24,000 
pounds on an axle is not to the point. It is not 
the gross vehicle weight on the highway that is 
controlling here, but simply the capacity of the 
axle installed by the manufacturer. In other 
words, the vehicle could obtain complete exclu- 
sion by the installation of heavy axles, whether 
or not they are ever used on the highway at full 
capacity requiring permit operation. 

Mack noted the many truck types {e.g., cement 
mixers, dump trucks) whose permits, if any. do 
not closely control the actual operation of the 
vehcile. As a practical matter, these vehicles 
operate in unrestricted operation with extremely 
heavy, and often liigh center-of-gravity. loads 
that necessitate extremely good braking. The 
agency continues to believe that an exclusion at 
this GAWR level is unjustified. The 29,000- 
pound exclusion reflects the larger vehicles with 
truly distinctive configiiration and more spe- 
cialized operation that justify special treatment. 



Mack, PACCAR, and the ATA also recom- 
mended extension of the exclusion for vehicles 
with two or more steerable axles with a GAWR 
of 16,000 pounds or more for each axle. No 
supporting data was presented and no other 
comments were received. In the absence of any 
supporting data the request is denied. 

The partial exclusion from the "no lockup" re- 
quirement in the case of "wheels other than the 
outermost on an axle system with more than 
four wheels" was supported without comment 
and is therefore made final. Rogers Brothei-s 
suggested that use of "axle system" to describe 
the row of wheels aci'oss the vehicle could be 
misleading. The agency's use of the term as 
part of its certification requirement to state "axle 
system" GAWR has not proved troublesome. 
On the basis of this experience, the terminology 
is made final as proposed. 

The TTMA suggested that the exclusion of 
certain logging and pulpwood trailers from the 
"no lockup" requirement be expanded to pennit 
them the same parking brake option as is pro- 
vided to agricultural commodity trailers. While 
not within the scope of this notice, the agency 
will consider this suggestion in its next parking 
brake proposal. 

While the Truck and Bus Safety Subcom- 
mittees did not take a position on the proposal, 
it is noted that their June 23, 1977, letter to 
Secretary Adams reaffirmed their earlier recom- 
mendations for revision of Standard No. 121. 

The economic impact of this nile has been 
considered and has been determined to be mini- 
mal. This is due primarily to the low i)roduc- 
tion volume both collectively and by individual 
firms and the brief leadtime remaining to make 
considerable design changes. This could even 
cause substantial adverse economic and financial 
impacts if these manufacturers were foi'ced to 
comply by the September 1, 1977, effective date. 
However, it has also been determined that the 
additional leadtime provided by this Final Rule 
should be sufficient to modify production lines 
whicli would incorporate the necessary design 
changes to accommodate the FMVSS 121 hard- 
ware. 



PART 571; S 121— PRE 98 



Effective: August 22, 1977 

In conwideration of the fore{join<r, Standard (Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 

No. 121 (49 CP'R 571.121) is amended. ... (15 U.S.C. 1392, 1407); delefration of autliority 

I^ffective date finding. Because these amend- at 49 CPR 1.50) 
ments relievo a restriction and do not create addi- Issued on Auirust 16 197"^ 

tional responsibilities for any person, it is found 
that an immediate effective date that advises 

manufacturers of the new requirements as soon Howard Dugoff 

as possible is in the public interest. Acting Administrator 

The program official and lawyer principally 
responsible for this rulemaking document are 42 F.R. 42208 

Duane Perrin and Tad lierlihy, respectively. August 22, 1977 



PART .■>71 ; S 121— PRE 09-100 



Effective: June 27, 1977 



PREAMBLE TO AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 14) 



The amendment extends indefinitely an exist- 
ing option for specialized agricultural trailers 
under Standard No. 121, Air Brake Systems, of 
meeting the parking brake requirements of the 
standard or the air-actuated "breakaway" re- 
quirements of the Bureau of Motor Carrier 
Safety. The option exists because the working 
environment of the trailers can lead to disabling 
of the parking brakes, and a solution to the 
underlying technical problems has not been per- 
fected. 

Date: Effective date June 27, 1977. 

Addresses: Petitions for reconsideration should 
refer to the docket number and be submitted to: 
Room r)108, Xassif Building, 400 Seventh Street, 
S.W., Washington, D.C. 20590. 

For Further Information Contact: 
Scott Shadle 

Office of Crash Avoidance 
National Highway Traffic Safety 

Administration 
Washington. D.C. 20r)90 (202) 426-0852 

Supplementary Information : Standard No. 121 
(49 CFR 571.121) permitted some bulk agricul- 
tural commodity trailers the option, until June .''O, 
1977, of meeting the parking brake requirements 
of the standard (actuation by an energy source 
unaffected by air loss in the service brake system) 
(S5.6..3) or the air-actuated "breakaway" system 
that complies with Bureau of Motor Carrier 
Safety (BMCS) requirements (49 CFR 393.43). 
Most manufacturers use the stored energy of a 
compressed spring to apply and maintain the re- 
quiied braking force recjuired ])y So. 6. 3. 

Manufacturers petitioned for modification of 
this parking brake recpiirement in the case of 
some agricultural trailers because they often are 



(Iroi)pe(l ori' near the fields by highway tractors 
and then towed into the fields by farm tractors. 
Tlie fai'm tractors do not have air compressors to 
recharge the air supply and release the brakes in 
order to move the vehicles. "Wlien the spring 
brakes are mechanically released to allow move- 
ment they may not be re-engaged for highway 
operation, permitting the trailer to operate on 
the highway without a .secondary means of brak- 
ing. To avoid the hazard of on-highway opera- 
tion with disengaged spring brakes, the agency 
adopted the option for a limited period. 

AVesco Truck and Trailer Sales petitioned for 
extension of the option to December 31, 1978, and 
Utility Trailer Manufacturing Company peti- 
tioned for its indefinite continuation. The agency 
has an outstanding jn-oposal to broaden the avail- 
able means to meet the parking and emergency 
brake requirements for all trailers (40 FR 56920; 
December 5, 1975). However, because of the 
comprehensive nature of the proposed revision, 
it will not be acted on in the immediate future. 

Until the broad proposal is made final or until 
another solution is available, the agency decided 
that the exclusion for these specialized trailers 
from the parking and emergency braking re- 
quirement sJiould continue, as long as the vehicles 
are manufactured to comply with the BMCS re- 
(luirements noted earlier. Accordingly, the agency 
proposed that the temporary exclusion contained 
in S5.6 and S5.8 of the standard be made perma- 
nent. 

All comments received on the proposal sup- 
ported continuation of the option. In the ab- 
sence of a satisfactory solution to the underlying 
technical problems, the agency has decided to 
make final the changes as proposed. 



PART 571; S 121— PRE 101 



EBeclive: June 27, 1977 



In consideration of the forefroinfr, Standard nient arc Scott Shadle and Tad Herlihy, respec- 
No. 121 (49 CFIl r)71.121) is amended. . . . tively. 

The economic and inflationary impacts of this (Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 

ruleinakin<r have been evaluated in accordance (1.") U.S.C. 1392, 1407); delegation of authority 
with 0MB Circular A-l()7, and an Economic at 49 CFR 1.50.) ' ■ 

Impact Statement is not required. Issued on June 27, 1977. 1 

The agency finds that this amendment may 
l)ec()iiie effective inunediately, because the contin- Joan Claybrook 

nation of the option relieves a restriction. Administrator 

The program official and lawyer principally 42 FR 33293 

responsible for the development of this amend- June 30, 1977 



I 



I 



PART 571; S 121— PRE 102 



Effective: March 23, 1978 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

(Docket No. 75-16; Notice 18) 



This amendment suspends the school bus service 
brake stopping distance requirements of Standard 
No. 121, Air Brake Systems, which were sched- 
uled for reimplementation April 1, 1978. This 
action is taken to preserve the status quo of the 
standard's applicabilitj' while more far-reaching 
issues of the air brake standard are resolved by 
the Department. 

Dates: The amendment is effective March 23, 
1978. Petitions for reconsideration must be re- 
ceived no later than April 24, 1978. 

For further information contact : 
Mr. Duane Perrin, Crash Avoidance Divi- 
sion, OtRce of Vehicle Safety Standards, 400 
Seventh Street, SW., Washington, D.C. 
20590 (202-426-2153). 

Supplementary information: Standard \o. 121 
(49 CFR 571.121) regulates the braking system 
performance of air-braked trucks, buses, and 
trailers. The standard has been in effect for 
trailers since January 1, 1975, and for trucks and 
buses since March 1, 1975. Following implemen- 
tation of the requirements for buses, a pattern of 
erratic beiiavior developed in the performance of 
the antilock system used by manufacturers of 
transit and intercity buses to satisfy the "no 
lockup" requirements of the standard (S5.3.1). 
The NHTSA suspended the service brake stop- 
ping distance requirement (including the "no 
lockup" requirement) for all buses to provide a 
period in which modified antilock hardware and 
newly-introduced systems could be field-evaluated 
(41 F.R. 1598; January 9, 1976). Several veliicle 
manufacturers and user groups argued that the 
suspension should be for a longer period and the 
suspension was extended from January 1, 1977, to 
September 1, 1977 (41 F.R. 52055; November 26, 
1976). and subsequently to January 1, 1978 (42 
F.R. 30188; June 13, 1977), with an additional 
3-month delay for school buses. 



The suspension of requirements for school 
buses is therefore scheduled to end April 1, 1978. 
While no school bus chassis or final-stage manu- 
facturer has petitioned for further delay of the 
"no lockup" requirement, two petitions for the 
exclusion of school buses from this requirement 
have been submitted by the users of school buses. 
The National Association for Pupil Transporta- 
tion petitioned for permanent exclusion of school 
buses on several grounds, including assertions 
about the unreliability, high costs, and difficulty 
of maintaining antilock systems. 

A second petition was recently filed jointly by 
the Transportation Director's Association of the 
State of Georgia, the County Superintendents of 
the State of Georgia, and the State Specification 
Committee of the State of Georgia. This petition 
requests exclusion of school buses from the entire 
standard, although the arguments for exclusion 
relate mainly to antilock system difficulties. 

Much of the information in both petitions ap- 
pears to be based on experience with systems 
manufactured during the first months of the 
standard's implementation, and does not take into 
account improvements and other changes in cir- 
cumstances since the bus service brake stopping 
distances were suspended in January 1976. Most 
notably, the extension of stopping distance re- 
quirements in March 1976 (41 F.R. 8783 ; March 1, 
1976) permits most school buses to be certified to 
S5.3.1 of the standard without the installation of 
antilock systems. Current manufacturer plans 
are for antilock to be standard equipment on 
about 18 percent of all school buses after the 
scheduled reimplementation of service brake stop- 
ping distance rcqtiirements. Approximately 85 
percent of these buses would have antilock only 
on the rear axle. 

The Department has initiated a series of actions 
that are intentled to resolve major concerns that 
have been raised with regard to the reliability, 



PART 571; S 121— PRE 103 



Effective: March 23, 1978 



effectiveness, and costs of the antilock systems 
generally used to meet the standard (42 F.R. 
9626; March 9, 1978). Given this initiative, it 
appears inappropriate to change the status quo as 
it affects the manufacturer of vehicles not pres- 
ently required to meet the stopping distance and 
"no lockup" recjuirements of So. 3.1. While there 
appears to be no independent basis in data or 
individual experience to indicate that the require- 
ments should not be reimplemented for school 
buses at this point, manufacturers that otherwise 
support the standard have counseled maintenance 
of the status quo for school buses while the other 
more major issues are resolved. This point was 
made in December 1977 by Ford as a major sup- 
plier of school bus chassis and by Bendix, a 
manufacturer of antilock systems. 

The NHTSA has therefore decided to tempo- 
rarily postpone reimplementation of the service 
brake stopping distance requirements of Standard 
No. 121 as they apply to air-braked school buses. 
The NHTSA solicits comment on the reestablish- 
ment of these requirements at a certain date and 
on what that date should be. The Motor Vehicle 
and Schoolbus Safety Amendments of 1974 (Pub. 
L. 93-492, October 27, 1974) and mail regularly 
received by the agency make clear that the public 
and their legislators advocate strong regulation 
of the safety systems on school buses. 

In accordance with Departmental procedures, 
the economic and other consequences of this rule- 
making have been evaluated. As the rule main- 
tains the status quo, it is not expected to have any 
new effects other than the inventory losses for the 



several school bus chassis manufacturers which 
do not also build trucks. These inventories could 
be utilized in response to purchase of antilock 
systems on an optional basis. 

In an unrelated matter, the agency takes this 
opportunity to delete 83.1.2 and the reference to 
it in S3.1, because it was a temporary provision 
of the standard that is no longer effective. 

Effective date finding: It is found that notice 
and public comment on this amendment are im- 
practical)le because of the extremely short time 
remaining before the requirement in question 
would otherwise become effective (April 1, 1978). 
Furthermore, it is found that the amendment may 
take effect sooner than 30 days following the date 
of its publication in the Federal Register be- 
cause it relieves a restriction. 

In consideration of the foregoing. Standard 
No. 121 (49 CFR 571.121) is amended as fol- 
lows. . . . 

The program oiRcial and lawyer principally 
responsible for this document are Duane Perrin 
and Tad Herlihy, respectively. 

(Sec. 103, 119, Pub. L. 89-.563, 80 Stat. 718 (15 
U.S.C. 1392, 1407) ; delegations of authority at 
49 CFR 1.50 and 501.8.) 



Issued on March 20, 1978. 



Howard Dugoff 
Acting Administrator 

43 F.R. 12015 
March 23, 1978 



i 



PART 571; S 121— PRE 104 



Effective: August 25, 1978 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 75-16; Notice 21) 



This notice fulfills the remand of the Xinth 
Circuit Court of Appeals in PACCAR v. No- 
torial Ilighicoy Trn^r Snfrty Adminisfrafion 
ami Drpnrfment of TrnnKportation -with repard 
to modification of test procedures, which is the 
only aspect of the order not subject to further 
judicial review. Test procedures and conditions 
are specified for frictional characteristics of the 
test track surface, duration of time intervals be- 
tween road tests, duration of pennissible wheel 
lockup during road tests, and the amount of 
curving in the test track. The agency also makes 
final a long-standing proposal to modify the 
means for establishing the frictional resistance 
of the road test surface. 

Dates: The amendment is effective August 25, 
1978. Petitions for reconsideration must be re- 
ceived no later tlian October 5, 1978. 

Address: Petitions for reconsideration should 
refer to the docket number and be submitted to : 
Docket Section. Room 5108. 400 Seventh Street, 
S.W., Wasiiington, D.C. :2G590. 

For further information contact: 
Tad Herlihy, Office of Chief Counsel; Na- 
tional Highway Traffic Safety Administra- 
tion, 400 Seventh Stivet. S.W., Wasiiington. 
D.C. 20590 (202-426-9511). 

Supplementary infoiiiiation : Standard Xo. 121 
(49 CFR 571.121) regulates the braking system 
jierformance of air-braked trucks, buses, and 
trailers. The standard has been in effect for 
trailers since January 1. 1975, and for trucks and 
buses since March 1, 1975. Requii-ements are es- 
tablislied for the service, emergency, and parking 
brake systems, including a requirement tliat the 
service brakes provide retardation, power and 



recovery capabilities. Road test procedures are 
set forth to advise manufacturers how the 
XHTSA will conduct its compliance tests of the 
manufacturers' products. 

In January 1975. a truck manufacturer peti- 
tioned foi- judicial review of the standard's pro- 
mulgation in accordance with § 105 of the 
Xational Traffic and Motor Vehicle Safety Act 
(15 U.S.C. 1394). The petitioner was "subse- 
quently joined by a trade association of truck 
users and a trade association representing the 
small manufacturers that complete trucks by 
mounting the bodies on incomplete truck chassis. 
The three actions were consolidated for argument 
in the Xinth Circuit U.S. Court of Appeals. 

The Xinth Circuit recently entered its order on 
the petition foi- review and remanded the stand- 
ard to tlie agency for further proceedings (573 
F.2d 632). The Federal government has since 
petitioned for review of two aspects of that order 
in the Supreme Court. The purpose of this no- 
tice is to set forth the agency's actions in fulfill- 
ment of the third aspect of the remand, which 
was not a subject of the govermnent's petition. 

The court remanded several issues to the agency 
concerning the standard's test procedures, all of 
which are easily resolved by modifications in the 
standard's wording which do not affect the re- 
(luirements for any person. The court stated that 
"the manufacturers are entitled to formal and 
reasonably specific testing criteria"' in the area of 
frictional characteristics of the test track surface, 
duration of time intervals between repetitive road 
tests, duration of permissible wheel lockup during 
stopping distance tests, and the amount of curv- 
ing in the test ti-ack. 



PART .571; S 121— PRE 105 



August 25, 1978 



Interpretation must be made of the court's re- 
mand on frictional characteristics of the test 
track. A first reading of tlie decision might sug- 
gest that a measurement teclinique (in the case, 
"the "skid number" method of measuring road 
surface friction) may not be used in standards 
setting if it does not produce exact measurements. 
It is acknowledged that the skid number measure- 
ment has an accuracy tolerance, and that the 
tolerance can vary from measurement to measure- 
ment for a variety of reasons. 

The agency does not believe the court intended 
this literal a reading, because no measurement can 
be exact as a matter of physical science. This 
exaggerated a reading of the decision would pre- 
clude all motor vehicle safety regulations, because 
all regulation involves measurement criteria and 
none is perfect. The agency's view is that the 
court objected only to reliance on a measurement 
technique that varies too widelj- in i-esponse to 
road surface conditions and that specified use of 
a no-longer-manufactured tire. 

Because the tire specified is no longer manu- 
factured, the XHT.SA has already replaced the 
skid number measurement in all of its stopping 
distance standards other than 121. The only 
reason the technique was not i-eplaced in kStand- 
ard Xo. 121 was to comply witli the Ninth Cir- 
cuit's wish that the standard ciiange as little as 
possible. (41 F.R. 24592; Jime 17, 1976). Now 
that review of the standard by the Ninth Circuit 
is complete, the agency can and does make final 
its longstanding proposal to use the new measur- 
ing technique. Conunents received with regard 
to Standard No. 121 were discussed in conjunc- 
tion with the June 1976 amendment. 

The court also stated that the margin of varia- 
tion in the measuring techniciue would not permit 
a manufacturer to conduct its tests by a means 
that ensured its vehicles would meet the require- 
ment set forth in the standard. While the agency 
has always taken the position that an exact value 
(such as "skid number 75") is the clear and un- 
ambiguous way to state a legal requirement so 
tluit manufacturers are best on notice of what 
performance is required (e.g., 40 F.R. 47141; 
October 8, 1975), the agency can instead state a 
range of skid numbers in such a way that the 
manufacturer will be able to test to the exact 



skid number encountered in its testing, Imowing 
that its vehicle has complied with the standard 
so long as the number used falls within the speci- 
fied range. Essentially, the test procedure can be 
restated as a range (representing the anticipated 
tolerance in the new measuring metliod) in which 
the manufacturer has its choice of wliat skid 
number it uses. As long as this range includes 
the criterion specified in the past by the NHTSA 
and is already being met by manufacturers, it is 
no more stringent that the past requirement. 
Similarly, the other skid numbers from which 
manufacturers could choose would fall in the 
range of those that tliey have been using pre- 
viously, but without the certainty that the chosen 
number will be the one by which their vehicles 
are measured. Tliis approach recognizes the 
physical impossibility of finding any measuring 
technique which is exact, and the agency finds 
that it accurately fulfills the court's remand. The 
skid number I'anges established are from 20 to 30 
for the wet surface, and from 71 to 81 for the dry 
surface, to reflect the different values obtained 
when the new test tires are used. It is noted that 
this revised specification of skid numbers is no 
more severe a requirement tlian the single values 
pi'eviously referenced in the standard. 

As for the remaining test conditions wliich the 
court questioned, the agency has monitored these 
conditions as a part of its compliance program 
and the tlevelopment of its compliance test pro- 
cedures. It is apparent tliat manufacturers, per- 
mitted to choose reasonable values for these 
aspects of the test protocol in the absence of cri- 
teria .set forth in the standard, have chosen values 
that fall within an easily adoptable level. No 
manufacturer, for example, has chosen to test on 
other than a straight test track, which is sensible 
in view of the fact that a straight track offers the 
easiest means of staying within a 12-foot-wide- 
lane. Comparably, no antilock manufacturer has 
chosen other than reasonable "wheel lockup'' 
times for its antilock systems because ov'erly long 
lockups significantly and adversely reduce the 
stopping performance of the brakes on the con- 
trolled axle, which would sacrifice the other 
major characteristics of the vehicle being meas- 
ured — that is, stopping distance. As for the in- 
terval between dynamic tests of the veliicle, the 
relevant factor is the relationship between the 



PART 571; S 121— PRE 106 



Augus* 25, 1978 



time interval and brake temperature, because a 
short interval could result in an adverse effect on 
brakinf;; capabilities due to fade or other thermal 
effects. Tlierefore, the NHTSA hereby adopts a 
specification for initial brake temperature, which 
will in turn determine the interval between tests. 
A review of XHTSA compliance test results has 
shown that the performance of all complying ve- 
hicles tested to date has been within tlie require- 
ments specified in this amendment. Adoption of 
tliese values therefore does not adversely affect 
any person subject to tlie standard, and they can 
be incorporated for tlie lienefit of remand witliout 
the delay occasioned by notice and opportunity 
for comment. 

The decision to revise the standard in this 
fashion has been evaluated in accordance with 
tlie requirements of Executive Order 12044 (43 
F.R. 12660; March 24. 1978) and the correspond- 
ing; review pi'ocedures within the Department of 
Transportation (43 F.R. 9582; March 8, 1978). It 
has been determined that this rulemaking is jrov- 
erned by short-term judicial considerations and 
that, despite its connection witli Standard Xo. 
121, does not qualify as a rulemakino; that raises 
issues of cost or controversy necessitating the 
level of review and connnent contemplated by the 
two directives. 



Effective date : "With regard to the establish- 
ment of a new test tire for pavement resistance 
measurement, because the older test tire is no 
longer manufactured, and because the amendment 
of the procedure and test tire is intended only to 
duplicate the existing procedure and tire, this 
amendment creates no additional requirements 
for any person, and an immediate effective date 
is found to be in the public interest. 

With regard to tlie modification of test proce- 
dures and conditions not based on a proposal, the 
agency finds that they do not impose additional 
requirements on any person, and that delay of a 
proposal is unnecessary and would be contrary to 
the public interest in responding to the court's 
remand as expeditiously as possible. 

In consideration of the foregoing, Standard 
Xo. 121 is amended. . . . 

The program official and lawyer principally 
responsible for this document are Duane Perrin 
and Tad Herlihy, respectively. 

(Sec. 103, 119. Pub. L. 89-563, 80 Stat. 718 (15 
U.S.C. 1392, 1407) ; delegation of authority at 49 
CFR 1.50.) 

Issued on August 25, 1978. 

Joan Claybrook 
Administrator 



PART 571: S 121— PRE 107-108 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 

Air Brake Systems 

(Docket No. 75-16; Notice 24) 



121 



Action: Final rule and interpretation of court 
decision. 

Summary: The U.S. Court of Appeals decision in 
PACCAE V. National Highway Traffic Safety 
Administration and Department of Transporta- 
tion invalidated aspects of Standard No. 121, Air 
Brake Systems. This notice advises interested 
persons of the agency's interpretation of the 
PACCAR holdings, to guide continuing compliance 
with the standard. This notice also amends the 
standard as specified by the court to provide for 
"due care" certification. 
Effective date: October 13, 1978. 
For further information contact: 

Tad Herlihy, Office of Chief Counsel, 
National Highway Traffic Safety Adminis- 
tration, 400 Seventh Street, B.W., Washing- 
ton, D.C. 20590 202-426-9511. 
Supplementary information: 

Standard No. 121 (49 CFR 571.121) regulates 
the braking system performance of air-braked 
trucks, buses, and trailers. The standard has been 
in effect for trailers since January 1, 1975, and for 
trucks and buses since March 1, 1975. 
Requirements are established for the service, 
emergency, and parking brake systems of these 
vehicles. Truck braking systems are a particularly 
critical safety system, due to large variations 
between the unloaded and loaded weight condi- 
tions and the generally higher weight of trucks 
compared to other vehicles on the highway. Major 
requirements of the standard are that vehicles stop 
in specified distances and that the wheels not lock 
uncontrollably during these stops. The "no lockup" 
requirement ensures that skidding due to wheel 
lockup and loss of lateral stability is minimized. 

In January 1975 a truck manufacturer petitioned 
for judicial review of the standard's promulgation 
in accordance with § 105 of the National Traffic 
and Motor Vehicle Safety Act (the Vehicle Safety 
Act) (15 U.S.C. § 1394) under which the standard 



was issued. Petitioner PACCAR was subsequently 
joined by a trade association of truck users and a 
trade association representing the small manufac- 
turers that complete trucks by mounting a body of 
specialized equipment on incomplete truck chassis. 
The three cases were consolidated for argument in 
the Ninth Circuit U.S. Court of Appeals. 

The court's decision was issued in April 1978 
(573 F2d 632, 9th Cir. 1978, Cert, denied October 
2, 1978), and the mandate making it effective was 
entered October 11, 1978. Certain aspects of the 
standard were invalidated, and the purpose of this 
notice is to set forth the agency's interpretation of 
the court's specified holdings to guide continuing 
compliance with the standard. One of the court's 
three holdings, that concerning test procedures 
and conditions, has already been responded to by 
the agency (43 FR 39390; September 5, 1978). 

Invalidation of Certain Stopping Distances 

While expressing support for requirements that 
"decreas[e] the disparity of stopping distances 
between ordinary automobiles and heavier 
vehicles" and maintain "vehicle stability and direc- 
tional control," the court was concerned about the 
safety of "heavier axles" in combination with the 
antilock systems used generally to provide "no 
lockup" performance. The court was concerned 
that a malfunctioning antilock system would allow 
wheel lockup of more aggressive front axle brakes 
more often or sooner than had been the case with 
weaker brakes, resulting in loss of steering con- 
trol. The court's emphasis on the combination of 
aggressive front axle brakes and antilock is clear in 
the opinion: 

As new components— strong front axles, new 
brake linings, and mini-computers to control 
wheel lock and skid— were mass-produced, and 
subsequently put together in a unique combina- 
tion, grave problems developed (emphasis 
supplied) 573 F2d at 641. 



PART 571; S 121-PRE 109 



In referring to "heavier axles", the court was 
describing the brake retardation levels supplied by 
manufacturers to obtain the 258-foot (and subse- 
quent 277-foot) 60-mph stopping distances 
specified by the standard prior to February 26, 
1976. The 60-mph stopping distances were ex- 
tended to 293 feet on that date (41 FR 8783; March 
1, 1976) and have resulted in significant reduction 
in retardation force levels. The court did not take 
this change into account, because the Record filed 
with the court and the July 1976 oral argument 
contained no information about the performance of 
the vehicles built after February 26th to conform 
to the 293-foot distance. The agency received no 
petitions for reconsideration of the brake force 
levels established by the March 1976 notice. 

The court held, with regard to stopping 
distances, 

. . . those parts of the Standard requiring 
heavier axles and the antilock device should be 
suspended. The evidence indicates that this 
can be accomplished if we hold, as we do, that 
the stopping distance requirements from 60 
mph are invalid . . . We hold only that more 
probative and convincing data evidencing the 
reliability and safety of vehicles that are 
equipped with antilock and in use must be 
available before the agency can enforce a 
standard requiring its installation. 573 F2d at 
643. 

These two statements of the holding differ from 
one another, the first specifying both "heavier 
axles" and "the antilock device" for invalidation, 
while the second only specifies antilock. The text of 
the opinion (located at footnote 26) indicates that 
the court actually equates "stopping distance" 
with "the antilock requirement." The agency 
concludes that the court intended to invalidate 
"the stopping distance requirements from 60 
mph" only insofar as a combination of high retar- 
dation force levels and a malfunctioning antilock 
would cause stability problems beyond those in 
vehicles built before the standard's effective date. 
At the same time the court was clear that the "no 
lockup" requirements were invalidated for both 
trucks and trailers. 

It is therefore the agency's view that the "no 
lockup" portions of S5.3.1 and S5.3.2 insofar as 
they apply to trucks and trailers are invalid, along 
with the related stopping distances of 293 feet for 
service brake capability and 613 for emergency 
brake capability (720 for truck-tractors in the 



unloaded condition) established for 60-mph loaded 
and unloaded stopping tests under S5.3.1 and S5.7 
for trucks. For those trucks with a speed attainable 
in 2 miles of less than 60 mph, the agency believes 
that the "top speed" stopping distance specified by 
S5.3.1.1 for both service brake and emergency 
brake stopping tests are invalid. 

The agency does not believe that any 
requirements of Standard No. 121 are invalidated 
for buses because of the court's statement in foot- 
note 1 that "[t]he part of the Standard that 
regulates air-braked buses is not at issue here." It 
is clear that the court was aware of the experience 
of buses built to conform to the standard, as 
evidenced by the court's reliance on statements by 
bus operators (footnote 43) and discussion of the 
rulemaking history for buses (text following foot- 
note 25). The court's explicit removal of bus 
requirements from its consideration seems a clear 
intent to limit the ambit of its decision to trucks 
and trailers. 

The agency concludes that only the actual stop- 
ping distances from 60-mph (or top speed) are 
invalidated and not other requirements that bear 
on performance of the vehicle. This understanding 
of the court decision fulfills the court holding cited 
above, while it does not disturb braking 
characteristics which do not present potential 
adverse handling characteristics. Thus, the stop- 
ping test sequence in which the truck or trailer 
must remain within a 12-foot lane from 60 mph (or 
top speed) is not invalid, while the requirement to 
stop within a specified distance is invalid. 

The dynamometer requirements of S5.4 for 
trucks and trailers also were not affected by the 
court's holding. It does appear that the require- 
ment for 90 p.s.i. air pressure in the trailer control 
line during the stop constitutes a portion of the "no 
lockup" requirement and is therefore invalidated 
by the court. Collateral requirements such as air 
reservoir volume that may be indirectly based on 
"no lockup" performance are not affected by the 
court decision. 

A secondary reason to conclude that the testing 
from 60 mph remains in the test sequence is that 
manufacturers must continue to certify compliance 
with 20-mph stops and x parking brake test follow- 
ing certain 60-mph stops. The 60-mph stops affect 
the brake linings and could affect results of other 
portions of the testing if they are dropped from the 
test sequence. 



PART 571; S 121-PRE 110 



With regard to the invalidated portions of the 
standard, the agency expects to pubhsh a Federal 
Register notice shortly that sets forth its plans. 

"Due Care" Certification 
The court expressed concern about the certifica- 
tion responsibilities of the "final stage" manufac- 
turers that mount the body or specialized equip- 
ment on mass-produced truck chassis built by other 
manufacturers. Section 114 of the Vehicle Safety 
Act (15 U.S.C. § 1403) specifies that the manufac- 
turer or distributor of a motor vehicle shall certify 
that its product conforms to all applicable Federal 
motor vehicle safety standards. The agency has 
issued regulations that divide the responsibility for 
certification of "multistage" vehicles among the 
"incomplete vehicle manufacturers" of the chassis, 
any "intermediate stage" manufacturer involved, 
and the "final stage" manufacturer that completes 
the vehicle (49 CFR Parts 567, 568). 

Standard No. 121 sets forth performance 
requirements that air-braked vehicles must 
conform to, and further sets forth the testing 
conditions under which the performance must be 
met (paragraph S6, Conditions). The requirements 
include a specification that certain stopping and 
wheel control capabilities be available under 
certain conditions, including stops from 60-mph 
and 20-mph in the unloaded and loaded conditions. 
The standard does not require that manufacturers 
subject their vehicles to these stops. It is accepted 
that the smaller final-stage manufacturers may not 
in all cases have the resources and capabilities to 
conduct such testing. The agency has regularly 
stated that a manufacturer may meet its statutory 
certification requirements either through 
demonstration of the specified stops or by any 
other chosen means that fulfills the related 
statutory requirement that a manufacturer must 
exercise "due care" in certification (15 U.S.C. 
§ 1397(bX2)). The agency has not stated to any 
final-stage manufacturer what its "due care" 
responsibility might consist of, in recognition of 
the reality that "due care" is essentially a judicial 
concept that is determined on a case-by-case basis 
in light of the factual situation facing the particular 
manufacturer at the time of certification. Because 
the engineering and financial resources available 
to a particular manufacturer are not fixed, what 
constitutes "due care" would vary among 
manufacturers, and even vary from day-to-day for 
the same manufacturer, making such a statement 
by the agency impracticable. 



The court was sympathetic to the situation of the 
smaller final-stage manufacturer in holding that— 
. . . Since NHTSA has admitted that road 
testing is beyond the practical and financial 
reach of the final stage manufacturers, it must 
propose some alternative method for those 
manufacturers which, if followed, it will 
recognize as fulfilling the due care require- 
ment. 573 F2d at 645. 

Fortunately, an alternative to road testing does 
exist that would constitute "due care" in certifica- 
tion by any final-stage manufacturer that adopted 
it, whatever its resources and engineering exper- 
tise. Parts 567 and 568 obligate the incomplete 
vehicle manufacturer to provide a basis for com- 
plete certification (the "incomplete vehicle docu- 
ment") with each vehicle, which can be used for 
certification as long as the final-stage manufac- 
turer does not violate an "envelope" of conditions 
listed in the document as the reasonable limits to 
which the incomplete vehicle manufacturer has 
already tested. A final-stage manufacturer can 
avoid any road testing simply by a "pass through" 
of this incomplete vehicle document. Of course, it 
would be a logical impossibility for the agency to 
specify what constitutes "due care" for the infinite 
number of configurations that exceed the 
"envelope" of conditions in advance of the 
manufacturer's decision to do so. 

The problem, as noted by the court, is that the 
final-stage manufacturer only had assurances from 
the agency in the past that conformity to the 
incomplete vehicle document would constitute the 
exercise of due care in complying with Standard 
No. 121. What is required by the court's holding, in 
the agency's view, is the modification of Standard 
No. 121 itself to state a certification of compliance 
based on adherence to the incomplete vehicle docu- 
ment would constitute the exercise of due care. 
This is accomplished by this notice. 

It is recognized that trailers and buses other than 
school buses are typically manufactured in one 
stage and this alternative method is unavailable to 
these vehicles. However, the court's holding 
discusses only the obligations of final-stage 
manufacturers that, by definition, only exist in the 
case of multistage manufacture. 

In accordance with Department of Transporta- 
tion policy for the analysis of regulatory actions, it 
is found that the amendment concerning due care 
does not constitute a significant regulation that 
requires regulatory analysis. Evaluation of the 



PART 571; S 121-PRE 111 



change indicates that it will have no economic 
effects other than a potential reduction of certifica- 
tion costs for some final-stage manufacturers. 

Findings. Because the amendment constitutes 
an alternative method of compliance and creates 
additional requirements for no person, it is found 
for good cause shown that notice and opportunity 
for comment are unnecessary and that an effective 
date sooner than 30 days from the date of publica- 
tion is in the public interest. The court's holding 
with regard to "no lockup" and stopping distances 
take effect independently of administrative action 
by the agency. 

In consideration of the foregoing, paragraph S6 
of Standard No. 121 (49 CFR 571.121) is amended 
by the addition of a sentence at the end of the text 
to read as follows: 



"Compliance of vehicles manufactured in two or 
more stages may, at the option of the fmal-stage 
manufacturer, be demonstrated to comply with 
this standard by adherence to the instructions of 
the incomplete vehicle manufacturer and any 
intermediate-stage manufacturer provided with 
the vehicle in accordance with § 568.4(aX7Xii) and 
§ 568.5 of Title 49, Code of Federal Regulations." 

The program official and lawyer principally 
responsible for the development of this document 
are Duane Perrin and Tad Herlihy, respectively. 



Issued on October 13, 1978. 



Joan Claybrook 
Administrator 
43 F.R. 48646 
October 19, 1978 



PART 571; S 121-PRE 112 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 

(Docket No. 75-16; Notice 25) 



Action: Final rule. 

Summary: This notice amends the air brake stand- 
ard to further extend existing exclusions for heavy 
hauler trailers, auto transporters, and other 
specialized vehicles from certain requirements and 
withdraws two recent changes in road test 
procedures. These actions follow judicial review of 
the standard, and are intended to provide direction 
with regard to the future of the air brake standard. 

Dates: Effective date of amendments is December 
18, 1978. 

Addresses: Petitions for reconsideration should 
refer to the docket number and be submitted to: 
Room 5108, Nassif Building, 400 Seventh Street, 
S.W., Washington, D.C. 20590. 

For Further Information Contact: 

Mr. Duane Perrin, Office of Vehicle Safety 
Standards, National Highway Traffic Safety 
Administration, Washington, D.C. 20590 (202) 
426-2153. 
Supplementary Information: Standard No. 121, 
Air Brake Systems (49 CFR 571.121); regulates 
the braking system performance of air-braked 
trucks, buses, and trailers. The standard has been 
in effect for trailers since January 1, 1975, and for 
trucks and buses since March 1, 1975. Re- 
quirements are established for the service, 
emergency, and parking brake systems of these 
vehicles. 

Test Procedures 

Certain aspects of the air brake standard were 
invalidated by court action in PACCAR v. National 
Highway Traffic Safety Administration and 
Department of Transportation, 573 F2d. 632 (9th 

Cir. 1978), cert, denied U.S. 

(October 2, 1978) (47 U.S.L.W. 3190 (Sup. Ct.)) as 
detailed in a recent agency notice (43 FR 48646; 
October 19, 1978). The agency fulfilled the court's 
remand with regard to modification of test 
procedures on August 25, 1978 (43 FR 39390; 



September 5, 1978), by means of several amend- 
ments. Notice and opportunity for comment were 
not provided, because the NHTS A judged that the 
modifications would not involve additional 
requirements for any person and reinstitution of 
the test procedures was found to be in the public 
interest. However, six petitions for reconsidera- 
tion of some of the modifications have been filed by 
parties that argued the changes may or do in fact 
cause some changes in the standard's 
requirements. 

In response to the court's order for a specific 
criterion for the interval between repetitive tests, 
the standard was amended to specify initial brake 
temperatures prior to the tests. Brake 
temperatures are partly a function of the time that 
brakes have to cool between tests. 

Freightliner Corporation objected to the 
specification of a 150° to 200°F. initial brake 
temperature for stopping tests as the agency's 
method of establishing the test intervals. 
Freightliner explained that some of its brake 
designs could not provide the required 60-mph 
stopping distances if initial brake temperatures 
were above 180°F. The other commenters, in 
contrast, pointed out that metallic linings and disc 
brake technology argued for a higher initial brake 
temperature in some cases. The American Truck- 
ing Associations (ATA) suggested specification of 
a time period between repetitive tests as a means 
of fulfilling the court remand for test intervals. 

In view of these possible substantive changes 
represented by the specification of an interval 
between repetitive road tests, the agency 
concludes that the wisest course of action would be 
to revoke the initial brake temperature specifica- 
tion and propose a new method, following 
consideration of the data and suggestions supplied 
by manufacturers. Withdrawal of the test interval 
specification is accomplished in this notice. 



PART 571; S 121-PRE 113 



All petitioners requested that the modification of 
skid number specification be reconsidered. The 
agency met the court's objection to specification of 
a single value for the "skid resistance" 
characteristics of the test track by substitution of a 
range of permissible values. Commenters differed 
significantly with the agency both over the mean- 
ing of the court's opinion and the consequence of 
the modification adopted by NHTSA. Although the 
NHTSA does not believe that its modification had 
a substantive effect on the requirements of the 
standard, it is clear that there is a difference of 
opinion about the court's holding, and the NHTSA 
again considers the wisest course of action to be 
revocation of the skid number range to permit a 
proposal and opportunity for comment. The 
substitution of the updated and uncontroversial 
ASTM test method and tire is not revoked. 

No other aspect of the test procedure modifica- 
tions was cited by commenters as a source of 
specific concern. 

As for the period of time that the skid number 
range and initial brake temperature requirements 
were in effect (from August 25th to the date of 
publication of this notice), the agency hereby states 
that it will not pursue cases that arose as a conse- 
quence of these requirements during the short 
period that they were effective. 

Vehicle Exclusions 

Auto transporters and heavy hauler trailers have 
been excluded from Standard No. 121 until 
January 1, 1979, due to the distinctive construction 
or use of these vehicles that make compliance with 
certain aspects of the standard more difficult. Four 
years of additional time were granted to manufac- 
turers of these vehicles in order for them to work 
out solutions to their distinctive equipment 
problems. The Truck Trailer Manufacturers 
Association (TTMA) recently petitioned the 
NHTSA for permanent exclusion of heavy hauler 
trailers from the standard, based on hardware 
problems and related reasons. 

The NHTSA proposed some continued exclu- 
sions for these and related vehicle types (43 FR 
41056; September 14, 1978). The nature of the 
proposed exclusions was based on equipment space 
considerations, rough terrain use of some of the 
vehicles, and most importantly, on the uncertainty 
over future road testing requirements created by 
pendency of the Ninth Circuit litigation. It was 
accordingly proposed that heavy hauler trailers 
and auto transporters be temporarily excluded 



from stopping distance requirements, including 
the "no lockup" and related reservoir size 
requirements. Also, heavy haulers, pulpwood 
trailers, and straddle trailers would be permitted 
the same option as agriculture trailers and 
converter dollies have to meet only the emergency 
breakaway requirements and no parking brake 
requirements. 

The proposed temporary exclusions from the 
road test and reservoir volume requirements were 
supported by Freightliner and General Motors, 
manufacturers of tractors for auto transporter 
use, and by Delavan Industries, Inc., an auto 
transporter manufacturer. The California 
Highway Patrol (CHP) and Wagner Electric Co., a 
brake component manufacturer, expressed 
concern that the exclusions not be made perma- 
nent, and that these vehicles eventually be 
required to exhibit the same performance as other 
air-braked trucks and trailers. No date for 
compliance was suggested. TTMA requested a 
review of the reservoir volume requirements for all 
vehicles in light of the PACCAR decision, and 
suggested a reduced volume requirement for 
trailers. No other comments on these subjects 
were received. 

This amendment makes final the temporary 
exclusions from road test and reservoir volume 
requirements for heavy hauler trailers and auto 
transporters. No termination date for the exclu- 
sions was proposed or is made in the final rule, but 
manufacturers of these vehicles must be and are 
hereby placed on notice that these exclusions are 
not made as permanent exclusions. The temporary 
exclusions will therefore remain in effect until a 
final decision is made regarding the reservoir 
volume and stopping distance requirements for all 
vehicles. Notice and opportunity for comment will 
precede any amendment of the reservoir volume 
and stopping distance requirements. 

The CHP requested rewording of the exclusion 
of auto transporter tractors from the road test 
requirement in S5.7.1, to avoid confusion over the 
reference to such requirements in S5.7.3. The 
wording is changed to expand the exclusion to both 
S5.7.1 andS5.7.3. 

The proposed permanent exclusion from the 
parking brake requirements for heavy hauler 
trailers was supported by TTMA and Fontaine 
Truck Equipment Co., a heavy hauler trailer 
manufacturer. The CHP expressed the desire that 
the exclusion be only temporary, and be reviewed 



PART 571; S 121-PRE 114 



in the future when more compact parking brake 
designs are available. The National Automobile 
Transporters Association (NATA), and two auto 
transporter manufacturers, Delavan and Cottrell- 
Sullivan, requested permanent exclusion from the 
parking brake requirement for auto transporter 
trailers as well. Reasons cited were the problems 
of mounting the parking brake components and the 
associated air reservoirs without loss of cargo- 
carrying capacity, lack of availability of more 
compact hardware, and the short lead time to 
redesign equipment by January 1, 1979. NATA 
also noted that auto transporters usually operate 
as married units, and have a good safety record. 
Another manufacturer, Traffic Transport 
Engineering, requested permanent exclusion from 
the entire standard, based on the same arguments. 

The NHTSA is aware that auto transporter 
manufacturers are presented with difficult hard- 
ware packaging problems related to parking 
brakes on trailers, but is also aware that prototype 
auto transporters have been built to full 
compliance with the standard about two years ago. 
This constitutes strong evidence that such systems 
can be built on a production basis, and the agency 
takes note that manufacturers of auto transporters 
have had four years longer to solve their hardware 
problems than manufacturers of other types of 
trailers. 

Nevertheless, the agency also recognizes that 
the availability of new, more compact parking 
brake systems is dependent on the proposed 
changes in the parking and emergency brake 
requirements, which have not yet been 
implemented. Some additional delay of applica- 
bility of the parking brake requirement for auto 
transporters therefore appears reasonable. An 
additional delay of one year is provided, with the 
expectation that any changes in the parking brake 
requirements will be made final by early 1979, 
allowing sufficient lead time for manufacturers to 
incorporate such changes in their trailers. 
Requests for permanent exclusion from the park- 
ing brake requirements or the entire standard for 
auto transporters are denied, on the grounds that 
it has been demonstrated that complying vehicles 
can be designed without significant loss of cargo 
carrying capacity, and that the additional year's 
exclusion should compensate for any lead time 
difficulties. Unlike heavy hauler trailers, auto 
transporter trailers are not subjected to the same 
off-road environment that formed the basis for 
excluding certain vehicle types from the parking 



brake requirement. The proposed parking brake 
exclusion of heavy hauler and other trailers is 
adopted as proposed. 

TTMA and three of its members— Birmingham 
Manufacturing Co., Ferree Trailer Corp., and 
Fontaine Truck Equipment Co.— repeated their 
requests for permanent exclusion from the entire 
standard for heavy hauler trailers, and expressed 
dismay that all of the points raised in their petition 
for exclusion had not been addressed in the pre- 
amble to the agency's proposal. The NHTSA 
regrets the brevity of its treatment of the issues in 
the proposal, but it should not be interpreted as a 
lack of attention or concern for the problems of the 
heavy hauler industry. A detailed discussion of the 
petition and comments to the proposal is being 
prepared. Copies will be sent to the TTMA and 
parties who commented on the proposal, and 
placed in the public docket. Because of its length 
and technical nature, it is only summarized here. 

To place the subject in perspective, it is 
necessary to first see what portions of the stand- 
ard apply to heavy hauler trailers. Section S5.1 and 
S5.7 of the standard apply only to trucks and 
buses. By this notice, heavy hauler trailers have 
been permanently excluded from S5.6, and 
temporarily excluded from S5.3 and parts of S5.2. 
Section S5.5 applies only if the trailer is antilock- 
equipped, which is not required according to the 
Ninth Circuit decision. To the NHTSA's 
knowledge all heavy hauler trailers already are 
compljnng with the applicable portions of S5.2 and 
S5.8, because of industry standards or BMCS 
requirements. Thus the only remaining 
requirements that could necessitate any change in 
the vehicles are the dynamometer requirements of 
S5.4. 

The assertion that is presented in the TTMA 
petition, and repeated in the comments to the 
proposal, is that compliance with Standard No. 121 
will necessitate the addition of more axles, 
resulting in substantially increased cost. This 
possibility arises because of the current method of 
rating the capacity of heavy hauler trailers. Axle 
weight ratings (GAWR's) depend upon the load- 
carrying capacity of the axle, rims, and tires, and 
the torque capability of the brakes on the axle. 
According to industry standards, tires can be rated 
for higher loads if speed is restricted. Current 
practice is to rate heavy hauler trailers according 
to the capacity of the axles and tires, using the tire 
load capacity ratings at 20 mph. The brakes used 



PART 571; S 121-PRE 115 



are currently not considered in axle rating calcula- 
tions for the restricted speed rating. 

For a trailer subject to Standard No. 121, 
however, the dynamometer requirements of S5.4.1 
require that the brake retardation capability be 
proportional to the GAWR's. If the retardation 
capability of the brakes on a trailer is insufficient 
to meet the minimum performance requirement, a 
manufacturer must either install more powerful 
brakes or "derate" the axles to bring the GAWR's 
in line with the braking capability afforded. In the 
case of heavy hauler trailers, manufacturers say 
that they are already using the most powerful 
brakes available for 15-inch wheels, and those 
brakes are rated at only 17,000 pounds per axle. 
The manufacturers assert that since nearly all 
heavy hauler trailer axles are currently rated for a 
higher load, the derating to 17,000 pounds per axle 
necessitated by consideration of brakes in the 
rating calculations would require them to add more 
axles to provide the same overall capacities for 
their trailers. 

The data supplied, however, do not support this 
view. The dynamometer tests are run at 50 mph, 
and therefore the 17,000-pound axle rating for 
brakes is a factor in determining the GAWR at 
that speed. Examination of the load ratings of the 
tires typically used on heavy hauler trailers 
(8.25 x 15 and 9.00 x 15) show that their ratings at 
50 mph are below 17,000 pounds per axle. 
Therefore, the tires are the limiting element in 
determination of GAWR at 50 mph, and the brakes 
currently being used on these trailers already 
comply with the dynamometer requirements of the 
standard with the tires employed. 

The misunderstanding apparently arises from 
the current practice of rating heavy hauler trailers 
at 20 mph. It is noted that while § 567.4(hX3) of 
NHTSA certification regulations (49 CFR Part 
567) allows manufacturers to specify GVWR- 
GAWR ratings for operation of a vehicle at 
restricted speeds in addition to the unrestricted 
ratings, the GAWR used for determination of 
compliance with the dynamometer requirements 
must be that corresponding to a speed not less than 
the dynamometer test speed (50 mph). Testing at 
the restricted speed GAWR would represent an 
overloaded condition at the dynamometer test 
speed. The portion of the dynamometer test condi- 
tions dealing with GAWR (S6.2.1) is hereby 
amended to clarify this fact. The only trailers that 
would actually have to be derated (at 50 mph) 



would be those using 10.00 x 15 or 11.00 x 15 tires. 
Very large heavy hauler trailers (over 50 ton 
capacity) are not affected because they are already 
permanently excluded by virtue of having a gross j 
vehicle weight rating over 120,000 pounds. i 

In view of the longer than anticipated time for 
response to the TTMA petition and the short time 
remaining before the existing January 1979 effec- 
tive date, the NHTSA has decided to and hereby 
delays the effective date for institution of the 
dynamometer requirements for heavy hauler 
trailers to July 1, 1979, as requested by TTMA. 

CHP suggested changing the word 
"agriculture" to "agricultural" in the definition of 
a commodity trailer, and deletion of the phrase "an 
arrangement of air control lines and reservoirs 
that minimizes damage in field operation" because 
it is vague. Midland-Ross commented that straddle 
trailers would be included in the agricultural 
commodity trailer definition, and that a separate 
definition is unnecessary. CHP suggested that the 
term "logging trailer" be used instead of 
"pulpwood trailer", and that the definition be 
reworded to be similar to the definition of 
agricultural commodity trailer. CHP also 
suggested deleting the reference to hydraulic 
lifting arms in the case of straddle trailers, because 
it is too design restrictive. The NHTSA agrees 
with the spirit of these suggestions but, in the 
interests of preserving continuity in interpretation 
of existing terminology, the changes are only made 
where they do not conflict with wording already in 
the standard or in previous interpretations of it. 

It is noted that the comments on the parking and 
emergency brake aspects of the September 14th 
notice have convinced the NHTSA that further 
consideration should precede rulemaking changes 
in this area. 

In accordance with Department of Transporta- 
tion policy for the analysis of regulatory actions, it 
is found that these amendments of Standard No. 
121 do not have significant impact as defined in the 
Department's criteria for internal review. The 
changes all permit greater manufacturing flexi- 
bility and do not impose any additional 
requirements. The implementation of some of the 
standard's requirements for heavy hauler trailers 
and auto transporters reflects the termination of 
an exclusion, not new agency action. It is also 
found that no significant adverse environmental 
impact will result from these amendments. 



PART 571; S 121-PRE 116 



In consideration of the foregoing, Standard No. 
121 (49 CFR 571.121) is amended 

Effective date finding: Due to the short time 
remaining before vehicles would have to be 
modified to comply with the established January 
1979 requirements, it is found that notice and 
opportunity for comment on the delay of the 
dynamometer requirements for heavy hauler 
trailers to July 1, 1979, and the parking brake 
requirements for auto transporter trailers to 
January 1, 1980, is impracticable and contrary to 
the public interest in establishing the final 



requirements as early as practicable. For the same 
reason, it is found to be in the public interest to 
make the relieving amendments effective 
immediately. 

The program official and lawyer principally 
responsible for the development of this document 
are Duane Perrin and Tad Herlihy, respectively. 

Issued on: December 11, 1978. 

Joan Claybrook 
Administrator 
43 F.R. 58820 
December 18, 1978 



PART 571; S 121-PRE 117-118 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems — Interpretative Amendment 
(Docket No. 75-16; Notice 26) 



Action: Final rule. 

Summary: This notice amends the lan^ua^e of 

Air Brake Standard 121 to reflect the U.S. Court 

of Appeals decision in PACCAR v. Nntionol 

Highway Tra^c Safety Admini'it ration and 

Department of T ranHportat'ioti. This action is 

intended to clear up any confusion about the 

effect of the court's decision on portions of tlic 

standard. 

Effective date: August f). 1970. 

For further information contact: 

Roger Tilton, Office of Chief Counsel, 
National Highway Traffic Safety Adminis- 
tration, 400 Seventh Street. S.W.. Wasli- 
ington, D.C. (202-426-9511). 

Supplementary information: Standard No. 121 
(49 CFR .571.121) regulates the braking system 
performance of air-braked trticks. buses, and 
trailers. The standard has Ijeen in effect since 
January 1975 for trailers and Marcli 1975 for 
trucks and buses. Petitions for judicial review 
of the standard were filed and resulted in in- 
validation of three aspects of the air l)rake regu- 
lation (see PACCAR \. NETS A and DOT. 573 
F.2d 632. Cir. 1978. cert denied. October 2, 1978). 
The agency explained its interpretation of the 
court's action in three Federal Register notices 
(4.3 FR .39.390. September 5. 1978; 43 FR 48646. 
October 19. 1978; 43 FR 58820, December 18. 
1978) and in several meetings held with equip- 
ment and vehicle manufacturers and air-lirakc 
vehicle users. 

It has become apparent that some confusion 
exists with regard to the agency's interpretatioii 
of the comljined effect of two aspects of the 
court's decision. The first is the agency's view 
that the court in\-alidated the "no lockup'' por- 



tions of S5.3.1 and S5.3.2 insofar as they apply 
to trucks and trailers, along with the related 
stopping distances of 293 feet for service brake 
capability and 613 feet for emergency brake 
capability (720 for truck-tractors in the un- 
loaded condition) established for 60-mph loaded 
and unloaded stopping tests under S5.3.1 and 
So. 7 for trucks. The second is the agency's view 
that the court invalidated the "skid number'' 
measurement technique of test surface frictional 
characteristics foi- use in measuring whether 
trucks meet the sti-ict stopping distance require- 
ments of the standard. The Court found that 
while the "skid numliei'" of a surface is an olijec- 
tive measurement, it is not a practicable test 
method for manufacturers since normal fluctua- 
tions for a given load surface would require 
manufactures to o\eicompensate by testing their 
vehicles on road surfaces sul)stantially slicker 
than the regulation rei|uires. The agency acted 
to correct the skid numlier variability problem 
and measurement technifpie but subsequently 
withdrew the correction as it I'clated to skid 
number variability liecause of disagreement both 
over the meaning of tiie coui't's opinion and the 
consequences of the modification adopted (43 
FR .58820; December 18. 1978). 

Several references by the agency to the fact 
that the court did not invalidate stopping dis- 
tance requirements other than the 60-mph stops 
for trucks have apparently been taken to mean 
that the agency is in a position to enforce com- 
pliance with all icmaining stopping distances. 
The fact that the standard's stopping distances 
remain completely valid for buses may contribute 
to this view. Tn fact, the court's remand to the 
agency of the skid number specification and dura- 
tion of time interval between repetitive road 



PART 571; S 121-PRE 119 



tests effectively precludes the agency from en- 
forcinfr compliance with any road test re(iiiiic- 
ment for trucks and trailers at any speed on wet 
or dry surfaces. It is apparent tliat amendment 
of the lanofuaire of tlu' standard to reflect the 
court's actions would be lieneficial to end any 
confusion that may exist. Tlie i)uri)()sc of thi> 
notice is to maivc tiiat amendment. 

It is noted that tiiis action lias no effect on 
the requirements for huses. or on the application 
and release timinjj:. d3-namometei'. oi' parkinu' 
brake requirements for all vehicles. Foi- this 
reason, the XHTSA is not amending the test 
procedures which are applicable to vehicles or 
requirements othei- than those addi-esscd by the 
court. 

The agency is amending tlie a[)[)lication sec- 
tion of the standard to state that trucks and 
trailers need not comply with ceitain paragrajihs 
of the regulation. T\w i-egulation is being 
amended in this manner rather than deleting oi- 
revising the woi'ding of each of the affected 
sections in order to disturb the actual text of 
the standard as little as possilile. In that way. 
the affected sections can most easily be reinstated 
when suitable solutions to the requirements laid 
down by the Court ai'e found. In addition, by re- 
taining the standard's language in its existing 
form, manufacturers are made aware of what 
the agency still considers to be I'easonable stand- 
ards for minimum acceptable pei'formance. and 
those manufacturers that wish to construct their 
vehicles in accoi-dance with the non-mandatoi'v 



sections of the standard will have the necessary 
guidance to do so. The agency also has taken 
this opportunity to delete from .*>;> references to 
temporary exclusion- «liic]i ha\'e expired. 

Effectivi' ildfc fihiliiKj: The agency is is.-uing 
an interpretatixe amendment that merely con- 
forms that -tandard",- language to its meaning 
following the remand by the Ninth Circuit, and 
tlierefnre the amendment does not change the 
standard in any respect. Accoi'dingly. it is found 
for good cause shown that notice and oppor- 
tunity for conmient are unnecessary and that an 
effective date for the aiuendments sooner than 
;>() days from the date of pnbliration in the 
Fi<Ji ral R((jht( r i.- justified. 

In consideration of the foregoing. Standard 
No. \-l\ (49 CFK .■)71.1-J1) is amended by i-eplac- 
ing the last paragrapli of S:') with tlie followim:' 
paragraph : 

Xotwithstanding any language lo the contrary, 
sections S5.3.1. S.").:;.!.!. ^:^:.\:l. S."i.:i.-.^.l. ^:^:-\:l:l. 
S;').?.! and S.").?.:) of this standard are not a|ipli- 
cable to trucks and trailers. 

The program official and lawyei' principally 
i'esponsil)le for the de\elopment of this document 
are Duane Perrin and Roger Tilton. respecti\ely. 

Issued on : August :i 1979. 

.loan Claybrook 
-Vdministrator 

44 F.R. 46849 
August 9, 1979 



PART 571; S 121-PRE 120 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 121 



Air Brake Systems 
(Docket No. 75- 

Action: Final rule. 

Summary: This notice amends the air l)rake 
standard to expand the latitude whicli a ve- 
hicle manufacturer has in selectintr means to 
comply with the parking brake requirements. 
The amendment makes final one of .several 
chanjies to the parkinp and emergency brake re- 
quirements that had been proposed previously. 
The other proposed chan<res liave been reexamined 
in lifrlit of conunents to the proposal and to a 
separate proposal outlininjr plans for replace- 
ment of FMVSS 121 by a new standard. . The 
XHTSA has decided to suspend rulemakin<r 
action on those items until research results and 
other furtlier information is available. 
Effective date: August 9. 1979. 
For further information contact: 

^Ir. Duane Perrin. Office of Crash Avoidance. 
\ational Hifrhway Traffic Safety Adminis- 
tration. Washinoton. D.C.. 20590 (202-12fi- 
21.53). 

Supplementary inforynation : Standard No. 121 
(49 CFR .571.121) re<rulates the brakin.s: system 
performance of air-braked trucks, buses, and 
trailers. The standard has been in effect for 
trailers since January 1. 1975. and for trucks and 
buses since ^larch 1. 1975. The standard con- 
tains requirements for service brake systems, 
emergency brake systems, and parking brake 
systems. 

Sloi'e than four years' experience with tlie 
standard on the part of manufacturers, users, the 
agency, and other interested parties indicate a 
possibility that some of the emergency and park- 
ing brake performance requii'ements could be 
more broadly stated to allow new design options 
that offei- a level of safety e(]uivalent to tliat 



— Parking Brakes 
16; Notice 27) 

offered by existing designs. On September 14. 
1978, the XHTSA issued a notice of proposed 
rulemaking (43 FR 41()5f)) that would liave sub- 
stantially revised the pai'king lirake I'equirements 
for all vehicles and the emergency brake require- 
ments for ti-ailers. .Subsequent to the issuance 
of that proposal, a mandate was issued by the 
U.S. Court of Appeals for the Xinth Circuit, in- 
validating cei'tain aspects of P^MVS.S 1-Jl (43 
FR 4S64fi. October 19. 197s). In liglit of the 
court decision, tlie XHT.SA lias tentatively de- 
cided to issue a new lieavy duty veliicle brake 
standard. FMV.^.S 130. wliich will eventually 
replace FMVS.S 121. An Advance Xotice of 
Proposed Rulemaking (AXPR^I) on .Standard 
Xo. 130 was issued in February (44 FR 9783, 
February 15, 1979). 

Responses to the AXPRM on Standard Xo. 
130 underscored the need for stability in the 
industry. To achieve stability, commenters sug- 
gested avoiding unnecessaiy changes in .Standard 
Xo. 121. which remains in effect until FMV.SS 
130 is issued. In addition, commenters on the 
September notice pointed out areas where some 
of the proposed changes need further research 
and consideration. For these reasons, most of 
the changes to the parking and emergency brake 
sections of .Standard Xo. 121 that wei'e proposed 
in September are being tentatively i)ut aside. 
Some of the changes proposed in the .September 
notice may be raised again in the new proposal 
for .Standard Xo. 1.30. after further information 
is ol)tained by tlie agency. 

The XHTSA has determined, however, that 
one of the proposed changes should not be de- 
layed until rulemaking is completed on FMVSS 
130. That change allows the application of park- 
ing brakes bv means of service brake air. as long 



PART 571; S 121-PRE 121 



as the application can be made when a faihtre 
exists in tlie service l)rake system, and as lon^- 
as the parkin<i- brake is lield in tlie applied posi- 
tion by mechanical means. The standard pre- 
vionsly reqiiired parking brakes to be applied 
by a separate enerizy source, and this change 
allows an alternatixe to the s})rin<;-applied park- 
ino- brake systems now used. The alternative 
systems could be less costly and ha\c essentially 
the same performance as current systems. Tn 
addition, the chan<;e allow- more comi)act sys- 
tems to be produced for vehicles such as auto 
transporters where space for mountini;' of com- 
ponents is at a premium. 

The chanp-es to the parkinp- brake a|)plication 
requirements proi)osed in Sei)teml)er (Docket 
Xo. 7.5-16; Notice •22) were oppo.sed by the Cali- 
fornia Hishway Patrol (CUP), on the assump- 
tion that a diaphrafrm inside a brake chamber 
is considered part of the Intake chamber housing. 
and that the proposal would have allowed a re- 
duction in safety over current systems. Previous 
interpretations, however. ha\e clarified tliat a 
brake chamber housing is only the outer body 
of the chamber and does not include the dia- 
phrao-m. Thus, the prescribed performance nnist 
be achieved with any type of failure in the serv- 
ice brake system, includinir a ruptured dia- 
phragm. The XHTSA concludes, therefore, that 
this interpretation satisfies the concerns of the 
CUP. The CUP also supiiested a sliiiht reword- 
in<r to indicate that tlie i-equired foive is applied 
at the drawbar and not in the parking brake 
itself. The wording has been changed somewhat 
to clarify that point. 

The American Truckin<r Associations (ATA) 
and Transquip Industries objected to the pro- 
posal because it would require a second reservoir 
on an air-applied parking brake system in order 
for the pai'kin.'i' bi-akes to be applied in the event 
of a failure of the service reservoir. The 
XHT.SA miderstands that the use of only one 
reservoii- would reduce cost. However, it would 
also offer a si<rnificant reduction in pei'formance 
as compared to present systems, because certain 
service brake system failures could occur for 
which there would be no secondary means of 
brakinsr the vehicle. Accordin<rly. the XHTSA 
concludes that .VTA and Transcpiip Industries' 



objections do not warrant any chanjre in the 
amendment. 

Traffic Transport Enjiineerinp. an auto trans- 
porter manufacturer. re(iuested clarification of 
whether two relay valves would be required in 
an air-applied system, since the parking brakes 
would ha\e to be capable of application with 
any single failure, and the relay valve could fail. 
Since relay valve failures are relati\ely conunon. 
the XHT.SA considers it necessary to preserve 
the performance achieved by present systems. 
Currently, the failure of a relay \alve would 
not pre\ent emergency application of the trailer 
brakes. Thus, if a manufacturer chooses to 
e(|uip a trailei- with air-ai)plied parkinjx brakes, 
he would lune to de\ise a means of achieving 
a brake application in ca.se of failure of the serv- 
ice brake relay \'alve. That could be accom- 
plished 1)V usiuir a second relay \alve and reser- 
\<)ir. 

The Dolphin Brake Corporation asked for 
clarification of the proposed wording to deter- 
bine whether or not theii- parking brake that 
applies by means of hydi'aulic fluid would meet 
the requirements. The XITTS.V believes that the 
wording is sufficiently clear to indicate tliat. like 
an air-applied system, such a brake would only 
meet the requirements if a mechanical means of 
holding the application in the e\ent of loss of 
fluid pi'essnre weie incorporated. 

Tn order to minimi/-e thanpes to FATVSS 1'21. 
the amended wordin<^ for application and hold- 
ing;' will remain in one paragraph. S5.6.8. as cur- 
rently in the standard. 

.Since this amendment relieves a i-estriction it 
is beinp made effective innnediately. 

In consideration of tlie forepoinp. the first 
sentence of paragraph .S.".. ()..'! of Standard Xo. 
121 (40 CFR .".Tl.l-Jl) is amended .... 

The principal authors of this notice are Duane 
Perrin of the Office of Clash .Vvoidance and 
Roper Tilton of the Office of Chief Counsel. 

Issued on .Vupust (\ 1979. 

Joan Claybrook 
Administrator 

44 F.R. 46850 
August 9, 1979 



PART 571; S 121-PRE 122 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 121 



(Docket No. 75- 

Action: Correction. 

Summary : On Aiifjust 9, 1970. tlie XHTSA \mh- 
lished in the Federal Reghter ;i final rule aiiieiul- 
ing the applicability section (S3) of Standanl 
No. 121. Air Brake Sysfema. That notice, whicii 
added a sentence to the end of S.3, contained 
an error in its reference to section S5.7.3. The 
notice appears to show that the entire section of 
S5.7.3 no longer applies to trucks and trailei's. 
when the agency intended only for subpara- 
graphs (a) and (b) to be inapplicable to trucks 
and trailers. These vehicles do have to comply 
with S5.7.3(c). Accordingly, the August 9 
notice is corrected by changing the last sentence 
of section S3 to read : Xotwithstanding any lan- 
guage to the contrary, sections Sr).3.1. Sr).3.1.1. 



Air Brake Systems 

16; Notice 28) 

S5.3.2, S5.3.2.2, S.5.7.1. S5.7.3(a) and S5.7.3(b) 



of this standard ai'c not applicable to truclcs and 
ti-ailers. 

K-jfrct'tve (laic: September 13. 1079. 

For further in format ion contart : 

Mr. Scott Shadle, Office of Crash Avoidance, 
Xational Highway Traffic Safety Adminis- 
tration. AVashington. D.C. 20500 (O02_+26- 
2ir.3). 

Issued on September 4. 1979. 

Michael M. P'inkelstein 
As.sociate Administrator for 
Rulemalcing 

44 F.R. 53166 
September 13, 1979 



PART 571; S 121-PRE 123-124 



PREAMBLE TO AMENDMENT TO 
MOTOR VEHICLE SAFETY STANDARD NO. 



121 



Action: Final rule; correction. 



Summary: On Au<rust 9, 1979. the XHTSA piil.- 
lished in the Federal Register a final rule aiiieml- 
m^ the applicability section (S3) of Standard 
Xo. 121, .1?'?' Brake SyafemH. On Septeniher 13, 
the agency publislied a r(ji-iection of tliat final 
rule. An error was made in the September 13. 
correction wlien reference to section So. 3. 2.1 was 
inadvertently- deleted from the notice. . Accord- 
innrly, the final rule is corrected l)y chanfrinfr tlie 
last sentence of section S3 to read : Xotwith- 
standing any language to the contrary, gg 5.3.1. 
5.3.1.1. 5.-3.2. 5.3.2.1, 5.3.2.2. 5.7.1. 0.7.3(a) and 
5.7.3(b) of this standard are not applicable to 
trucks and trailers. 



Air Brake Systems — Correction 
(Docket No. 75-16; Notice 29) 

Effective date : October 1. 1979. 
For fiirfhir hifoniKifioti coiifurf : 

Mr. .Scott ShadU". Office of Cra^li Avoitlance. 
Xational lliginvay Traffic Safety Adminis- 
tration. Washiiigloii. D.C. 2(Ci9() (2()l'-426- 
21.")3). 

Issued on .September 25. 1079. 



^lichael M. Finkelstein 
Associate Administrator for 
Rulenuiking 

44 F.R. 57100 
October 4, 1979 



PART 571; S 121-PRE 125-126 



PREAMBLE TO AN AMENDMENT TO 

FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121 

Air Brake Systems 
(Docket No. 79-03; Notice 4) 



ACTION: Final rule. 

SUMMARY: This notice amends Standard No. 121, 
Air Brake Systems, to require trucks, buses and 
trailers equipped with air brakes to have service 
brake systems acting on all wheels. This amend- 
ment is being made in response to reports from 
several manufacturers that some trucks and 
trailers were soon to be constructed without front 
axle brakes. The agency concludes that such a 
change would result in a serious downgrading 
of existing brake systems and, accordingly, 
issues this amendment to prevent this from hap- 
pening. 

EFFECTIVE DATE: This amendment is effective July 
24, 1980 

FOR FURTHER INFORMATION CONTACT: 

Mr. John Machey, Crash Avoidance Division, 
National Highway Traffic Safety 
Administration, 400 Seventh 
Street, S.W., Washington, D.C. 20590 
(202-426-1714) 

SUPPLEMENTARY INFORMATION: On October 18, 
1979, the agency published a notice of proposed 
rulemaking (44 FR 60120) proposing the implemen- 
tation of a small part of a new safety standard. 
Standard No. 130, Heavy Duty Vehicle Brake 
Systems. The agency has also issued two ANPRMs 
relating to long- and short-term rulemaking issues 
concerning Standard No. 130. Resolution of the 
issues raised in those notices will occur after all 
necessary agency research and analyses have been 
completed. The October 18 notice, which was very 
limited in its scope, proposed the implementation 
of a requirement that heavy duty vehicles have 
brakes acting on all wheels. The requirement was 
proposed in response to a developing problem that 
was brought to the agency's attention by both 



vehicle and equipment manufacturers concerning 
front axle brakes. 

Standard No. 121, Air Brake Systems, formerly 
required trucks and trailers to comply with certain 
stopping distances and other road test require- 
ments. To achieve these requirements, trucks and 
trailers were equipped with front axle brakes 
which aid significantly in improving vehicle stop- 
ping capability. However, in PACCAR v. NHTSA, 
573 F.2d, 632 (9th Cir. 1978) cert, den'd 439 U.S. 
862, the road test requirements were invalidated 
as they apply to trucks and trailers. In light of this 
development, several manufacturers tentatively 
decided to remove front axle brakes as a way to 
reduce slightly the costs associated with the pro- 
duction of heavy duty vehicles. 

When the agency discovered that manufacturers 
intended to remove front axle brakes, the NHTSA 
reexamined data available to it concerning the ef- 
fect that such a removal of brakes would have upon 
the capability of these vehicles to make safe stops. 
The results of this examination, which were de- 
tailed in the proposal and which are available in 
the docket, lead the agency to conclude that the 
removal of front axle brakes increases a vehicle's 
stopping distance. The amount of this increase 
depends upon the type of vehicle, the vehicle 
loading and the effectiveness of its remaining 
brake systems. Sometimes the increase in stopping 
distances is substantial. 

The agency considers any increase in the stop- 
ping distance of heavy vehicles to be contrary to 
the interests of safety. Existing heavy duty 
vehicles equipped with front axle brakes already 
have longer stopping distances than many smaller 
vehicles on the road. This disparity in the stopping 
distances between large and small vehicles in- 
creases the likelihood of accidents between 
vehicles when both are involved in emergency 
braking maneuvers. To permit a reduction in the 
braking capabilities of heavy vehicles, that would 



PART 571; S121-PRE 127 



result in exacerbating the disparity between the 
stopping distances of heavy and lighter vehicles, 
could result in an increased risk of accidents to the 
occupants of both vehicle groups. To prevent the 
downgrading of heavy vehicle brake systems, the 
agency issued its notice of proposed rulemaking to 
require brakes acting on all wheels. 

Sixteen comments were received in response to 
the notice of proposed rulemaking. Most of the 
commenters concurred with the agency's attempt 
to prevent the downgrading of heavy duty vehicle 
brake systems. However, many of the commenters 
raised minor objections to the manner in which the 
proposed action was to be taken. 

The largest single complaint from the com- 
menters concerning the proposal was that it would 
implement only a small portion of a new safety 
standard. Many commenters suggested that the 
agency should not implement any part of that 
standard (Standard No. 130) until all research has 
been completed and the agency is prepared to 
issue the standard in its entirety. In connection 
with this comment, several manufacturers sug- 
gested that the proposed amendment would be 
more appropriately placed in Standard No. 121. 

Manufacturers argued the merits of amending 
Standard No. 121 rather than implementing Stand- 
ard No. 130 in several ways. First, they argued 
that by implementing Standard No. 130 in a 
piecemeal fashion, the agency is subjecting itself to 
many of the criticisms that have surrounded 
Standard No. 121. Therefore, they suggested that 
the agency defer action on Standard No. 130 until a 
complete standard can be issued. Further, they 
stated that the implementation of a new safety 
standard would increase paperwork and would re- 
quire changes in certification labels and incomplete 
vehicle documents. They suggest these changes 
would add costs and would require extending the 
leadtime before the proposed requirement could 
become effective. On the other hand, manufac- 
turers stated that an amendment of Standard No. 
121 would not require them to change certification 
labels or modify incomplete vehicle documents. 
This would lower the costs associated with the pro- 
posal. Also, the leadtime for implementing a 
change in Standard No. 121 would be minimal. 

In response to the manufacturers first argument 
that no portion of Standard No. 130 should be im- 
plemented until the entire standard is ready for 
issuance, the agency disagrees. Currently, the 



NHTSA is conducting several research programs 
concerning heavy duty vehicle brakes. Some of this 
rulemaking is long-term while some is short-term. 
The agency contemplates implementation of some 
portions of the short-term rulemaking actions prior 
to obtaining information on all of its long-term 
rulemaking goals. This is the typical rulemaking 
process for many of the agency's standards. It is 
not in the interest of safety to defer short-term 
safety gains while waiting for the results of long- 
term safety rulemaking. 

The agency is more persuaded by the manufac- 
turers's second argument that implementation of a 
portion of Standard No. 130 at this time would un- 
necessarily impose additional paperwork burdens 
upon manufacturers, whereas amending Standard 
No. 121 to accomplish the same result would not in- 
crease their paperwork burdens. As the NHTSA 
indicated in the notice proposing this amendment, 
the agency seeks only to maintain the existing 
quality of braking systems. Whether this goal is 
achieved by amending Standard No. 121 or im- 
plementing part of Standard No. 130 is not impor- 
tant to the agency. However, since manufacturers 
would prefer amending Standard No. 121 and since 
implementing part of Standard No. 130 would be 
more costly, the agency agrees with those com- 
menters who would prefer an amendment of Stand- 
ard No. 121, and that standard is amended by this 
notice. Several commenters objected to the pro- 
posal on the grounds that it was a design standard 
rather than a performance standard. These com- 
menters suggested that the agency should delay 
amendments implementing any requirements until 
the correct performance requirements are 
developed. The agency disagrees. 

All of the agency's safety standards affect 
design choices to some degree. The very setting of 
any performance standard implies some narrowing 
of design choice. Although the agency attempts to 
minimize the effect, in some instances a significant 
limitation on design is necessary to secure a par- 
ticular type of safety improvement. Standard No. 
121 does not differ from other safety standards in 
its effect on design. It uses performance re- 
quirements although some elements of design are 
restricted. Even though this amendment increases 
slightly the standard's effect on design choice, the 
standard remains performance oriented. Further, 
the effect of the old standard was to require brakes 
acting on all wheels. Although this amendment is 



PART 571; S121-PRE 128 



more specific in that requirement, the result is 
the same. Commenters should note that the 
agency is not specifying the design of the brakes 
that must be used on each wheel. Accordingly, 
the NHTSA concludes that this amendment does 
not substantially or unnecessarily affect design 
and allows manufacturers significant flexibility in 
the design and improvement of their braking 
systems. 

As a result of the PACCAR decision and the 
resulting possibility of brake performance down- 
grading, the agency is forced to take immediate 
corrective action. The PACCAR decision raised 
questions concerning the stopping distance re- 
quirements for trucks and trailers. The Court 
urged the agency to reexamine its stopping dis- 
tance requirements and to ensure the propriety 
of any requirement that might be reimposed. In 
response, the agency has commenced exploratory 
rulemaking to determine the appropiate stopping 
distances for trucks and trailers. When the 
rulemaking is completed, it is contemplated that 
stopping distance requirements will be reim- 
posed. The agency cannot reimpose those re- 
quirements until the research is completed. Given 
the absence of stopping distance requirements 
for trucks and trailers, and the time required for 
reimplementing stopping distances and the im- 
mediate problem of brake system downgrading, 
the agency must adopt a more expedient ap- 
proach to prevent the existing levels of safety in 
heavy-duty vehicle brakes from being reduced. 

Kelsey-Hayes supported this rulemaking ac- 
tion but at the same time requested an inter- 
pretation of an entirely unrelated section of 
Standard No. 121. Unrelated requests for inter- 
pretations should not be included with docket 
comments on a specific proposal. The agency will, 
however, respond to Kelsey-Hayes by a letter or 
in a separate notice. 

In accordance with Executive Order 12044, the 
agency has reviewed the impacts of this proposed 
amendment and has determined that it is not 
significant. Since the amendment will merely re- 
quire manufacturers to continue to manufacture 
vehicles as they are doing currently, the costs 
associated with this amendment will be minimal. 
Further, the agency has adopted the manufac- 
turers' suggestions to incorporate this amend- 
ment in Standard No. 121 to further minimize the 
possibility of any increased costs. 



Since this amendment imposed no additional 
burdens upon any manufacturer and only re- 
quires manufacturers to continue existing 
manufacturing practices and since it is in the in- 
terest of safety to prohibit as soon as possible the 
manufacture of vehicles without front axle 
brakes, the amendment is effective 45 days after 
publication in the Federal Register. In the notice 
proposing this amendment, commenters objected 
to an immediate effective date especially if the 
amendment were made in Standard No. 130. Com- 
menters indicated that more time would be re- 
quired to change certification labels. Since the 
amendment is being incorporated into the ex- 
isting Standard No. 121, the agency considers 
these objections to the effective date to be no 
longer valid. Nonetheless, the agency is giving 45 
days of leadtime to ensure that all manufacturers 
have ample time to comply with the re- 
quirements. 

In accordance with the foregoing. Volume 49 of 
the Code of Federal Regulations, Part 571 is 
amended by revising Standard No. 121, Air Brake 
Systems, as follows: 

1. A new paragraph S5.1.8 is added to 49 CFR 
Part 571.121 to read: 

S5.1.8 Brake distribution. Each vehicle shall be 
equipped with a service brake system acting on 
all wheels. 

2. A new paragraph S5.2.2 is added to 49 CFR 
Part 571.121 to read: 

S5.2.2 Brake distribution. Each trailer shall be 
equipped with a service brake system acting on 
all wheels. 

The principal authors of this notice are John 
Machey of the Crash Avoidance Division and 
Roger Tilton of the Office of Chief Counsel. 

Issued on June 2, 1980. 



Joan Claybrook 
Administrator 

45 FR 38380 
June 9, 1980 



PART 571; S121-PRE 129-130 



I 



MOTOR VEHICLE SAFETY STANDARD NO. 121 



Air Brake Systems— Trucks, Buses and Trailers 
(Docket Nos. 70-16, 70-17; Notice No. 2) 



51 . Scope. This standard establishes perform- 
ance and equipment requirements for braking 
systems on vehicles equipped with air brake 
systems. 

52. Purpose. The purpose of this standard is 
to insure safe braking performance under normal 
and emergency conditions. 

53. Application. This standard applies to 
trucks, buses, and trailers equipped with air 
brake systems. However, it does not apply to: 

(a) Any vehicle that has an overall vehicle 
width of more than 102 inches with extendable 
equipment in the fully retracted position; 

(b) Any vehicle equipped with an axle that 
has a gross axle weight rating (GAWR) of 
29,000 pounds or more; 

(c) Any truck or bus that has a speed attain- 
able in 2 miles of not more than 33 mph; 

(d) Any truck that has a speed attainable in 
2 miles of not more than 45 mph, an unloaded 
vehicle weight that is not less than 95 percent 
of its GVWR, and no capacity to carry occu- 
pants other than the driver and operating crew; 

(e) Any trailer that has a gross vehicle weight 
rating GVWR of more than 120,000 pounds 
and whose body conforms to that described in 
the definition of "Heavy hauler trailer" set forth 
in S4; 

(f) Any trailer that has an unloaded vehicle 
weight which is not less than 95 percent of its 
GVWR; and 

(g) Any load divider dolly. 

In addition, the standard does not apply to a 
heavy hauler trailer manufactured before Jan- 
uary 1, 1979; any vehicle manufactured before 
January 1, 1979, that, in combination with 



another vehicle, constitutes a part of an auto 
transporter; and any vehicle manufactured be- 
fore September 1, 1977, that has a GAWR for 
any axle of 24,000 pounds or more, or two or 
more front steerable axles with a GAWR of 
16,000 pounds or more for each axle. 

S4. Definitions. 

"Air brake system" means a system that uses 
air as a medium for transmitting pressure or 
force from the driver control to the service brake, 
but does not include a system that uses com- 
pressed air or vacuum only to assist the driver in 
applying muscular force to hydraulic or me- 
chanical components. 

"Antilock system" means a portion of a serv- 
ice brake system that automatically controls the 
degree of rotational wheel slip at one or more 
road wheels of the vehicle during braking. 

"Auto transporter" means a truck and a 
trailer designed for use in combination to trans- 
port motor vehicles, in that the towing vehicle 
is designed to carry cargo at a location other 
than the fifth wheel and to load this cargo only 
by means of the towed vehicle. 

"Heavy hauler trailer" means a trailer with 
one or more of the following characteristics: 

(1) Its brake lines are designed to adapt to 
separation or extension of the vehicle frame; 
or 

(2) Its body consists only of a platform 
whose primary cargo-carrying surface is not 
more than 40 inches above the ground in an 
unloaded condition, except that it may include 
sides that are designed to be easily removable 
and a permanent "front-end structure" as that 
term is used in (^ 393.106 of this title. 



PART 571; S 121-1 



"Initial brake temperature" means the average 
temperature of the service brakes on the hottest 
axle of the vehicle 0.2 miles before any brake 
application. 

"Load divider dolly" means a trailer com- 
posed of a trailer chassis and one or more axles, 
writh no solid bed, body, or container attached, 
and which is designed exclusively to support 
a portion of the load on a trailer or truck ex- 
cluded from all the requirements of this stand- 
ard. 

"Skid number" means the frictional resistance 
of a pavement measured in accordance with 
American Society for Testing and Materials 
Method "E-274-70 (as revised July 1974)" at 40 
mph, omitting water delivery as specified in para- 
graphs S7.1 and 7.2" of that method. 

"Speed attainable in two miles" means the 
speed attainable by accelerating at maximum rate 
from a standing start for two miles on a level 
surface. 

S5. Requirements. Each vehicle shall meet 
the following requirements under the conditions 
specified in S6. 

S5.1 Required equipment— truclts and buses. 

Each truck and bus shall have the following 
equipment: 

55.1.1 Air Compressor. An air compressor of 
sufficient capacity to increase air pressure in the 
supply and service reservoirs from 85 pounds per 
square inch (psi) to 100 (psi) when the engine 
is operating at the vehicle manufacturer's maxi- 
mum recommended rpm within a time, in seconds, 
determined by the quotient 

actual reservoir capacity x 25 
required reservoir capacity 

55.1.2 Reservoirs. One or more service reser- 
voir systems, from which air is delivered to the 
brake chambers, and either an automatic con- 
densate drain valve for each service reservoir or 
a supply reservoir between the service reservoir 
system and the source of air pressure. 

S5.1.2.1 The combined volume of all service 
reservoirs and supply reservoirs shall be at least 
twelve times the combined volume of all service 
brake chambers at maximum travel of the pistons 
or diaphragms. 



55.1.2.2 Each reservoir shall be capable of 
withstanding an internal hydrostatic pressure of 
five times the compressor cutout pressure or 500 
p.s.i., whichever is greater for 10 minutes. 

55.1.2.3 Each service reservoir system shall be 
protected against loss of air pressure due to 
failure or leakage in the system between the 
service reservoir and the source of air pressure, 
by check valves or equivalent devices whose 
proper functioning can be checked without dis- 
connecting any air line or fitting. 

55.1.2.4 Each reservoir shall have condensate 
drain valve that can be manually operated. 

S5.1.2.3 Towing vehicle protection system. If 

the vehicle is intended to tow another vehicle 
equipped with air brakes, a system to protect the 
air pressure in the towing vehicle from the effects 
of a loss of air pressure in the towed vehicle. 

55.1.4 Pressure gauge. A pressure gauge in 
each service brake system, readily visible to a 
person seated in the normal driving position, 
that indicates the service reservoir system air 
pressure. The accuracy of the gauge shall be 
within plus or minus 7 percent of the compressor 
cut-out pressure. 

55.1.5 Warning signal. A signal, other than 
a pressure gauge, that gives a continuous warn- 
ing to a person in the normal driving position 
when the ignition is in the "on" or "run" position 
and the air pressure in the service reservoir sys- 
tem is below 60 psi. The signal shall be either 
visible within the driver's forward field of view, 
or both audible and visible. 

55.1.6 Antilock warning signal. A signal on 
each vehicle equipped with an antilock system 
that gives a continuous warning to a person in 
the normal driving position when the ignition is 
in the "on" or "run" position in the event of a 
total electrical failure of the antilock system. 
The signal shall be either visible within the 
driver's forward field of view or both audible, 
for a duration of at least 10 seconds, and con- 
tinuously visible. The signal shall operate in the 
specified manner each time the ignition is re- 
turned to the "on" or "run" position. 

55.1.7 Service brake stop lamp switch. A 

switch that lights the stop lamps when the service 



PART 571; S 121-2 



brake control is statically depressed to a point that 
produces a pressure of 6 psi or less in the service 
brake chambers. 

S5.1.8 Brake distribution. Each vehicle shall be 
equipped with a service brake system acting on all 
wheels. 



S5.2 Required equipment— trailers. 

shall have the following equipment: 



Each trailer 



55.2.1 Reservoirs. One or more reservoirs to 
which the air is delivered from the towing vehicle. 

55.2.1.1 A reservoir shall be provided that is 
capable, when pressurized to 90 psi, of releasing the 
vehicle's parking brakes at least once and that is 
unaffected by a loss of air pressure in the service 
brake system. 

55.2.1.2 Total service reservoir volume shall be 
at least eight times the combined volume of all serv- 
ice brake chambers at maximum travel of the 
pistons or diaphragms. 

55.2.1.3 Each reservoir shall be capable of 
withstanding an internal hydrostatic pressure of 
500 p.s.i. for 10 minutes. 

55.2.1.4 Each reservoir shall have a condensate 
drain valve that can be manually operated. 

55.2.1.5 Each service reservoir shall be pro- 
tected against loss of air pressure due to failure or 
leakage in the system between the service reservoir 
and its source of air pressure by check valves or 
equivalent devices. 

55.2.2 Brake distribution. Each trailer shall be 
equipped with a service brake system acting on all 
wheels. 

S5.3 Service brakes— road tests. The service 
brake system on each truck and bus shall, under the 
conditions of S6.1, meet the requirements of S5.3.1, 
S5.3.3, and S5.3.4 when tested without adjustments 
other than those specified in this standard. The 
service brake system on each trailer shall, under the 
conditions of S6.1, meet the requirements of S5.3.2, 
S5.3.3, and S5.3.4 when tested without adjustments 
other than those specified in this standard. How- 
ever, the truck and trailer portions of an auto 
transporter (if both are manufactured after January 
1, 1979) shall, in combination, meet the require- 
ments of S5.3.1 as they apply to a single unit truck 
or bus, in place of the requirements of S5.3.2 as they 
apply to the trailer portion, and in place of the re- 



quirements of S5.3.1 as they apply to the truck por- 
tion in the loaded condition. 

S5.3.1 Stopping distance— trucks and buses. 

Except for a school bus when stopped six times for 
each combination of weight, speed, and road condi- 
tion specified in S5.3.1.1, in the sequence specified 
in Table I, the vehicle shall stop at least once in not 
more than the distance specified in Table II, 
measured from the point at which movement of the 
service brake control begins, without any part of the 
vehicle leaving the roadway and without lockup of 
any wheel at speeds above 10 mph except for 

(a) Controlled lockup of wheels of not more than 
one second allowed by an antilock system, or 

(b) Lockup of wheels on nonsteerable axles other 
than the two rearmost nonliftable, nonsteerable 
axles on a vehicle with more than two nonsteerable 
axis. 

TABLE I 
STOPPING SEQUENCE 

1. Burnish 

2. Control traOer service brake stops at 60 mph 
(for truck-tractors tested with a control trailer 
in accordance with S6.1.10.6). 

3. Control trailer emergency brake stops at 60 
mph (for truck-tractors tested with a control 
trailer in accordance with S6.1.10.7). 

4. Stops with vehicle at gross vehicle weight 
rating: 

(a) 20 mph service brake stops on skid number 

range 71-81. 
(h) 60 mph service brake stops on skid number 

range 71-81. 

(c) 20 mph service brake stops on skid number 
range 20-30. 

(d) 20 mph emergency brake stops on skid 
number range 71-81. 

(e) 60 mph emergency brake stops on skid 
number range 71-81. 

5. Parking brake test with vehicle loaded to 
gross vehicle weight rating. 

6. Stops with vehicle at unloaded weight plus 
500 lb.: 

(a) 20 mph service brake stops on skid number 
range 71-81. 



PART 571; S 121-3 



(b) 60 mph service brake stops on skid number 
range 71-81. 

(c) 20 mph service brake stops on skid number 
range 20-30. 



on 



,(d) 20 mph emergency brake stops 
number range 71-81. 

(e) 60 mph emergency brake stops on 
number range 71-81. 



skid 



skid 



7. Parking brake test with vehicle at unloaded 
weight plus 500 lb. 

S5.3.1.1 Stop the vehicle from 60 m.p.h. and 
20 mph on a surface with a skid number in 
the range of 71 to 81, and from 20 mph on a 
wet surface with a skid number in the range 
of 20 to 30, with the vehicle (a) loaded to its 
gross vehicle weight rating, and (b) at its un- 
loaded vehicle weight plus 500 pounds (including 
driver and instrumentation). If the speed at- 
tainable in 2 miles is less than 60 mph, the ve- 
hicle shall stop from a speed in Table 11 that is 
4 to 8 mph less than the speed attainable in 2 
miles. 

Table II.— Stopping Distance in Feet 



Vehicle- 



Service Brake 
stopping distance 



Emergency Brake 
stopping distance 



speed 


Column 1 


Column 2 


Column 3 


Column 4 


in 


Skid 


Skid No. 


Skid No. 


71-81 


miles 


Skid No. 


20-20 






per hour 


71-81 








20 


35 


60 


83 


85 


25 


53 




123 


131 


30 


75 




170 


186 


35 


101 




225 


250 


40 


131 




288 


325 


45 


165 




358 


409 


50 


203 




435 


504 


55 


246 




520 


608 


60 


293 




613 


720 



S5.3.2. Stopping capability— trailers. When 
tested at each combination of weight, speed, and 
road condition specified in S5. 3.2.1, in the se- 
quence specified in Table I, with air pressure of 
90 psi in the control line and service reservoir 
system and with no application of the towing 
vehicle's brakes, a trailer shall stop without any 
part of the trailer leaving the roadway and with- 



out lockup of any wheel at speeds above 10 mph, 
except for 

(a) Controlled lockup of wheels of not more 
than one second allowed by an antilock 
system; or 

(b) Lockup of wheels on nonsteerable axles 
other than the two rearmost nonliftable; 
nonsteerable axles on a trailer with more 
than two nonsteerable axles; or 

(c) In the case of an axle system having more 
than four wheels, lockup of any wheel 
other than the outermost wheel at each 
end of the axle system. 

55.3.2.1 Stop the vehicle from 60 m.p.h. and 
20 mph on a surface with skid number in the 
range of 71 to 81, and from 20 mph on a wet 
surface with a skid number in the range of 20 
to 30, with the vehicle (a) loaded to its gross 
vehicle weight rating, and (b) at its unloaded 
vehicle weight plus 500 pounds (including in- 
strumentation). 

55.3.2.2 When stopped in accordance with 
S5.3.2., any trailer designed exclusively for har- 
vesting logs or pulpwood and constructed with 
a skeletal frame with no means for attachment 
of a solid bed, body, or container, and with an 
arrangement of air control lines and reservoirs 
designed to minimize damage in off-road opera- 
tions, need not meet the requirements relating to 
wheel lockup, but must nevertheless meet the re- 
quirements of staying within the 12-foot lane. 

S5.3.3 Brake actuation time. With an initial 
service reservoir system air pressure of 100 psi, 
the air pressure in each brake chamber shall, 
when measured from the first movement of the 
service brake control, reach 60 psi in not more 
than 0.45 seconds in the case of trucks and buses, 
0.35 seconds in the case of trailer converter dol- 
lies, and 0.30 seconds in the case of trailers other 
than trailer converter dollies. A vehicle designed 
to tow a vehicle equipped with air brakes shall 
be capable of meeting the above actuation time 
requirement with a 50-cubic-inch test reservoir 
connected to the control line coupling. A trailer, 
including a trailer converter dolly, shall meet the 
above actuation time requirement with its brake 
system connected to the test rig shown in 
Figure 1. 



PART 571; S 121-4 



FIGURE 1 
TRAILER TEST RIG 



relative to brake chamber air pressure shall have 
values not less than those shown in Column 1 
of Table III. Retardation force shall be deter- 
mined as follows: 




TRACTOR PROTECTION VALVE 

(OPTIONAL I 

SUPPLY COUPLING - 

CP, 
CONTROL COUPLING 



SERVICE BRAKE PEDAL 



S5.3.4 Brake release time. With an initial 
service brake chamber air pressure of 95 psi, the 
air pressure in each brake chamber shall, when 
measured from the first movement of the service 
brake control, fall to 5 psi in not more than 
0.55 seconds in the case of trucks and buses, and 
fall to 5 psi in not more than 0.65 seconds in the 
case of trailers, including trailer converter dollies. 
A vehicle designed to tow another vehicle 
equipped with air brakes shall be capable of 
meeting the above release time requirement with 
a 50-cubic-inch test reservoir connected to the 
control line coupling. A trailer, including a 
trailer converter dolly, shall meet the above re- 
lease time requirements with its brake system 
connected to the test rig shown in Figure 1. 

S5.4 Service brake system— dynamometer tests. 

When tested without prior road testing, under 
the conditions of S6.2, each brake assembly shall 
meet the requirements of S5.4.1, S5.4.2, and 
S5.4.3 when tested in sequence and without ad- 
justments other than those specified in the stand- 
ard. For purposes of the requirements of S5.4.2 
and S5.4.3, an average deceleration rate is the 
change in velocity divided by the deceleration 
time measured from the onset of deceleration. 

S5.4.1 Brake retardation force. The sum of 

the retardation forces exerted by the brakes on 
each vehicle designed to be towed by another 
vehicle equipped with air brakes shall be such 
that the quotient 

sum of the brake retardation forces 

sum of GAWRs 







TABLE 


III 




BRAKE 


RETARDATION FORCE 


BRAKE RETARDATION 




BRAKE CHAMBER 


FORCE 


GAWR 




PRESSURE, p.s.i. 


Column 1 








Column 2 


0.05 








20 


0.12 








30 


0.18 








40 


0.25 








50 


0.31 








60 


0.37 








70 


0.41 








80 



S5.4.1.1 After burnishing the brake pursuant 
to S6.2.6, retain the brake assembly on the inertia 
dynamometer. With an initial brake temperature 
between 125°F and 200°F, conduct a stop from 
50 mph, maintaining brake chamber air pressure 
at a constant 20 psi. Measure the average torque 
exerted by the brake from the time the specified 
air pressure is reached until the brake stops and 
divide by the static loaded tire radius specified 
by the tire manufacturer to determine the re- 
tardation force. Repeat the procedure six times, 
increasing the brake chamber air pressure by 10. 
After each stop, rotate the brake drum or disc 
until the temperature of the brake falls to be- 
tween 125°F. and 200°F. 

S5.4.2 Brake power. When mounted on an 
inertia dynamometer, each brake shall be capable 
of making 10 consecutive decelerations at an 
average rate of 9 fpsps from 50 mph to 15 mph, 
at equal intervals of 72 seconds, and shall be 
capable of declerating to a stop from 20 mph at 
an average deceleration rate of 14 fpsps one 
minute after the 10th aceleration. The series of 
decelerations shall be conducted as follows: 

S5.4.2.1 With an initial brake temperature 
between 150°F and 200°F for the first brake 
application, and the drum or disc rotating at a 
speed equivalent to 50 mph, apply the brake and 



PART 571; S 121-5 



decelerate at an average deceleration rate of 9 
fpsps to 15 mph. Upon reaching 15 mph, accel- 
erate to 50 mph and apply the brake for a second 
time 72 seconds after the start of the first appli- 
cation. Repeat the cycle until 10 decelerations 
have been made. The service line air pressure 
-Shall not exceed 100 psi during any deceleration. 

S5.4.2.2 One minute after the end of the last 
deceleration required by S5.4.2.1 and with the 
drum or disc rotating at a speed of 20 mph, de- 
celerate to a stop at an average deceleration rate 
of 14 fpsps. The service brake line air pressure 
shall not exceed 108 psi. 

S5.4.3 Brake recovery. Starting 2 minutes 
after completing the tests required by S5.4.2, the 
brake of a vehicle other than either front axle 
brake of a truck-tractor shall be capable of mak- 
ing 20 consecutive stops from 30 mph at an aver- 
age deceleration rate of 12 ft/s/s, at equal 
intervals of 1 minute measured from the start of 
each brake application. The service line air 
pressure needed to attain a rate of 12 ft/s/s shall 
be not more than 75 lb. /in. 2, and not less than 
20 Ib./in.^ for a brake not subject to the control 
of an antilock system, or 12 Ib./in.^ for a brake 
subject to the control of an antilock system. 

55.5 Antilock system. 

55.5.1 Antilock system failure. On a vehicle 
equipped with an antilock system, electrical fail- 
ure of any part of the antilock system shall not 
increase the actuation and release times of the 
service brakes. 

55.5.2 Antilock system power— trailers. On a 

trailer equipped with an antilock system that re- 
quires electrical power for operation, the power 
shall be obtained from the stop lamp circuit. 
Additional circuits may also be used to obtain 
redundant sources of electrical power. 

55.6 Parking brake system. Each vehicle 
other than a trailer converter dolly shall have a 
parking brake system that under the conditions 
of S6.1 meets the requirements of S5.6.1 or 
S5.6.2, at the manufacturer's option, and the re- 
quirements of S5.6.3 and S5.6.4. However, a 
trailer that is designed to transport bulk agricul- 
tural commodities in off-road harvesting sites and 
to a processing plant or storage location, as evi- 



denced by skeletal construction that accommo- 
dates harvest containers, a maximum length of 28 ' 
feet, and an arrangement of air control lines and 
reservoirs that minimizes damage in field opera- ; 
tions, shall meet the requirements of this section 
or, at the option of the manufacturer, the require- 
ments of § 393.43 of the title. 

S5.6.1 Static retardation force. With all other 
brakes rendered inoperative, during a static 
drawbar pull in a forward or rearward direction, 
the static retardation force produced by the ap- 
plication of the parking brakes shall be: 

(a) In the case of a vehicle other than a truck- 
tractor that is equipped with more than two 
axles, such that the quotient 

static retardation force 



GAWR 

is not less than 0.28 for any axle other than a 
steerable front axle; and 

(b) In the case of a truck-tractor that is 
equipped with more than two axles, such that 
the quotient 

static retardation force 



GVWR 
is not less than 0.14. 

55.6.2 Grade fiolding. With all parking 
brakes applied, the vehicle shall remain sta- 
tionary facing uphill and facing downhill on a 
smooth, dry portland cement concrete roadway 
with a 20% grade, both (a) when loaded to its 
gross vehicle weight rating, and (b) at its un- 
loaded vehicle weight plus 500 pounds (includ- 
ing driver and instrumentation). 

55.6.3 Application and holding. The parking 
brakes shall be applied by an energy source that 
is not affected by loss of air pressure or brake 
fluid pressure in the service brake system. Once 
applied, the parking brakes shall be held in the 
applied position solely by mechanical means. 

55.6.4 Parking brake control— trucks and buses. 

The parking brake control shall be separate from 
the service brake control. It shall be operable 
by a person seated in the normal driving posi- 
tion. The control shall be identified in a manner 
that specifies the method of control operation. 



PART 571; S 121-6 



The parking brake control shall control the park- 
ing brakes of the vehicle and of any air braked 
vehicle that it is designed to tow. 

S5.7 Emergency brake system— trucks and 
buses. Each vehicle shall be equipped with an 
emergency brake system which, under the con- 
ditions of S6.1, conforms to the requirements of 
S5.7.1 through S5.7.3. The emergency brake 
system may be a part of the service brake system 
or incorporate portions of the service brake and 
parking brake systems. 

S5.7.1 Emergency brake system performance. 

When stopped six times for each combination 
of weight and speed specified in S5.3.1.1 on a 
road surface with a skid number of 75, with a 
single failure in the service brake system of a 
part designed to contain compressed air or brake 
fluid (except failure of a common valve, mani- 
fold brake fluid housing, or brake chamber hous- 
ing), the vehicle shall stop at least once in not 
more than the distance specified in Column 3 of 
Table II, measured from the point at which 
movement of the service brake control begins, 
without any part of the vehicle leaving the road- 
way, except that a truck-tractor tested at its un- 
loaded vehicle weight plus 500 pounds shall stop 
at least once in not more than the distance 
specified in Column 4 of Table II. 

55.7.1.1 Automatic application. The parking 
brakes shall be automatically applied and the 
supply line to any towed vehicle vented to at- 
mospheric pressure when the air pressure in all 
service reservoirs is less than the automatic ap- 
plication pressure level. The automatic applica- 
tion pressure level shall be between 20 and 45 
p.s.i. 

55.7.1.2 Automatic braking performance. With 

the parking brake automatically applied, a ve- 
hicle shall either be capable of meeting the re- 
quirements of S5.7.2.3, with distances measured 
from the point of automatic application, or shall 
have a static retardation force quotient not 
greater than 0.40 for any axle, determined in 
accordance with S5.6.1. 

55.7.1.3 Release after automatic application. 

After automatic application, the parking brakes 
shall be releasable at least once by means of a 
parking control. The parking brakes shall be 



releasable only if they can be automatically re- 
applied and exert the force required by S5.6 
immediately after release. 

S5.7.1.4 Manual operation. The parking 
brakes shall be manually operable and releasable 
when the air pressure in the service reservoir 
system is sufficient to keep the parking brakes 
from automatically applying. 

S5.7.2 Emergency brake system operation. 

The emergency brake system shall be applied and 
released, and be capable of modulation, by means 
of the service brake control. 

55.7.2.1 Emergency braking control. The 

emergency braking system shall be controlled by 
the service brake control or the parking brake 
control. The control for the emergency braking 
system shall control the brakes on any towed 
vehicle equipped with air brakes. 

55.7.2.2 Emergency braking system failure. 

In the event of a failure of a valve, manifold, 
brake fluid housing, or brake chamber housing 
that is common to the service brake and emer- 
gency braking systems, loss of air shall not cause 
the parking brake to be inoperable. 

55.7.2.3 Emergency braking stopping distance. 

Except as specified in S5.7.2.3.1 and S5.7.2.3.2, 
when stopped six times for each combination of 
weight and speed specified in S5.3.1.1 on a road 
surface with a skid number of 75, with a single 
failure in the service brake system of a part de- 
signed to contain compressed air or brake fluid 
(except failure of a common valve, manifold, 
brake fluid housing, or brake chamber housing), 
the vehicle shall stop at least once in not more 
than the distance specified in column 3 of Table 
II, measured from the point at which movement 
of the brake control begins, without any part of 
the vehicle leaving the roadway, except that a 
truck-tractor tested at its unloaded vehicle weight 
plus 500 pounds shall stop at least once in not 
more than the distance specified in Column 4 of 
Table II. 

S5.7.2.3.1 A truck manufactured before Sep- 
tember 1, 1976, that has a front steerable non- 
driving axle with a GAWR of 16.000 pounds or 
more, or a front steerable drive axle with a 
GAWR of less than 18,000 pounds, and a truck 



PART 571; S 121-7 



manufactured before September 1, 1975, that has 
a front steerable drive axle of any GAWR, must 
stop in accordance with S5.7.2.3 without any 
part of the vehicle leaving the roadway, but need 
not stop in the distances specified. 

S5.7.2.3.2 When stopped in accordance with 
S5.7.2.3, a truck or bus manufactured before 
September 1, 1975, other than a truck described 
in S5.7.2.3.1, shall stop at least once for each 
speed and weight condition on a surface with a 
skid number of 75 in not more than the distance 
specified in Table Ila instead of meeting the stop- 
ping distances specified in Table II for stops on 
a surface with a skid number of 75. 

S5.7.3 Towing vehicle emergency brake re- 
quirements. In addition to meeting the other 
requirements of 85. 7, a vehicle designed to tow 
another vehicle equipped with air brakes shall— 

(a) In the case of a truck-tractor in the un- 
loaded condition and a single unit truck which 
is capable of towing an air-brake equipped ve- 
hicle and is loaded to gross vehicle weight rating, 
be capable of meeting the requirements of S5.7.1 
by operation of the service brake control only, 
with the trailer air supply line and air control 
line from the towing vehicle vented to the at- 
mosphere in accordance with S6.1.14; 

(b) In the case of a truck-tractor loaded to 
gross vehicle weight rating, be capable of meet- 
ing S5.7.1 by operation of the service brake con- 
trol only, with the air control line from the 
towing vehicle vented to the atmosphere in ac- 
cordance with S6.1.14; and 

(c) Be capable of modulating the air in the 
supply or control line to the trailer by means of 
the service brake control with a single failure in 
the towing vehicle service brake system as speci- 
fied in S5.7.1. 

S5.8 Emergency braking capability— trailers. 

Each trailer other than a trailer converter dolly 
shall have a parking brake system that conforms 
to S5.6 and that applies with the force specified 
in S5.6.1 or 85. 6. 2 when the air pressure in the 
supply line is at atmospheric pressure. A trailer 
converter dolly shall have, at the manufacturer's 
option, (a) a parking brake system that conforms 
to S5.6 and that applies with the force specified 
in S5.6.1 or 85.6.2 when the air pressure in the 



supply line is at atmospheric pressure, or (b) an 
emergency system that automatically controls the 
service brakes when the serivce reservoir is at 
any pressure above 20 Ib./in.^ and the supply line ,1 
is at atmospheric pressure. However, a trailer 11 
that is designed to transport bulk agricultural 
commodities in off-road harvesting sites and to a 
processing plant or storage location, as evidenced i 
by skeletal construction that accommodates har- 1 
vest containers, a maximum length of 28 feet, and ' 
an arrangement of air control lines and reservoirs 
that minimizes damage in field operations, shall 
meet the requirements of this section or, at the ! 
option of the manufacturer, the requirements of 1 
§ 393.43 of this title. 

S6 Conditions. The requirements of 85 shall 
' be met under the following conditions. Except 
as otherwise specified, where a range of condi- 
tions is specified, the vehicle must be capable of 
meeting the requirements at all points within i 
the range. 

S6.1 Road test conditions. 

56.1.1 Except as otherwise specified, the ve- 
hicle is loaded to its gross vehicle weight rating, 
distributed proportionally to its gross axle weight 
ratings. 

56.1.2 The inflation pressure is as specified 
by the vehicle manufacturer for the gross vehicle 
weight rating. 

56.1.3 Unless otherwise specified, the trans- 
mission selector control is in neutral or the clutch 
is disengaged during all decelerations and during 
static parking brake tests. 

56.1.4 All vehicle openings (doors, windows, 
hood, trunk, cargo doors, etc.) are in a closed 
position except as required for instrumentation 
purposes. 

56.1.5 The ambient temperature is between 
32°F and 100°F. 

56.1.6 The wind velocity is zero. 

56.1.7 Unless otherwise specified, stopping 
tests are conducted on a 122-foot wide, level, 
straight roadway having a skid number in the 
range of 71 to 81, inclusive, chosen at the option 
of the manufacturer. The vehicle is aligned in 



PART 571; 8 121-8 



the center of the roadway at the beginning of 
the stop. 

S6.1.8 The brakes are burnished before testing 
in accordance with S6. 1.8.1. However, for ve- 
hicles with parking brake systems not utihzing 
the service brake friction elements, burnish the 
friction elements of such systems prior to the 
parking brake test according to the manufactur- 
er's recommendations. 

S6.1.8.1 With the transmission in the highest 
gear appropriate for the series given in Table 
IV make 500 brake applications at a deceleration 
rate of 10 ft/s/s, or at the vehicle's maximum 
deceleration rate, if not less than 10 ft/s/s, in the 
sequence specified in Table IV. After each brake 
application, accelerate to the speed specified 

Table IV 

Snub conditions 
Series Snubs (highest speed specified) 



1 


175 


40 to 20 mph. 


2 


25 


45 to 20 mph. 


3 


25 


50 to 20 mph. 


4 


25 


55 to 20 mph. 


5 


250 


60 to 20 mph. 



and maintain that speed until making the next 
brake application at a point 1 mile from the 
initial point of the previous brake application. 
If a vehicle cannot attain the specified speed in 
1 mile, continue to accelerate until the specified 
speed is reached or until the vehicle has traveled 
1.5 miles from the initial point of the previous 
brake application. If during any of the brake 
applications specified in Table IV, the hottest 
brake raches 500° F, make the remainder of 
the 500 applications from that snub condition 
except that a higher or lower snub condition 
shall be used as necessary to maintain an after- 
stop temperature of 500° F±50° F. Any auto- 
matic pressure limiting valve is in use to limit 
pressure as designed, except that any automatic 
front axle pressure limiting valve is bypassed if 
the temperature of the hottest brake on a rear 
axle exceeds the temperature of the hottest brake 
on a front axle by more than 125° F. A bypassed 
valve is reconnected if the temperature of the 
hottest brake on a front axle exceeds the tem- 
perature of the hottest brake on a rear axle by 



100° F. After burnishing, adjust the brakes as 
recommended by the vehicle manufacturer. 

56.1.9 Static parking brake tests for a semi- 
trailer are conducted with the front end sup- 
ported by an unbraked dolly. The weight of 
the dolly is included as part of the trailer load. 

56.1.10 In a test other than a static parking 
brake test, truck-tractor is tested at its gross 
vehicle weight rating by coupling it to a flatbed 
semitrailer (hereafter, control trailer) as speci- 
fied in S6.1.10.1 to S6.1.10.7. 

56.1.10.1 The control trailer conforms to this 
standard. 

56.1.10.2 The center of gravity of the loaded 
control trailer is on the trailer's longitudinal 
centerline at a height of 66 ±3 in. above the 
ground. 

56.1.10.3 For a truck-tractor with a rear axle 
gross axle weight rating of 26,000 lb or less, 
the control trailer has a single axle with a gross 
axle weight rating of 18,000 lb and a length, 
measured from the transverse centerline of the 
axle to the centerline of the kingpin, of 258 ±6 in. 

56.1.10.4 For a truck-tractor with a total rear 
axle gross axle weight rating of more than 26,000 
lb the control trailer has a tandem axle with a 
combined gross axle weight rating of 32,000 lb 
and a length, measured from the transverse cen- 
terline between the axles to the centerline of the 
kingpin, of 390 + 6 in. 

56.1.10.5 The control trailer is loaded so that 
its axle is loaded to its gross axle weight rating 
and the tractor is loaded to its gross vehicle 
weight rating, with the tractor's fifth wheel ad- 
justed so that the load on each axle measured 
at the tire-ground interface is most nearly pro- 
portional to the axles' respective gross axle 
weight ratings. 

56.1.10.6 Test equipment specification. The 

control trailer's service brakes are capable of 
stopping the combination from the maximum, 
speed at which the tractor is tested, under the 
conditions of S6.1, without assistance from the 
tractor brakes, in the distance found by multi- 
plying the value 68, 90, 115, 143, 174, 208, or 245 
(corresponding to a speed of 30, 35, 40, 45, 50, 



PART 571; S 121-9 



55, or 60 mph as appropriate for the truck- 
tractor tested) by the ratio: 

weight on all axles of combination 

weight on trailer axles 

with the tractor's fifth wheel adjusted as speci- 
fied in S6. 1.10.5, the trailer service reservoirs 
pressurized to 100 Ib./in.^, and the trailer loaded 
so that its axle is at gross axle weight rating 
and its kingpin is at empty vehicle weight. The 
stopping distance is measured from the point at 
which movement of the valve controlling the 
trailer brakes begins. The service brake cham- 
bers on the trailer reach 60 Ib./in.^ in not less 
than 0.20 second and not more than 0.30 second, 
measured from the instant at which movement 
of the valve controlling the trailer brakes begins. 

S6.1.10.7 Test equipment specification. The 

control trailer's emergency brakes are capable of 
stopping the combination under the conditions 
of S6.1 from the maximum speed at which the 
tractor is tested, without assistance from the 
tractor's brakes, in the distance found by multi- 
plying the emergency brake stopping distance in 
column 3 of Table II by the ratio: 

weight on all axles of combination 

weight on trailer axles 

with the combination loaded in accordance with 
S6. 1.10.5. Stopping distance is measured from 
the point at which movement of the valve con- 
trolling the trailer brakes begins. In the case of 
control trailers that utilize parking brakes for 
emergency stopping capability, the pressure in 
the trailer's spring parking brake chambers falls 
from 95 Ib./in.^ to 5 Ib./in.^ in not less than 0.50 
second and not more than 0.60 second, measured 
from the instant at which movement of the valve 
controlling the trailer's spring parking brakes 
begins. 

S6.1.11 Special drive conditions. A vehicle 
equipped with an interlocking axle system of a 
front wheel drive system that is engaged and 
disengaged by the driver is tested with the sys- 
tem disengaged. 

S6.1.1.12 Lif table axles. A vehicle with a lift- 
able axle is tested at gross vehicle weight rating 
with the liftable axle down and at unloaded ve- 
hicle weight with the liftable axle up. 



[S6.1.13 The trailer test rig shown in Figure 1 
is capable of increasing the pressure in a 50 cubic 
inch reservoir from atmospheric to 60 Ib./in.^ in 
0.06 second, measured from the first movement 
of the service brake control to apply service 
brake pressure and of releasing pressure in such 
a reservoir from 95 to 5 Ib./in.^ in 0.22 second 
measured from the first movement of the service 
brake control to release service brake pressure. 

56.1.14 In testing the emergency braking 
system of towing vehicles under S5. 7.3(a) and 
S5. 7.3(b) the hose(s) is vented to the atmos- 
phere at any time not less than 1 second and 
not more than 1 minute before the emergency 
stop begins, while the vehicle is moving at the 
speed from which the stop is to be made and any 
manual control for the towing vehicle protection 
system is in the position to supply air and brake 
control signals to the vehicle being towed. No 
brake application is made from the time the 
line(s) is vented until the emergency stop begins 
and no manual operation of the parking brake 
system or towing vehicle protection system occurs 
from the time the line(s) is vented until the 
stop is completed. 

56.1.15 Initial brake temperature. The tem- 
perature of each brake is measured by a single 
plug-type thermocouple installed in the center 
of the lining surface of the most heavily loaded 
shoe or pad as shown in Figure 2. The thermo- 
couple is outside any center groove. With the 
exception of conditions specified for burnishing 
brakes in paragraph S6.1.8, repetitive test runs 
are separated by an interval of time sufficient 
to reach any initial brake temperature in the 
range of 150°F to 200°F. If the initial brake 
temperature for the first stop in a test procedure 
has not been reached, heat the brakes to the ini- 
tial brake temperature by making not more than 
10 snubs from not more than 40 to 10 mph at a 
deceleration not greater than 10 fpsps. 

S6.2 Dynamometer test conditions. 

56.2.1 The dynamometer inertia for each wheel 
is equivalent to the load on the wheel with the 
axle loaded to its gross axle weight rating. 

56.2.2 The ambient temperature is between 
75°F and 100°F. 



PART 571; S 121-10 



56.2.3 Air at ambient temperature is directed 
uniformly and continuously over the brake drum 
or disc at a velocity of 2,200 feet per minute. 

56.2.4 The temperature of each brake is 
measured by a single plus type thermocouple 
installed in the center of the lining surface of 
the most heavily loaded shoe or pad as shown in 
Figure II. The thermocouple is outside any 
center groove. 

56.2.5 The rate of brake drum or disc rota- 
tion on a dynamometer corresponding to the rate 
of rotation on a vehicle at a given speed is cal- 
culated by assuming a tire radius equal to the 
static loaded radius specified by the tire manu- 
facturer. 

56.2.6 Brakes are burnished before testing 
as follows: Place the brake assembly on an in- 
ertia dynamometer and adjust the brake as rec- 
ommended by the brake manufacturer. Make 
200 stops from 40 mph at a deceleration of 10 
fpsps, with an initial brake temperature on each 
stop of not less than 315 °F and not more than 
385 °F. Make 200 additional stops from 40 mph 
at a deceleration of 10 fpsps with an initial 
brake temperature on each stop of not less than 
450 °F and not more than 550 °F. After burnish- 
ing, the brakes are adjusted as recommended by 
the brake manufacturer. 

56.2.7 The brake temperature is increased to 
a specified level by conducting one or more stops 



FIGURE 2 
THERMOCOUPLE INSTALLATION 




'OO MAI Oe^TH 



from 40 mph at a deceleration of 10 fpsps. The 
brake temperature is decreased to a specified 
level by rotating the drum or disc at a constant 
30 mph. 

36 F.R. 3817 
February 27, 1971 



PART 571; S 121-11 



EHactlve: Scpttmber 1, 1973 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 122 
Motorcycle Brake Systems 



This notice amends Part 571 of Title 49, Code 
of Federal Regulations, to add a new Motor 
Vehicle Safety Standard No. 122 (49 CFR § 571.- 
122) that establishes performance requirements 
for motorcycle brake systems. A notice of pro- 
posed rulemaking on this subject was published 
on March 24, 1971 (36 F.R. 5516). 

The safety afforded by a motorcycle's brak- 
ing system is determined by several factors, in- 
cluding stopping distance, linear stability whib 
stopping, fade resistance, and fade recovery. A 
safe system should have features that both guard 
against malfunction and stop the vehicle should 
a malfunction occur in the normal service sys- 
tem. Standard No. 122 covers each of these 
aspects of brake safety, establishing equipment 
and performance requirements appropriate for 
two-wheeled and three-wheeled motorcycles. 
These requirements do not differ greatly from 
the proposals, and comments received in response 
to the notice have been considered in promulgat- 
ing the rule. 

I. Equipment. Each motorcycle is required 
to have either a split hydraulic service brake 
system or two independently actuated service 
brake systems. The latter system encompasses 
a hydraulic service brake system combined with 
a hand operated parking brake system. Although 
several objections were received to the split 
hydraulic service brake system proposal, the 
NHTSA has determined that partial failure 
braking features are necessary in the event of a 
hydraulic pressure loss in the nomial service 
brake system. If a motorcycle has a hydraulic 
service brake system, it must also have a reservoir 
for each master cylinder, and a master cylinder 
reservoir label advising the proper grade of DOT 
brake fluid. If the service brake system is a 
split hydraulic type, a failure indicator lamp 
is required. 



Additionally, three-wheeled motorcycles must 
be equipped with a friction type parking brake 
with a solely mechanical means to retain engage- 
ment. Some commenters felt that pin or pawl 
type brakes should be permitted. The Admin- 
istration does not know of an impact test ade- 
quate to test the strength of a mechanical lock, 
and pin or pawl type brakes, prone to failure 
upon impact, have been found to be inadequate. 
The NHTSA concurs, however, with comments 
objecting to the proposed parking brake indicator 
lamp, and has determined that the safety bene- 
fits involved are negligible in comparison with 
the expense of providing it. 

II. Performance. Conformity with perform- 
ance requirements will be determined by subject- 
ing motorcycles to a series of road tests. Vehicles 
must demonstrate the effectiveness of their serv- 
ice brake systems by stopping within specified 
distances from 30 mph, 60 mph, 80 mph, and 
from a speed divisible by 5 mph that is 4 mph 
to 8 mph less than the maximum vehicle speed. 

Motorcycles will demonstrate fade resistance 
of their braking systems by making recovery 
stops subsequent to a series of fade stops from 
60 mph. The hand lever force for the final re- 
covery stop must be within plus 20 pounds and 
minus 10 pounds of the baseline check average 
force. This is a modification of the proposed 
"plus 10 pounds or 20 percent, whichever, is less, 
and minus 20 percent," based upon comments 
requesting the substitution of absolute values. 
The same modification is made in the final water 
recovery stop. The maximum speed fade and 
recovery proposal has not been adopted, as two 
and three-wheeled motor vehicles do not have 
the inherent cooling problems that braking sys- 
tems on four-wheeled vehicles experience. Reten- 
tion of the 60 mph stops will ensure that the 
system maintain adequate stopping ability despite 



PART 571; S 122— PRE 1 



Effective: September 1, 1973 

the high temperatures created by prolonged use, 
and may reveal undesirable brake lining char- 
acteristics such as glazing. 

The test sequence has been rearranged so that 
the parking brake system test for three-wheeled 
motorcycles occurs immediately before the water 
recovery test. At this point in the test sequence 
the brakes will have been fully burnished, and 
the test will therefore be more indicative of 
service performance. Parking brake application 
forces have been modified from the proposal, and 
specify a maximum applied force of not more 
than 90 pounds for a foot-operated system and 
55 pounds for a hand-operated system. These 
forces are identical to those specified in S6.10, 
the test condition on brake actuation forces, and 
result in a uniformity of brake actuation forces 
throughout the standard. 

Finally, a motorcycle must demonstrate ac- 
ceptable stopping performance after its brake 
system has been exposed to water. Comments 
expressed dissatisfaction with the proposed test 
procedure, stating that complete immersion of 
the brakes is not indicative of the manner in 
which they become wet in actual service. NHTSA 
agrees that poor braking performance often is 
not attributable to complete immersion, but 
rather to prolonged exposure to a constant spray 
from the road surface. However, there is no 
basis on which to specify a test procedure reflect- 
ing these conditions, and the immersion procedure 
has, therefore, been retained. 

At the end of the test procedure the brake 
system must pass a durability inspection. 

All stops must be made without lockup of any 
wheel. Two-wheeled motorcycles must remain 
within an 8-foot-wide lane during stops (modi- 
fied from the proposed 6-foot-wide lane), and 
three-wheeled ones within a lane equal to vehicle 
width plus five feet. Some commenters asked 
that tests be performed with the clutch engaged. 
However, the effectiveness of a brake system in 
bringing a vehicle to a stop within required 
distances is more accurately judged by requiring 
that stops be made with the clutch disengaged; 
there is less reliance on extraneous factors such 
as use of engine retardation as a braking assist 
and the varying skills of individual drivers when 
shifting downward through gears. 



Regarding test conditions, comments were re- 
ceived that it is unnecessary for both braking 
systems of a two-wheeled motorcycle to be within 
the specified pedal and lever force range simul- 
taneously. The Administration did not concur 
with these comments. The safety of cyclists 
requires not only that motorcycles be capable of 
stopping within specified distances, but also that 
this capability be demonstrated when reasonable 
forces are applied to the brake lever and pedal. 

Several commenters also objected to the "im- 
possibility" of the test condition that "the wind 
velocity is zero." The comment reveals misunder- 
standing of the significance of the test condi- 
tions. A manufacturer may test for compliance 
by running the tests under any wind conditions 
that are adverse to the vehicle; obviously if the 
vehicle meets the requirements under adverse 
wind conditions, it will meet them under no- 
wind conditions. Similarly, the Government will 
prove noncompliance by orienting the test runs 
so that wind conditions are favorable to the 
vehicle. Thus, the condition uniquely allows 
testing under whatever wind conditions are pres- 
ent. It is retained as the most practicable and 
least burdensome test method for all parties. 

Effective date: September 1, 1973. Because of 
the necessity to allow manufacturers sufficient 
production leadtime, it is found for good cause 
shown, that an effective date later than one year 
after issuance is in the public interest. 

In consideration of the foregoing. Title 49, 
Code of Federal Regulations, is amended by add- 
ing § 571.122, Motor Vehicle Safety Standard 
No. 122, Motorcycle Brake System. 

This notice is issued under the authority of 
section 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act of 1966 (15 U.S.C. 
1392, 1407) and the delegation of authority from 
the Secretary of Transportation to the National 
Highway Traffic Safety Administrator, 49 CFR 
1.51. 



Issued on : March 1, 1972. 



Charles H. Hartman 
Acting Administrator 

37 F.R. 5033 
March 9, 1972 



PART 571 ; 8 122— PRE 2 



Effective: January 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 122 

Motorcycle Brake Systems 
(Docket No. 1-3; Notice No. 4) 



This notice responds to petitions for reconsid- 
eration of Motor Vehicle Safety Standard No. 
122 (49 CFR § 571.122), and changes the effective 
date of the standard to January 1, 1974. 

Motor Vehicle Safety Standard No. 122 estab- 
lishing requirements for motorcycle braking 
equipment, stopping distance, brake system fade 
and recovery, and wet brake recovery, effective 
September 1, 1973, was published on March 9, 
1972 (37 F.R. 5033). Thereafter, pursuant to 
49 CFR § 553.35, petitions for reconsideration of 
the rule were filed by Japan Automobile Manu- 
facturers Association, Inc. ("JAMA"), and 
Cushman Motors ("Cushman") through counsel. 
In response to these petitions, the effective date 
of the standard is being changed. The Admin- 
istrator has declined to grant requested relief 
from other requirements of the standard. 

1. Lining inspection requirement. S5.1.5 of 
Standard No. 122 requires a brake system to be 
installed "so that the lining thickness of drum 
brake shoes may be visually inspected, either di- 
rectly or by use of a mirror without removing 
the drums. . . .'" JAMA has petitioned that the 
word "indirectly" be substituted for "by use of a 
mirror" in order to allow use of a device such 
as a wear indicator on the outside of front and 
rear brake panels. The NHTSA considers wear 
indicators to be a "direct" method of visual in- 
spection since the extent of lining wear may be 
determined without removal of the drums. There 
is no need to amend the Standard to allow their 
use, and JAMA's petition is denied. 

2. Brake wetting procedure. The procedure 
for wetting the brakes prior to testing for wet 
brake recovery (S7.10.2) specifies the complete 
immersion of brake assemblies. 



JAMA has petitioned that a water trough be 
substituted, with water depth varying according 
to the cycle's tire rim size, through which the 
cycle would be driven for 2 minutes at a speed 
of 10 m.p.h. JAMA notes that this is similar 
to the procedure NHTSA proposed in Docket 
No. 70-27, Hydraulic Brake Systems, and com- 
mented that the same procedure should apply to 
all motor vehicles. 

The NHTSA has determined that the inherent 
instability of two- and three-wheeled vehicles 
under wet road conditions justifies a different 
test procedure. The difference in configuration 
between motorcycles and four-wheeled vehicles 
is distinct enough that there is no assurance 
motorcycle brakes will be wet, or wet uniformly, 
by the trough method. It is recognized that 
neither m.ethod may represent the way brakes 
become wet under actual road conditions, but 
immersion of brake assemblies has been deter- 
mined to be the more efficiently reproducible 
method of establishing a condition under which 
motorcycle brake system performance may be 
evaluated. The petition is denied. 

3. Stopping distance. JAMA and Cushman 
petitioned for a relaxation of the stopping dis- 
tance requirements of Table I. JAMA recom- 
mended that the stopping distance values in 
Column II (Preburnish effectiveness, partial 
mechanical system) and Column III (Effective- 
ness — total system) up to and including 70 m.p.h. 
be the stopping distances specified in SAE Rec- 
ommended Practice J109a. This would mean an 
increase in range of 39-136 feet for the pre- 
burnish stopping distances, and 1-15 feet for 
total system effectiveness over the values of 
Standard No. 122. JAMA alleges that stopping 
distance is highly dependent upon the rider's 



PART 571; S 122— PRE 3 



EfFacllve: January 1, 1974 

ability to control the brakes, and it requested the 
increased stopping distances to compensate for 
variations in the rider's skill. 

Cushman, whose three-wheeled vehicles have a 
top speed of 38 m.p.h., requests that all stopping 
distances from 30 m.p.h. and 35 m.p.h. be modi- 
fied, alleging that the only way it can meet the 
stopping distances is by redesigning its vehicle. 
Cushman also states that it is unaware of any 
incident where the stopping distances achieved 
by its present vehicle have become a factor in an 
accident, and that accordingly there is no need 
for the stopping distances set forth in Table I, 
as they apply to Cushman, in order to protect 
the public. 

The NHTSA recognizes that its standards on 
braking (the forthcoming amendment to Stand- 
ard No. 105, Hydraulic Brake Systems, Standard 
No. 121, Air Brake Systems, and Standard No. 
122, Motorcycle Brake Systems) impose stringent 
requirements on the manufacturers of all types 
of vehicles, and that, in some instances, redesign 
may be necessary. But because of the ever in- 
creasing numbers of vehicles on urban and inter- 
state roadways, and of passenger-miles traveled, 
the NHTSA considers improved braking systems 
to be the highest priority in its prog'-am of ac- 
cident avoidance. Prompt and accurate braking 
response is deemed especially critical in providing 
a margin by which the vulnerable motorcyclist 
may escape death or serious injury. While the 
fatality rate for all motor vehicle occupants fell 
3.8 per cent in 1970, it rose 18.9 per cent for 
motorcycle riders. Motorcycles account for less 
than 2.3 per cent of total vehicle registrations, 
but they are involved in 3.6 per cent of all fatal 
accidents. Therefore, the necessity that the in- 
dustry achieve the full capability of the present 



state of the art. has been found to outweigh the 
problems caused the individual manufacturers by 
compliance. 

The NHTSA recognizes the effect of rider 
control upon stopping distance in the wording of 
S7. which deems stopping distance requirements 
met if only one of the specified number of stops 
occurs within the maximum allowable stopping 
distances. Comments to Docket No. 1-3 indicate 
that it is clearly reasonable and practicable to 
require motorcycles to meet the stopping distances 
adopted for Standard No. 122. The petitions of 
JAMA and Cushman are denied. 

4. Elective date. JAMA has requested a 4 
month delay in the effective date of Standard 
No. 122 because model changeover time for Japa- 
nese manufacturers extends through autumn to 
the end of the year. It estimates that only 50 
per cent of the industry could be brought into 
compliance by September 1, 1973. In light of the 
design changes that may be necessitated, the Ad- 
ministrator finds this request reasonable and that 
for good cause shown a later effective date is in 
the public interest. The effective date of Stand- 
ard No. 122 is hereby changed to January 1, 1974. 

The notice is issued pursuant to the authority 
of sections 103 and 119 of the National Traffic 
and Motor Vehicle Safety Act of 1966 (15 U.S.C. 
1392, 1407) and the delegation of authority from 
the Secretary of Transportation to the National 
Highway Traffic Safety Administrator, 49 CFR 
1.51. 



Issued on June 9, 1972. 



Douglas W. Toms 
Administrator 

37 F.R. 11973 
June 16, 1972 



PART 571; S 122— PRE 4 



Effective: January 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 122 

Motorcycle Brake Systems 
(Docket No. 1-3; Notice 6) 



This notice amends Motor Vehicle Safety 
Standard No. 122, Motorcycle Brake Systems, 
49 CFR 571.122, to modify the master cylinder 
labeling and the wetting procedure for the water 
recovery test, effective January 1, 1974. 

The amendment is based upon a notice pub- 
lished December 15, 1972, (37 F.R. 26739). The 
NHTSA proposed a change in the wording of 
the master cylinder reservoir label which would 
be identical to that specified in Motor Vehicle 
Safety Standard No. 105a, Hydraulic Brake Sys- 
tems (37 F.R. 17970). In addition, a change in 
the wetting procedure for the water recovery 
test was proposed to require sequential immersion 
of the front and rear brake assemblies in lieu 
of simultaneous immersion. 

The comments recei\ed generally supported the 
proposal. Some minor changes were requested, 
and Standard No. 122 is being amended accord- 
ingly. The reservoir labeling requirements have 
been modified in format in a manner consistent 
with recent amendments to Standard No. 105a 
(38 F.R. 1.3017). The height of the lettering 
has been retained at 3/32 of an inch. In order 
to avoid any misinterpretation, it is the NHTSA's 
intent to have the label completed with DOT 
and the grade of fluid designed for use in the 
system and not a manufacturer's brand name 
and number. If, however, silicone-based or petro- 
leum-based fluids are appropriate for the system 
design specific fluids may be designated until a 
DOT grade and performance requirements have 
been specified. A contrast in color will be re- 
quired only of printed labels. For this pur- 
pose, it has been decided that raised or lowered 



letters will provide a suflScient degree of legi- 
bility. 

Finally, based on a comment made by the 
Japan Automobile Manufacturers Association, 
Inc. (JAMA), the wetting procedure for the 
water recovery test has been changed to extend 
the maximum testing time from 5 minutes to 
7 minutes. JAMA stated that immersion of the 
rear brake ' first would still create engine stall 
problems if the water were allowed to enter the 
engine through the muffler (s) during the front 
brake assembly immersion period. The NHTSA 
feels strongly that the front brake should be 
immersed last due to potential instabilies created 
by a "grabbing" front brake. The extra time 
which has been allotted should be sufficient for 
manufacturers to provide protection for the ex- 
haust system, thereby alleviating the problem of 
engine stall, and providing a measure of relief 
for those who considered the 5-minute period as 
excessiv-ely short. 

In consideration of the foregoing, 49 CFR 
§571.122, Motor Vehicle Safety Standard No. 
122, is amended. . . . 

E-ffective date: January 1, 1974. 

(Sees. 103, 112, 119 Pub. L. 89-563, 80 Stat. 
718, 15 U.S.C. 1392, 1401, 1407; delegation of 
authority at 38 F.R. 12147) 

Issued on May 30, 1973. 

James E. Wilson 
Associate Administrator 
Traffic Safety Programs 

38 F.R. 14753 
June 5, 1973 



PART 571; S 122— PRE 5-6 



Effective: October 14, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 122 

(Docket No. 74-16; Notice 2) 



This notice amends 49 CFR 571.108, 571.122, 
and 571.123, Motor Vehicle Safety Standards 
Nos. 108, 122. and 123, to modify current re- 
quirements that apply to motor-driven cycles. 

Interested persons have been afi'orded an op- 
portunity to participate in tJie making of tJie 
amendment l)y a notice of pro[)osed rulemaking 
publislied on April 12, 1974 (39 F.R. 13287) and 
due consideration has been given to all comments 
received in response to the notice, insofar as they 
relate to matters within its scope. 

The prior notice responded to petitions by 
Cycles Peugeot, Ateliers de la Motobecane. and 
S.I.X.F.A.C., manufacturers, and Bermuda Bikes, 
Inc., and Robert F. Smith, retail dealers. The 
notice proposed that a motor-driven cycle whose 
speed attainable in 1 mile is 30 mph or less need 
not be equipped with turn signal lamias, and may 
be equipped with a stop lamp with one-half the 
photometric output otherwise required. Braking 
fade and recovery requirements also would not 
apply to these low-speed vehicles. Maximum 
stopping distance values for the various tests 
should l)e added for test speeds of 25, 20, and 15 
mph. Finally, a braking control on the left 
handlebar would be a permissible alternative to 
the required right foot braking control. 

The comments received addressed Iwth areas 
of ]>erformance covered in the proposal, and 
areas where no standards currently exist, such 
as motors, transmissions, pedals, and a request 
for exemption from Standard No. 119, Tires for 
Vehiehft Other Than PoHseTiger Cars. As these 
latter comments cover matters beyond the scope 
of the proposal, this notice does not discu.ss them. 
The agency, however, has been formally peti- 
tioned for rulemaking covering transmissions 
and Standard No. 119, and will respond to the 
petitioners in the near future. 

The decision by NHTSA not to establish a 
separate category of vehicle was objected to by 



some commenrers. In support of their request, 
they argued that the majority of motor-driven 
cycles have engines producing only 1.5 to 2 horse- 
power, and consequent low maximum speede, 
reducing the need for forward lighting that is 
currently required of these vehicles. Petitioners 
submitted no data justifying their request. The 
XHTSA, liowever, intends to study tiie matter 
of forward lighting for low-powered two- 
wiieeled \ehicles through a re.search contract 
with the University of Michigan. When the 
contract is completed the agency will then decide 
wliether further rulemaking is warranted. 

The proposal distinguished motor-driven 
cycles on the basis of maximum speed attainable 
in 1 mile, ratiier than on horsepower, and the 
value selected, 30 mph, fell within the maximum 
(40 mph) and minimum (20 mph) suggested by 
commenters. The NHTSA has concluded there- 
fore that the distinction should be adopted as 
proposed. 

Some manufacturers requested restrictive con- 
trols on power plant output, apparently in fear 
that the engine of a vehicle with a top speed of 
30 mph or less could be modified to exceed that 
speed, and therefore cause the vehicle to no 
longer comi)ly with the Federal standards. This 
agency lias not found that course of action to be 
practicable. The various ways to modify a ve- 
hicle after purchase cannot be anticipated or 
prevented at tlie manufacturer level. On the 
other liand, the great majority of consumers use 
tlieir vehicles in tlie form in which they were 
purchased. The motor-driven cycle category it- 
self contains a limitation of 5 horsepower, which 
will be applicable to the special lighting modi- 
fications. In the NHTSAs judgment, modifica- 
tions bj' consumers and the consequent equipment 
requirements should continue to be regulated at 
the State level. 



PART 571; S 122— PRE 7 



Effective: October 14, 1974 



The fact that the agency took no action to 
propose a reduction in existing headhxmp re- 
quirements for motor-driven cycles was criticized 
by several manufacturers as unduly restrictive 
because of the low speed and power output of 
their vehicles. No justification has been shown 
for such a cliange. Motor-driven cycles therefore 
must have sufficient generating and/or battery 
capacity to meet the headlamp requirements. 

There was no substantive objection to the ac- 
tual proposals for omission of turn signals, re- 
duced stop lamp photometries, relief from brake 
fade requirements, inclusion of maximum allovr- 
able stopping distances for low speeds, and rear 
brake control placement. Accordingly, the 
standards are being amended in the manner 
proposed. 

Standard No. 122 is also being amended to 
delete the final effectiveness test (S5.5) for those 
motor-driven cycles excused from the fade and 
recovery requirements. The purpose of the final 
effectiveness test is to check the stopping ability 
of the vehicle after the fade and recovery tests. 
Since this requirement has been eliminated for 
motor-driven cycles of low top-speed, the final 
effectiveness test is redundant, and an unneces- 



sary duplication of the second effectiveness test. 
No safety purpose is served by its retention. 
Language is also added to the fade and recovery 
and final effectiveness test procedures (S7.6, 
S7.7, and S7.8), making it clear that they do not 
apply to motor-driven cycles whose speed attain- 
able in 1 mile is 30 mph or less. 

In consideration of the foregoing, 49 CFR 
Part .571 is amended .... 

Ineffective date: October 14, 1974. As the 
amendments allow new options for compliance, 
relieve restrictions, and impose no additional 
burdens on regulated persons, it is found for 
good cause shown tha^. an effective date earlier 
than 180 days after issuance of the amendments 
is in the public interest. 

(Sec. 10.3, 119, Pub. L. 89-563, 80 Stat. 718, 
15 U.S.C. 1392, 1407; delegation of authority at 
49 CFR 1.51.) 

Issued on September 6, 1974. 

James B. Gregory 
Administrator 

39 f.R. 32914 
September 12, 1974 



PART 571 ; S 122— PRE 8 



Effective: December 10, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 122 



Motorcycle Brake Systems 



This notice corrects an error in paragraph 
S7.8.1 of 49 CFR 571.122, Motor Vehicle Safety 
Standard No. 122, Motorcycle Brake Systems. 

On March 24, 1971 NHTSA proposed (36 FR 
5516) as part of its anticipated motorcycle brak- 
ing standard, that the final effectiveness test "re- 
peat S7.6 including S7.3.1". Proposed S7.6 was 
the service brake system second effectiveness test. 
Wlien Standard No. 122 was issued on March 9, 
1972 (37 F.R. 5033) the proposal was adopted, 
in S7.8.1, that the final effectiveness test "Repeat 
S7.6 including S7.3.1". However, in the develop- 
ment of the final rule the test sequence was re- 
arranged and the second effectiveness test had 
become S7.5. Through oversight, a corresponding 
change was not made in the final effectiveness 
test provisions. Accordingly the change is being 
made by this notice. 



In consideration of the foregoing, paragraph 
S7.8.1 of 49 CFR § 571.122, Motor Vehicle Safety 
Standard No. 122 is revised to read "S7.8.1 Serv- 
ice brake system. Repeat S7.5 including S7.3.1". 

Ejfective date: December 10, 1974. Because the 
notice corrects an error and creates no additional 
burden upon any person, it is found for good 
cause shown that an immediate effective date is 
in the public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718, 15 
U.S.C. 1392, 1407 ; delegation of authority at 49 
CFR 1.51) 

Issued on December 4, 1974. 

James B. Gregory 
Administrator 

39 F.R. 43075 
December 10, 1974 



PART 571; S 122— PRE 9-10 



Effective: June 14, 1976 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 122 

Motorcycle Brake Systems 
(Docket No. 75-27; Notice 4) 



This notice amends Standard No. 106-75, 
Hydraulic Brake Systems^ and Standard No. 122, 
Motorcycle Brake Systems, to modify the means 
for establishing the frictional resistance of the 
surface on which stopping distance tests are con- 
ducted. A similar amendment is made to Part 
575, Consumer Information, of Title 49 of the 
Code of Federal Regulations. 

The National Highway Traffic Safety Admin- 
istration (NHTSA) proposed the change in 
Standard No. 105-75 (49 CFR 571.105-75), 
Standard No. 121, Air Brake Systems (49 CFE 
571.121), Standard No. 122 (49 CFR 571.122), 
and the Consumer Information Regulations (49 
CFR 575.101) in response to a petition from 
British-Leyland Motors Limited (40 FR 45200, 
October 1, 1975). The existing test procedure in 
these regulations has specified use of the Ameri- 
can Society for Testing and Materials (ASTM) 
E-274-65T procedure, using an ASTM E249 tire 
that is no longer manufactured. 

Responses were received on the proposed ASTM 
change from White Motor Corporation (Wliite), 
Mack Trucks, Inc. (Mack), Freightliner Corpor- 
ation (Freightliner), Ford Motor Company 
(Ford), General Motors Corporation (GM), 
Chrysler Corporation (Chrysler), American 
Motors Corporation (AMC), and International 
Harvester (IH). The National Motor Vehicle 
Safety Advisory Council made no comment on 
the proposal. 

Most conunenters supported use of the new 
test procedure and tire, although they differed in 
recommendations for correlating the reading 
produced under the new procedure with that pro- 
duced under the old procedure. Manufacturers 
are presently certifying compliance to brake 
standards on test surfaces with a satisfactory 
reading under the old procedure, and they should 



be able to continue testing and certifying com- 
pliance on the same surface without anj' increase 
in the severity of the tests. To accomplish this 
transition, the correlation in readings between 
the procedures has been determined, and the dif- 
ference is reflected in a change of the dry surface 
value from "skid number" 75 to "skid number" 
81. 

Freightliner urged postponement of any action 
until it could be supported by "adequate and 
statistically reliable test data." AMC also recom- 
mended that the NHTSA do nothing "until the 
industry has had sufficient time to evaluate and 
verify the performance of the ASTM E501 test 
tire on all types of surfaces." 

The change in procedure is prompted by the 
ASTM decision to utilize a new tire in ascertain- 
ing the frictional coefficient of test surfaces. As 
a result the old tire is no longer manufactured 
and only the new tire is available for skid num- 
ber measurement. Manufacturers have conducted 
comparative tests with the new tire to determine 
the correlation between the readings given by the 
two tires. Neither Freightliner nor AMC sub- 
mitted data showing that the agency's proposal 
to adjust the dry surface skid number upwards 
is unjustified. Only Mack submitted data and it 
supported the NHTSA and Federal Highway 
Administration test data that have been placed 
in the docket. General Motors considered the 
agency's proposed upward adjustment to be the 
maximum desirable based on its data. Interna- 
tional Harvester, Chrysler, and Ford supported 
the change in dry surface skid number without 
qualification, and Wliite suggested that a skid 
number of 85 be utilized. The agency finds that 
the AMC and Freightliner requests for further 
delay are unjustified. 



PART 571; S 122— PRE 11 



Effective: June 14, 1976 



Ford and Freightliner asked that the skid 
number for the lower coefficient (wet) surface 
also be adjusted. The agency's purpose in pro- 
posing the adjustment is limited to changes nec- 
essary to avoid a modification of the t«st surfaces 
or an increase in the severity of performance 
levels specified under the safety standards. The 
NHTSA earlier concluded that change of the wet 
surface specification was unnecessai-y, and no 
evidence has been supplied that would modify 
the earlier determination. 

General Motors noted that an editorial change 
to the newer ASTM procedure does not appear 
in early publications of that procedure. To put 
all interested persons on notice of the editorial 
change, the NHTSA has included the change in 
its references to the ASTM E274-70 procedure. 

Freightliner asserted that the newei- procedure 
included modification of a formula that justified 
a larger upwards adjustment than that proposed 
by the agency. Actually, the modifications only 
corrected an error in the earlier formida which 
had no effect on the determination of frictional 
coefficient. Manufacturers either utilized a test 
trailer that obviated the need for calculations 
using the formula, or were aware of the error 
and corrected for it in their calculations. Thus 
the adjustment requested by Freightliner is not 
warranted. 

In accordance with recently-enunciated De- 
partment of Transportation policy encouraging 
adequate analysis of the consequences of regida- 
tory action (41 FR 16201, April 16, 1976), the 
agency herewith summarizes its evaluation of the 
economic and other consequences of this amend- 
ment on the public and private sectors, including 
possible loss of safety benefit. Because the new 
references to procedures and a test tire are ex- 
pected to accord with existing practices, the 
amendment is judged not to have any significant 
impact on costs or benefits of the standards and 



consumer information item that are modified by 
the change. 

Standard No. 121, Air Brake Systems, is pres- 
ently subject to judicial review under § 105(a) 
of the National Traffic and Motor Vehicle Safety 
Act (15 U.S.C. § 1394(a)). The U.S. Court, of 
Appeals hearing the petition for review has indi- 
cated that it prefers to review the standard as it 
presently exists, without unnecessary amendment. 
To the degree possible, the agency is complying 
with that request and therefore, in the case of 
Standard No. 121, will delay the update of 
ASTM procedure until review is completed. 

It is noted that this change in procedure for 
ascertaining the frictional resistance of the test 
surface does not invalidate data collected using 
the older procedure, and manufacturers can pre- 
sumably certify on the basis of stopping distance 
tests conducted on surfaces measured by the old 
tire. 

In consideration of the foregoing, amendments 
are made in Chapter V of Title 49, Code of 
Federal Regulations. 

Effective date: June 14, 1976. Because the 
older test tire is no longer manufactured, and 
because the amendment of procedure and test tire 
is intended only to duplicate the existing pro- 
cedure and tire, this amendment creates no addi- 
tional requirements for any person, and an 
immediate effective date is found to be in the 
public interest. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407); delegation of authority 
at 49 CFR 1.50.) 

Issued on June 8, 1976. 

James B. Gregory 
Administrator 

41 F.R. 24592 
June 17, 1976 



PART 571; S 122— PRE 12 



Effective: October 10, 1978 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 122 

(Docket No. 78-14; Notice 1) 

Motorcycle Brake Systems 



This notice amends Motor Vehicle Safety 
Standard Xo. 122 Motorcycle Brake Systems, to 
incorporate an interpretation, clarifying that the 
parking brake system test for a 3-wheeled motor- 
cycle does not require that a vehicle be held on 
a 30 percent grade for 5 minutes if the limit of 
traction of its braked wheels is reached on a 
lower grade so that the vehicle begins to slide. 
This notice also amends the standard to clarify 
the conditions under which ti'action is deter- 
mined. The action is occasioned by a recent in- 
terpretation of the agency provided in response 
to a petition for temporary exemption from 
Standard Xo. 122 by Daihatsu Motor Company 
whose B-20 vehicle's limit of traction was reached 
on a 20 percent grade (43 F.R. 36548). The 
amendment has no effect upon safety since it is 
a statement and clarification of an existing 
agency interpretation. 

Effective date: As an interpretative rule, the 
amendment is effective upon publication in the 
Federal Register. October 10, 1978. 

For further information contact: 

Scott Shadle, Office of Rulemaking, Xational 
Highway Traffic Safety Administration. 
AVashington, D.C. 20590 "(202-426-2153). 

Supplementary information : Paragraph So.6 
of 40 CFR 571.122, Motor Vehicle Safety Stand- 
ard Xo. 122, requires in part that the parking- 
brake system for a 3-wheeled motorcycle "be 
capable of holding the motorcycle, for 5 minutes 
in both forward and reverse directions, on a 30 
percent grade. . . ." Recently the agency enter- 
tained a petition from Daihatsu Motor Company, 
Ltd. for a renewal of an exemption granted an 
electric motor-driven cycle in 1976 because of the 
inability of its braked wheels to hold it on a 
30 percent grade in tlie reverse direction. The 
agency disposed of the petition by publishing 
an interpretation allowing Daihatsu to certify 
compliance with Standard Xo. 122, stating that 



tlie agenc}' did not intended "to dictate design 
requirements such as center of gravity location 
and tire design mandating that the vehicle itself 
have a limit of traction sufficient to hold it on 
a grade that is 30 percent or greater when its 
wheels are braked." (43 F.R. 36548) 

XHTSA has decided to incorporate this inter- 
pretation into Standard Xo. 122 by appropriate 
amendments to the parking brake system require- 
ment (S5.6) and test procedures (S7.9). A 
similar limit-of-traction provision already exists 
with respect to the parking brake system require- 
ments for hydraulically braked vehicles (para- 
graph S5.2.1 of 49 CFR 571.105). 

This notice also amends Standard Xo. 122 to 
set forth the road surface on which traction is 
to be determined. As in the case of the parking 
lirake test conditions in paragraph S6.9 of 49 
CFR 571.105 and paragraph S5.6.2 of 59 CFR 

571.121, Air Brake Systems, this notice specifies 
a surface of clean, dry, smooth portland cement 
concrete. 

Because the amendment is an interpretative 
rule, under the Administrative Procedures Act 
it may be adopted without prior notice and public 
comnient (5 U.S.C. 553(b)). 

The principal authors of this amendment are 
Taylor Vinson of the Office of Cliief Counsel and 
John Carson of the Office of Rulemaking. 

In consideration of the foregoing, 49 CFR 

571.122, Motor Vehicle Safety Standard Xo. 122 
is amended. . . . 

(Sees. 103. 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392. 1407); delegation of authority 
at 49 CFR 1.50.) 

Issued on October 3, 1978. 

Joan Claybrook 
Administrator 

43 F.R. 46547-46548 
October 10, 1978 



PART 571; S 122— PRE 13-14 



MOTOR VEHICLE SAFETY STANDARD NO. 122 
Motorcycle Brake Systems 



51. Scope. This standard specifies perform- 
ance requirements for motorcycle brake systems. 

52. Purpose. The purpose of the standard is 
to insure safe motorcycle braking performance 
under normal and emergency conditions. 

53. Application. This standard applies to 
motorcycles. 

54. Definitions. 

"Braking interval" means the distance meas- 
ured from the start of one brake application to 
the start of the next brake application. 

"Initial brake temperature" means the tem- 
perature of the hottest service brake of the vehicle 
0.2 miles before any brake application. 

"Skid number" means the frictional resistance 
of a pavement measured in accordance with 
American Society for Testing and Materials 
(ASTM) Method E-274-70 (as revised July 
1974) at 40 mph, omitting water delivery as 
specified in paragraphs 7.1 and 7.2 of that 
method. 

"Stopping distance" means the distance 
traveled by a vehicle from the start of the brake 
application to the point where the vehicle stops. 

"Split service brake system" means a brake 
system consisting of two or more subsystems 
actuated by a single control designed so that a 
leakage-type failure of a pressure component in 
a single subsystem (except structural failure of 
a housing that is common to all subsystems) shall 
not impair the operation of the other sub- 
system(s). 

S.5 Requirements. Each motorcycle shall 
meet the following requirements under the con- 
ditions specified in S6, when tested according 
to the procedures and in the sequence specified 
in S7. Corresponding test procedures of S7 are 
indicated in parentheses. If a motorcycle is in- 



T.\BLE I 

STOPPING DISTANCES FOR EFFECTIVENESS. FADE AND 

PARTUL SYSTEM TESTS 

Stopping distance, feet 

Effectiveness tests 

Vehicle Prebur- Prebur- Effective- Effective- 
test nish effec- nish effec- ness total ness partial 
speed tiveness tiveness system hydraulic 
m.p.h. total partial (S5.4) systems 
system mechani- (S5.7.1) (S5.7,2) 
(S5.2.1) cal systems 
(S5.2.2) 

I n ui rv 

15 13 30 il 25 

20 24 54 19 44 

25 37 84 30 68 

30 54 121 43 97 

35 74 165 58 132 

40 96 216 75 173 

45 121 273 95 218 

50 150 337 128 264 

55 181 407 155 326 

60 216 484 185 388 

65 217 415 

70 264 527 

75 . . _ 303 606 

80 _. __.... 345 689 

85 389 788 

90 484 872 

95 540 971 

100 _ . ._ 598 1076 

105 659 1188 

110 _ _ 723 1302 

115 ._ . 791 1423 

120 .. 861 1549 



TABLE II 






BRAKE TEST SEQUENCE AND 


REQUIREMENTS 




SEQUENCE L.C. 


Test pro- 


Require- 




cedure 


ments 




S7.2 




2. First (Prebumish) effectivess test: 




(a) Service brake system 


S7.3.1 


S5.2.1 


(b) Partial service brake system 


S7.3.2 


S5.2.2 


3. Burnish procedure 


S7.4 




4. Second effectiveness test 


S7.5 


S5.3 


5. First fade and recovery test 


S7.6 


S5.4 


6. Rebumish 


S7.7 




7, Final effectiveness test: 








S7.8.1 


S5.5.1 




S7.8.2 


S5.5.2 


8. Parking brake test 






{three-wheeled motorcycles only) 


S7.9 


S5.6 


9. Water recovery test 


_ S7.10 


S5.8 


10. Design durability 


. S7.ll 


S5.8 









PART 571; S 122-1 



capable of attaining a specified speed, its service 
brakes shall be capable of stopping the vehicle 
from the multiple of 5 mph that is 4 mph to 
8 mph less than the speed attainable in 1 mile, 
within stoppping distances that do not exceed 
,the stopping distances specified in Table 1. 

S5.1 Required equipment— split service brake 
system. Each motorcycle shall have either a 
split service brake system or two independently 
actuated service brake systems. 

55.1.1 Mechanical service brake system. 

Failure of any component in a mechanical service 
brake system shall not result in a loss of brak- 
ing ability in the other service brake system on 
the vehicle. 

55.1.2 Hydraulic service brake system. A 

leakage failure in a hydraulic service brake system 
shall not result in a loss of braking ability in 
the other service brake system on the vehicle. 
Each motorcycle equipped with a hydraulic 
brake system shall have the equipment specified 
in S5.1.2.1 and S5.1.2.2. 

55. 1.2.1 Master cylinder reservoirs. Each 
master cylinder shall have a separate reservoir 
for each brake circuit, with each reservoir filler 
opening having its own cover, seal, and cover 
retention device. Each reservoir shall have a 
minimum capacity equivalent to one and one-half 
times the total fluid displacement resulting when 
all the wheel cylinders or caliper pistons serv- 
iced by the reservoir move from a new lining, 
fully retracted position to a fully worn, fully 
applied position. Where adjustment is a factor, 
the worst condition of adjustment shall be used 
for this measurement. 

55.1.2.2 [Reservoir labeling. Each motorcycle 
shall have a brake fluid warning statement that 
reads as follows, in letters at least 3/32 of an 
inch high: 

"WARNING: Clean filler cap before removing. 

Use only fluid from a sealed container." 

(Inserting the recommended type of brake fluid 
as specified in 49 CFR § 571.116, e.g. DOT 3) 
The lettering shall be— 

(a) Permanently affixed, engraved or em- 
bossed; 

(b) Located so as to be visible by direct view, 
either on or within 4 inches of the brake fluid 
reservoir filler plus or cap; and 



(c) Of a color that contrasts with its back- 
ground, if it is not engraved or embossed. 

S5.1.3. Split service brake system. In addition 
to the equipment requu*ed by S5.1.2 each motor- 
cycle equipped with a split service brake system 
shall have a failure indicator lamp as specified 
inS5.1.3.1. 

S5.1.3.1 Failure indicator lamp. 

(a) One or more electrically operated service 
brake system failure indicator lamps that is 
mounted in front of and in clear view of the 
driver, and that is activated— 

(1) In the event of pressure failure in any 
part of the service brake system, other than a 
structural failure of either a brake master cyl- 
inder body in a split integral body type master 
cylinder system or a service brake system 
failure indicator body, before or upon appli- 
cation of not more than 20 pounds of pedal 
force upon the service brake. 

(2) Without the application of pedal force, 
when the level of brake fluid in a master cylin- 
der reservoir drops to less than the recom- 
mended safe level specified by the manufac- 
turer or to less than one-half the fluid reservoir 
capacity, whichever is the greater. 

(b) All failure indicator lamps shall be acti- 
vated when the ignition switch is turned from 
the "off" to the "on" or to the "start" position. 

(c) Except for the momentary activation re- 
quired by S5. 1.3. 1(b), each indicator lamp, once 
activated, shall remain activated as long as the 
condition exists, whenever the ignition switch is 
in the "on" position. An indicator lamp acti- 
vated when the ignition is turned to the "start" 
position shall be deactivated upon return of the 
switch to the "on" position unless a failure exists 
in the service brake system. 

(d) Each indicator lamp shall have a red lens 
with the legend "Brake Failure" on or adjacent 
to it in letters not less than %2 of an inch high 
that shall be legible to the driver in daylight 
when lighted. 

S5.1.4 Parking Brake. Each three-wheeled 
motorcycle shall be equipped with a parking 
brake of a friction type with a solely mechanical 
means to retain engagement. 



PART 571; S 122-2 



S5.1.5 Other requirements. The brake system 
shall be installed so that the lining thickness of 
drum brake shoes may be visually inspected, 
either directly or by use of a mirror without 
removing the drums, and so that disc brake 
friction lining thickness may be visually inspected 
without removing the pads. 

S5.2 Service Brake System. First (pre- 
bumish) effectiveness. 

S.5.2.1 Service bral<e system. The service 
brakes shall be capable of stopping the motor- 
cycle from 30 mph and 60 mph within stopping 
distances which do not exceed the stopping dis- 
tances specified in Column I of Table I (S7.3.1). 

S5.2.2 Partial service brake system. Each in- 
dependently actuated service brake system on 
each motorcycle shall be capable of stopping the 
motorcycle from 30 mph and 60 mph within 
stoping distances which do not exceed the stop- 
ping distances specified in Column II of Table I 
(S7.3.2). 

S.5.3 Service brake system— second effective- 
ness. The service brakes shall be capable of 
stopping the motorcycle from 30 mph, 60 mph, 
80 mph, and the multiple of 5 mph that is 4 mph 
to 8 mph less than the speed attainable in 1 mile 
if this speed is 95 mph or greater, within stop- 
ping distances that do not exceed the stopping 
distances specified in Column III of Table I 
(S7.5). 

S5.4 Service brake system— fade and recovery. 

These requirements do not apply to a motor- 
driven cycle whose speed attainable in 1 mile is 
30 mph or less. 

S.5.4.1 Baseline check— minimum and maxi- 
mum pedal forces. The pedal and lever forces 
used in establishing the fade baseline check aver- 
age shall be within the limits specified in S6.10 
(S7. 6. 1). 

55.4.2 Fade. Each motorcycle shall be ca- 
pable of making 10 fade stops from 60 mph at 
not less than 15 fpsps for each stop (S7.6.2). 

55.4.3 Fade recovery. Each motorcycle shall 
be capable of making five recovery stops with a 
pedal force that does not exceed 90 pounds, and 
a hand lever force that does not exceed 55 pounds 



for any of the &st four recovery stops and that 
for the fifth recovery stop is within plus 20 
pounds and minus 10 pounds of the fade test 
baseline check average force (S7.6.3). 

55.5 Service brake system— final effectiveness. 

These requirements do not apply to a motor- 
driven cycle whose speed attainable in 1 mile is 
30 mph or less. 

55.5.1 Service brake system. The service 
brakes shall be capable of stopping the motor- 
cycle in a manner that complies with S5.3 
(S7.8.1). 

55.5.2 Hydraulic service brake system— partial 
failure. In the event of a pressure component 
leakage failure, other than a structural failure 
of either a brake master cylinder body in a split 
integral body type master cylinder system or a 
service brake system failure indicator body, the 
remaining portion of the service brake system 
shall continue to operate and shall be capable of 
stopping the motorcycle from 30 mph and 60 
mph within stopping distances that do not exceed 
the stopping distances specified in Column IV 
of Table I (S7.8.2). 

55.6 Parking brake system. The parking 
brake system shall be capable of holding the 
motorcycle stationary (to the limits of traction 
of the braked wheels), for 5 minutes, in both 
forward and reverse directions, on a 30 percent 
grade, with an applied force of not more than 
90 pounds for a foot-operated system and 55 
pounds for a hand-operated system (S7.9). 

55.7 Service brake system— water recovery. 

55.7.1 Baseline check. The pedal and lever 
forces used in establishing the water recovery 
baseline check average shall be within the limits 
specified in S6. 10(87.10.1). 

55.7.2 Water recovery test. Each motorcycle 
shall be capable of making five recovery stops 
with a pedal force that does not exceed 90 pounds, 
and a hand lever force that does not exceed 55 
pounds, for any of the first four recovery stops, 
and that for the fifth recovery stop is within 
plus 20 pounds and minus 10 pounds of the base- 
line check average force (S7.10.2). 



PART 571; S 122-3 



S5.8 Service brake system design durability. 

Each motorcycle shall be capable of completing 
all braking requirements of S5 without detach- 
ment of brake linings from the shoes or pad, 
detachment or fracture of any brake system com- 
ponents, or leakage of fluid or lubricant at the 
wheel cyclinder and master cylinder reservoir 
cover, seal, or retention device (S7.ll). 

S6. Test conditions. The requirements of S5 
shall be met under the following conditions. 
Where a range of conditions is specified, the 
motorcycle shall be capable of meeting the re- 
quirements at all points within the range. 

56.1 Vehicle weight. Motorcycle weight is 
unloaded vehicle weight plus 200 pounds (includ- 
ing driver and instrumentation), with the added 
weight distributed in the saddle or carrier if so 
equipped. 

56.2 Tire inflation pressure. Tire inflation 
pressure is the pressure recommended by the 
manufacturer for the vehicle weight specified in 
paragraph S6.1. 

56.3 Transmission. Unless otherwise speci- 
fied, all stops are made with the clutch disen- 
gaged. 

56.4 Engine. Engine idle speed and ignition 
timing settings are according to the manufac- 
turer's recommendations. If the vehicle is 
equipped with an adjustable engine speed gov- 
ernor, it is adjusted according to the manufac- 
turer's recommendation. 

56.5 Ambient temperature. The ambient tem- 
perature is between 32° and 100° F. 

56.6 Wind velocity. The wind velocity is 
zero. 

56.7 Road surface. Road tests are conducted 
on level roadway having a skid number of 81. 
The roadway is 8 feet wide for two-wheeled 
motorcycles, and overall vehicle width plus 5 
feet for three- wheeled motorcycles. The park- 
ing brake test surface is clean, dry, smooth port- 
land cement concrete. 

56.8 Vehicle position. The motorcycle is 
aligned in the center of the roadway at the start 



of each brake application. Stops are made with- 
out any part of the motorcycle leaving the road- 
way and without lockup of any wheel. 

S6.7 Thermocouples. The brake temperature 
is measured by plug-type thermocouples installed 
in the approximate center of the facing length 
and width of the most heavily loaded shoe or 
disc pad, one per brake, as shown in Figure 1. 




CB DRILL NO 31 
100 MAX DEPTH 
BEFORE GRIND 



FIGURE 1 

TYPICAL PLUG TYPE 
THERMOCOUPLE INSTALLATIONS 



S6.10 Brake actuation forces. Except for the 
requirements of the fifth recovery stop in S5.4.3 
and S5.7.2 (S7.6.3 and S7.10.2) the hand lever 
force is not less than five and not more than 55 
pounds and the foot pedal force is not less than 
10 and not more than 90 pounds. The point of 
initial application of the lever forces is 1.2 inches 
from the end of the brake lever grip. The direc- 
tion of the force is perpendicular to the handle 
grip on the plane along which the brake lever 
rotates, and the point of application of the pedal 
force is the center of the foot contact pad of the 
brake pedal. The direction of the force is per- 
pendicular to the foot contact pad on the plane 
along which the brake pedal rotates, as shown 
in Figure 2. 



PART 571; S 122-4 



FIG. 2 DIRECTION OF FORCE 





BRAKE LEVER 



IBRAKE PEDAL 



S7. Test procedures and sequence. Each 
motorcycle shall be capable of meeting all the 
requirements of this standard when tested accord- 
ing to the procedures and in the sequence set 
forth below without replacing any brake sys- 
tem part, or making any adjustments to the brake 
system other than as permitted in S7.4. A motor- 
cycle shall be deemed to comply with S5.2, S5.3 
and S5.5 if at least one of the stops specified 
in S7.3, S7.5 and S7.8 is made within the stop- 
ping distances specified in Table I. 

57.1 Braking warming. If the initial brake 
temperature for the first stop in a test procedure 
(other than S7.10) has not been reached, heat 
the brakes to the initial brake temperature by 
making up to 10 stops from 30 mph at a decelera- 
tion of not more than 10 fpsps. On independ- 
ently operated brake systems, the coldest brake 
shall be within 10° F of the hottest brake. 

57.2 Pretest Instrumentation check. Conduct 
a general check of test instrumentation by mak- 
ing not more than 10 stops from a speed of not 
more than 30 mph at a deceleration of not more 
than 10 fpsps. If test instrument repair, replace- 
ment, or adjustment is necessary, make not 
more than 10 additional stops after such repair, 
replacement or adjustment. 

57.3 Service brake system - first (preburnished) 
effectiveness test. 

57.3.1 Service brake system. Make six stops 
from 30 mph and then six stops from 60 mph 
with an initial brake temperature between 130° F 
and 150° F. 

87.3.2 Partial service brake system. For a 

motorcycle with two independently actuated serv- 
ice brake systems, repeat S7.3.1 using each service 
brake system individually. 



57.4 Service brake system— burnish procedure. 

Burnish the brakes by making 200 stops from 
30 mph at 12 fpsps. The braking interval shall 
be either the distance necessary to reduce the 
initial brake temperature to between 130° F and 
150° F or 1 mile, whichever occurs first. Accel- 
erate at maximum rate to 30 mph immediately 
after each stop and maintain that speed until 
making the next stop.. After burnishing adjust 
the brakes in accordance with the manufacturer's 
recommendation. 

87.5 Service brake system— second effective- 
ness test. Repeat S7. 3.1. Then, make four stops 
from 80 mph and four stops from the multiple 
of 5 mph that is 4 mph to 8 mph less than the 
speed attainable in 1 mile if that speed is 95 mph 
or greater. 

87.6 Service brake system— fade and recovery 
test. These requirements do not apply to a 
motor-driven cycle whose speed attainable in 1 
mile is 30 mph or less. 

87.6.1 Baseline check stops. Make three stops 
from 30 mph at 10 to 11 fpsps for each stop. 
Compute the average of the maximum brake 
pedal forces and the maximum brake lever forces 
required for the three stops. 

87.6.2 Fade stops. Make 10 stops from 60 
mph at not less than 15 fpsps for each stop. 
The initial brake temperature before the first 
brake application shall be between 130° F and 
150° F. Initial brake temperatures before brake 
appHcations for subsequent stops shall be those 
occurring at the distance intervals. Attain the 
required deceleration as quickly as possible and 
maintain at least this rate for not less than three- 
fourths of the total stopping distance for each 
stop. The interval between the starts of service 
brake applications shall be 0.4 mile. Drive 1 
mile at 30 mph after the last fade stop and im- 
mediately conduct the recovery test specified in 
S7.6.3. 

87.6.3 Recovery test. Make five stops from 
30 mph at 10 to 11 fpsps for each stop. The 
braking interval shall not be more than 1 mile. 
Immediately after each stop accelerate at maxi- 
mum rate to 30 mph and maintain that speed 
until making the next stop. 



PART 571; S 122-5 



S7.7 Service brake system— reburnish. Re- 
peat S7.4 except make 35 burnish stops instead 
of 200 stops. Brakes may be adjusted after re- 
burnish if no tools are used. These require- 
ments do not apply to a motor-driven cycle whose 
speed attainable in 1 mile is 30 mph or less. 



57.8 Service brake system— final effectiveness 
test. These requirements do not apply to a 
motor-driven cycle whose speed attainable in 1 
mile is 30 mph or less. 

57.8.1 Service brake system. Repeat S7.5 
including S7.3.1. 

57.8.2 Partial service brake system test. 

Alter the service brake system on three-wheeled 
motorcycles to induce a complete loss of braking 
in any one subsystem. Determine the line pres- 
sure or pedal force necessary to cause the brake 
system failure indicator to operate. Make six 
stops from 30 mph and then six stops from 60 
mph with an initial brake temperature between 
130° F and 150° F. Repeat for each subsystem. 
Determine that the brake failure indicator is 
operating when the master cylinder fluid level 
is less than the level specified in S5. 1.3. 1(a) (2), 
and that it complies with S5. 1.3. 1(c). Check 
for proper operation with each reservoir in turn 
at a low level. Restore the service brake system 
to normal at completion of this test. 

57.9 Parking brake test. Starting with an 
initial brake temperature of not more than 
150° F drive the motorcycle downhill on the 
30 percent grade with the longitudinal axis of 
the motorcycle in the direction of the grade. 
Apply the service brakes with a force not ex- 
ceeding 90 pounds to stop the motorcycle and 
place the transmission in neutral. Apply the 
parking brake by exerting a force not exceeding 
those specified in S5.6 Release the service 
brake and allow the motorcycle to remain at rest 
(to the limit of traction of the braked wheels) 
for 5 minutes. Repeat the test with the motor- 
cycle parked in the reverse (uphill) position on 
the grade. 



57.10 Service brake system— water recovery 
test. 

57.10.1 Baseline check stops. Make three 
stops from 30 mph at 10 to 11 fpsps for each 
stop. Compute the average of the maximum 
brake pedal forces and of the maximum brake 
lever forces required for the three stops. 

57.10.2 Wet brake recovery stops. Com- 
pletely immerse the rear brake assembly of the 
motorcycle in water for 2 minutes with the 
brake fully released. Next completely immerse the 
front brake assembly of the motorcycle in water 
for 2 minutes with the brake fully released. 
Perform the entire wetting procedure in not more 
than 7 minutes. Immediately after removal 
of the front brake from water, accelerate at a 
maximum rate of 30 mph without a brake appli- 
cation. Immediately upon reaching that speed 
make five stops, each from 30 mph at 10 to 
11 fpsps for each stop. After each stop (except 
the last) accelerate the motorcycle immediately 
at a maximum rate to 30 mph and begin the 
next stop. 

57.11 Final inspection. Upon completion of 
all the tests inspect the brake system in an as- 
sembled condition, for compliance with the brake 
lining inspection requirements. Disassemble all 
brakes and inspect: 

(a) The entire brake system for detachment 
or fracture of any component; 

(b) Brake linings for detachment from the 
shoe or pad; 

(c) Wheel cylinder, master cylinder, and axle 
seals for fluid or lubricant leakage; 

(d) Master cylinder for reservoir capacity 
and retention device; and 

(e) Master cylinder label for compliance with 
S5.1.2.2. 



37 F.R. 5033 
March 9, 1972 



PART 571; S 122-6 



Eflactivt: S*ptomb*r 1, 1974 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 123 

Motorcycle Controls and Displays 
(Docket No. 70-26; Notice 3) 



This notice amends Part 571 of Title 49, Code 
of Federal Regulations, to add a new Motor 
Vehicle Safety Standard No. 123 (49 CFR 
§ 571.123) that establishes requirements for 
motorcycle controls and displays. A notice of 
proposed rulemaking on this subject was pub- 
lished on November 6, 1970 (35 F.R. 17117). 

The National Highway Traffic Safety Admin- 
istration estimates that over 3,000 accidents may 
be avoided annually by specifying a uniform 
standard for motorcycle controls and displays. 
As this agency commented in the prior notice: 
"Controls and displays link the operator and the 
machine, and if there is confusion as to their 
location, interpretation, or operation, a danger- 
ous situation may result. A cyclist, especially 
the novice and the cyclist who has changed from 
one make of machine to another, must not hesi- 
tate when confronted with an emergency." The 
purpose of the new standard is to minimize 
operator error in responding to the motoring 
environment, by standardizing certain motor- 
cycle controls and displays. 

The basic operational requirement of Standard 
No. 123 is that handlebar-mounted controls be 
operable throughout their full range without the 
operator removing his hand from the handgrip. 
Standard No. 1^ re quire s att motorcycles to 
have a supplemental engine stop control, oper- 
able from the right handlebar, intended for use 
in emergency situations. Notice of this require 
ment was proposed in Notice 2 to Docket No. 
69-20, Accelerator Control Systems (35 F.R. 
15241). Standard No. 123 also requires that if 
any of ten other specified equipment items are 
provided on a motorcycle, the location and 
method of operation of the applicable control 
shall be standardized. These items are : manual 
clutch or integrated clutch and gear change, 



foot-operated gear change, headlamp upper- 
lower beam control, horn, turn signal lamps, 
ignition, manual fuel shutoff control, twist-grip 
throttle, front wheel brake, and rear wheel 
brakes. Motorcycles that are designed and sold 
exclusively for use by law enforcement agencies 
are excluded from Standard No. 123, as the 
configuration of certain controls on such vehicles, 
necessary for law enforcement purposes, differs 
from that required by the new standard. Pro- 
posals applicable to the instrument illumination 
intensity control, the electric starter, and the 
kick starter have not been adopted as insufficient 
correlation with motor vehicle safety has been 
found for these items. 

As noted below, some of the location and op- 
erational requirements that were proposed have 
not been adopted in the following instances 
Otherwise, the location and operation of controls 
are required as proposed. 

1. F oot-of crated gear change. The likelihood 
of inadvertent engagement of reverse gear has 
been found to be so slight that a means to pro- 
hibit it has not been found necessary. Further, 
no requirement has been specified for location of 
neutral gear. Under Proposal A, neutral would 
have occurred lowest in the gear sequence. Pro- 
posal A Tvas not adopted because of the likeli- 
hood of overshooting low gear when downshift- 
ing, thus contributing to a possible loss of 
control. In Proposal B, the transmission would 
be put into neutral by a rearward motion of the 
operator's heel on a control device separate from 
the shift lever. This method was not adopted 
since it appears to have no inherent safety ad- 
vantages over any other means of finding neutral. 
The intent of Proposal B was to ensure that 
neutral can reliably be selected when desired 
without being selected inadvertently when not 



PART 571; S 123— PRE 1 



Effective: September 1, 1974 



desired. The conventional neutral light may 
serve as an aid to such shifting; however, any 
system which requires eye movements away from 
the road merely to shift gears cannot be consid- 
ered to be an adjunct to safety. 

The present standard does not impose specific 
requirements for ease of locating the gear posi- 
tion, or for protection against inadvertent shift- 
ing into neutral. However, the Administration 
considers these to be desirable objectives and 
will consider amending the standard if it ap- 
pears necessary to do so. 

2. Headlamf control. Because heavy gloves 
are needed for safe riding, only a simple "up for 
higher beam, down for lower beam" requirement 
has been adopted. 

3. Turn signal lamps. Because turn signal 
lamps are not a required item of motorcycle 
equipment until January 1, 1973, and the indus- 
try is experimenting with various controls. 
Standard No. 123 specifies only that the turn 
signal lamp control be located on the handlebars. 

4. Igniticn: Because of the adoption of the 
requirement that motorcycles be equipped with 
a supplemental engine stop control on the right 
handlebar, the need to specify a location and 
method of operation for the ignition has dimin- 
ished. Accordingly, the sole ignition control 
requirement is that the "off" position be counter- 
clockwise from all other positions. 

5. Manual fuel shuto-ff control. The require- 
ments adopted do not apply to automatic fuel 
shutoff controls. No location for a manual con- 
trol is specified. Based upon comments, revisions 
have been made in the direction of valve oper- 
ation. 

Substantial modifications have been made as 
well in the display proposals. Because of the 
limited range within which displays can be lo- 



cated on a motorcycle, it has been determined 
that no specific location requirements are neces- 
sary. Illumination of the neutral position and 
the speedometer has been deemed essential ; the 
proposal that a green lamp indicate neutral po- 
sition has been adopted, and the speedometer 
must be illuminated whenever the headlamp is 
activated. Because turn signals and upper beam 
indicators are covered in Standard No. 108, they 
have been omitted from the display illumination 
requirements of Standard No. 123. 

Proposals for control identification, stands, 
and passenger foot-rests have been adopted sub- 
stantially as proposed. Since operating instruc- 
tions are invariably provided with motorcycles, 
the NHTSA has not adopted the proposal cov- 
ering them. 

Effective date: September 1, 1974. Because 
of the leadtime necessary for preparation for 
production, it is found, for good cause shown, 
that an effective date later than one year after 
the issue date is in the public interest. 

In consideration of the foregoing, Title 49, 
Code of Federal Regulations, is amended by 
adding § 571.123, Motor Vehicle Safety Standard 
No. 123, Motorcycle Controls and Displays, as 
set forth below. 

This notice is issued under the authority of 
sections 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act of 1966 (15 U.S.C. 
1392, 1407) and the delegation of authority from 
the Secretary of Transportation to the National 
Highway Traffic Safety Administrator, 49 CFR 
1.51. 



Issued on April 4, 1972. 



Douglas W. Toms 
Administrator 

37 F.R. 7207 
April 12, 1972 



PART 571; S 123— PRE 2 



Effcctiv*: Scptambtr 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 123 

Motorcycle Controls and Displays 



This notice responds to petitions for recon- 
sideration of Motor Vehicle Safety Standard 
No. 123 (49 CFR §571.123) and amends the 
standard in minor respects. 

Motor Vehicle Safety Standard No. 123, 
establishing requirements for the location, op- 
eration, identification, and illumination of 
motorcycle controls and displays, effective 
September 1, 1974, was published on April 12, 
1972 (37 F.R. 7207). Thereafter, pursuant to 49 
CFR § 553.35, petitions for reconsideration of the 
rule were filed by Japan Automobile Manufac- 
turers Asociation, Inc. ("JAMA"), Kawasaki 
Motors Corp. (Kawasaki), and Cushman 
Motors ("Cushman") through counsel. In re- 
sponse to these petitions the standard is being 
revised in minor respects. The Administrator 
has declined to grant requested relief from other 
requirements of the standard. 

1. Manual fuel shutoff valve. Standard No. 
123 requires that the manual fuel shutoff control 
point downward when in the "on" position, for- 
ward in the "off" position, and upward to supply 
fuel from a reserve source if one is provided. 

JAMA has requested that the configuration 
found on most Japanese motorcycles be adopted : 
"off" with the control position to the left, "re- 
serve" to the right, and "on" downward. 
JAMA's request was originally made in response 
to the notice proposing control positions for the 
shut-off valve, and was considered at that time. 
JAMA's petition is denied. The NHTSA has 
determined that the control should be stand- 
ardized by requiring its operation along a longi- 
tudinal rather than a transverse axis. In this 
location there is a greater likelihood that in the 
event of a crash, the control will be carried by 
inertia to the off position, thereby shutting off 
the fuel. 

JAMA also asked for an interpretation of the 
words "control pointing" asking if the words 



mean the direction of a non-operational pointer 
indicating the off-position, or the direction of the 
control end operated by the fingers. "Control 
pointing" means the direction of the control end 
operated by the fingers. To eliminate this pos- 
sible ambiguity, the word "pointing" is deleted 
from the entry in Table I. 

2. Headlamf control. The NHTSA requires, 
in Standard No. 123, that the upper headlamp 
beam be activated with an upward motion of the 
beam control, and the lower beam by a down- 
ward motion. Kawasaki has asked that these 
positions be reversed. It reasons that when the 
left thumb is under the handlebar, the lower 
beam control can be more quickly activated with 
an upward movement of the thumb, rather than 
by raising the thumb above the switch and then 
depressing it. The Administration denies 
Kawasaki's request, as it is considered contrary 
to good human factors engineering. Control 
mechanisms which are used for increasing the 
output of a system are generally designed to be 
switched upward for higher intensity. 

3. Speedometer graduations. Both JAMA 
and Kawasaki have petitioned for reconsidera- 
tion of the requirement that major and minor 
graduations and numerals appear at the 10 and 
5 mph intervals respectively, alleging that op- 
erator confusion could be caused by a clutter of 
numerals and graduations at 5 mph intervals. 
The NHTSA considers these petitions to have 
merit and is amending Standard No. 123, to re- 
quire only minor graduations at the 5 mph 
intervals. 

4. Control identification. JAMA has peti- 
tioned for an amendment of Table 3 to eliminate 
identification of some controls and to identify 
only control positions. The petition also re- 
quested abbreviation of the identification pres- 
ently required. JAMA alleges difficulty in pro- 
viding all the identification marks due to lack of 



PART 571; S 123— PRE 3 



space around the handlebar. It argues that an 
individual operator will not mistake one equip- 
ment item for another on different cycles when 
all controls are uniformly located as specified by 
Standard No. 123. 

The Administration denies JAMA's petition. 
Labeling control positions without identifying 
the control itself could confuse the novice motor- 
cyclist and may contribute to traffic hazards. 
During the initial learning stage the cyclist will 
not be able to identify controls by their required 
location. Further, there are no common ab- 
breviations with universal acceptance for the 
controls mentioned, viz., choke, starter, horn, and 
neutral indicator. 

JAMA also requested a clarification as to 
whether control identification must be indicated 
in capital letters. The answer is no: use of 
upper or lower case lettering is at the manu- 
facturer's discretion. Kawasaki asked whether 
it is permissible to add information to the 
tachometer identification indicating that it 
registers thousands of revolutions per minute. 
The marking requirements of the standard are 
minimum requirements only, and the NHTSA 
has no objection to further identification of this 
nature for the tachometer. 

5. Three-wheeled motorcycles. Cushman man- 
ufactures three-wheeled motorcycles. It alleged 
that many of the requirements of Standard No. 
123 are incompatible with the configuration of its 
vehicle. It requested that Standard No. 123 be 
amended to exclude three-wheeled motorcycles 
that are designed to achieve a maximum speed 
no greater than 40 mph. Cushman raised a 
number of specific objections concerning control 
location and operation, identification, and dis- 
plays. In view of the disposition of Cushman's 
petition it is not necessary to discuss the objec- 
tions in detail. 



Cushman's petition is denied for the following 
reasons. Petitioner manufactures two types of 
three-wheeled vehicles, identical except for steer- 
ing configuration. One type employs handlebars, 
the other a steering wheel. Its sales literature 
indicates that most models manufactured with 
handlebars are intended for industrial applica- 
tions on private property, and are not intended 
to be licensed as motor vehicles for use on the 
public roads. The remaining models manufac- 
tured with handlebars are intended for police 
use. Standard No. 123 does not apply to this 
type of vehicle. Cushman's models intended for 
street use are equipped with the steering wheel 
as standard equipment. The standard does not 
apply to motorcycles with steering wheels. A 
denial of Cushman's petition means only that, 
after September 1, 1974, three-wheeled motor- 
cycles for street use may not be sold with the 
handlebar option. 

6. Miscellaneous. A typographical error is 
corrected concerning the integrated clutch and 
gear change. 

In consideration of the foregoing, 49 CFR 
§571.123, Motor Vehicle Safety Standard No. 
123, is revised .... Effective date: September 
1, 1974, the same effective date as the standard 
as previously issued '(37 F.R. 7207). 

This notice is issued under the authority of 
sections 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act of 1966 (15 U.S.C. 
1392, 1407) and the delegation of authority at 49 
CFR 1.51. 



Issued on August 22, 1972. 



Douglas W. Toms 
Administrator 

37 F.R. 17474 
August 29, 1972 



PART 571; S 123— PRE 4 



EfFeclive: October 14, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 123 

(Docket No. 74-16; Notice 2) 



This notice amends 49 CFR 571.108, 571.122, 
and 571.123, Motor Vehicle Safety Standards 
Nos. 108, 122, and 123, to modify current re- 
quirements that apply to motor-driven cycles. 

Interested persons have been afforded an op- 
portunity to participate in the making of the 
amendment by a notice of proposed rulemaking 
published on April 12, 1974 (39 F.R. 13287) and 
due consideration has been given to all comments 
received in response to the notice, insofar as they 
relate to matters within its scope. 

The prior notice responded to petitions by 
Cycles Peugeot, Ateliers de la Motobecane, and 
S.I.N.F.A.C., manufacturers, and Bermuda Bikes, 
Inc., and Robert F. Smith, retail dealers. The 
notice proposed that a motor-driven cycle whose 
speed attainable in 1 mile is 30 mph or less need 
not be equipped with turn signal lamps, and may 
be equipped with a stop lamp with one-half the 
photometric output otherwise required. Braking 
fade and recovery requirements also would not 
apply to these low-speed vehicles. Maximum 
stopping distances values for the various tests 
would be added for test speeds of 25, 20, and 15 
mph. Finally, a braking control on the left 
handlebar would be a permissible alternative to 
the required right foot braking control. 

Tlie comments received addressed both areas 
of performance covered in the proposal, and 
areas where no standards currently exist, such 
as motors, transmissions, pedals, and a request 
for exemption from Standard No. 119, Tires for 
Vehicles Other Than Passenger Cars. As these 
latter comments cover matters beyond the scope 
of the proposal, this notice does not discuss them. 
The agency, however, has been formally peti- 
tioned for rulemaking covering transmissions 
and Standard Xo. 119, and will respond to the 
petitioners in the near future. 

The decision by NHTSA not to establish a 
separate category of vehicle was objected to by 



some commenters. In support of their request, 
they argued that the majority of motor-driven 
cycles have engines producing only 1.5 to 2 horse- 
power, and consequent low maximum speeds, re- 
ducing the need for forward lighting that is 
currently required of these vehicles. Petitioners 
submitted no data justifying their request. The 
NHTSA, however, intends to study the matter 
of forward lighting for low-powered two- 
wheeled vehicles through a research contract 
with the University of Michigan. When the 
contract is completed the agency will then decide 
whether further rulemaking is warranted. 

The proposal distinguished motor-driven 
cycles on the basis of maximum speed attainable 
in 1 mile, rather than on horsepower, and the 
value selected, 30 mph, fell within the maximum 
(40 mph) and minimum (20 mph) suggested by 
commenters. The NHTSA has concluded there- 
fore that the distinction should be adopted as 
proposed. 

Some manufacturers requested restrictive con- 
trols on power plant output, apparently in fear 
that the engine of a vehicle with a top speed of 
.30 mph or less could be modified to exceed that 
speed, and therefore cause the vehicle to no 
longer comply with the Federal standards. This 
agency has not found that course of action to be 
practicable. The various ways to modify a ve- 
hicle after purchase cannot be anticipated or 
prevented at the manufacturer level. On the 
other hand, the great majority of consumers use 
their vehicles in the form in which they were 
purchased. The motor-driven cycle category it- 
self contains a limitation of 5 horsepower, which 
will be applicable to the special lighting modi- 
fications. In the NHTSA's judgment, modifica- 
tions by consumers and the consequent equipment 
requirements should continue to be regulated at 
the State level. 



PART 571; S 123— PRE 5 



Effective: October 14, 1974 



The fact tliat the agency took no action to 
propose a reduction in existing lieadlanip re- 
quirements for motor-driven cycles was criticized 
by several manufacturers as nndulj- restrictive 
because of the low speed and power output of 
their vehicles. No justification has been shown 
for such a change. Motor-dri\-en cycles therefore 
must have sufficient generating and/or battery 
caijacity to meet the headlamp requirements. 

There was no substantive objection to the ac- 
tual proposals for omission of turn signals, re- 
cUiced stop lamp photometries, relief from brake 
fade requirements, inclusion of maximum allow- 
able stopping distances for low speeds, and rear 
brake control placement. Accordingly, the 
standards are being amended in the manner 
proposed. 

Standard No. 122 is also being amended to 
delete the final effectiveness test (S5.5) for those 
motor-driven cycles excused from the fade and 
recovery requirements. The purpose of the final 
effectiveness test is to check the stopping ability 
of the vehicle after the fade and recovery tests. 
Since this requirement has been eliminated for 
motor-driven cycles of low top-speed, the final 
effectiveness test is redundant, and an unneces- 



sary duplication of the second effectiveness test. 
No safety purpose is .ser\ed by its retention. 
Language is also added to the fade and recovery 
and final effectiveness test procedures (S7.(i, 
ST. 7, and S7.S), making it clear that they do not 
apply to motor-driven cycles whose speed attain- 
able in 1 mile is 30 mph or less. 

In consideration of the foregoing, 49 CFR 
Part 571 is amended .... 

Effective date: October 14. 1974. As the 
amendments allow new options for comjiliance, 
relieve i-estrictions, and impose no additional 
burdens on regulated persons, it is found for 
good cause shown that an effective date earlier 
than 180 days after issuance of the amendments 
is in the public interest. 

(Sec. 103, 119, Pub. L. 89-563. 80 Stat. 718, 
15 U.S.C. 1392, 1407; delegation of authority at 
49 CFR 1.51.) 

Issued on September 6, 1974. 

James B. Gregory 
Administrator 

39 F.R. 32914 
September 12, 1974 



PART 571; S 123— PRE 6 



MOTOR VEHICLE SAFETY STANDARD NO. 123 
Motorcycle Controls and Displays 

(Docket No. 70-26; Notice 3) 



51. Scope. This standard specifies require- 
ments for the location, operation, identification, 
and illumination of motorcycle controls and dis- 
plays, and requirements for motorcycle stands 
and footrests. 

52. Purpose. The purpose of this standard is 
to minimize accidents caused by operator error 
in responding to the motoring environment, by 
standardizing certain motorcycle controls and 
displays. 

53. Application. This standard applies to 
motorcycles equipped with handlebars, except 
for motorcycles that are designed, and sold ex- 
clusively, for use by law enforcement agencies. 

54. Definitions. "Clockwise" and "counter- 
clockwise" mean opposing directions of rotation 
around following axes, as applicable: 

(a) The operational axis of the ignition con- 
trol, viewed from in front of the ignition lock 
opening; 

(b) The axis of the right handlebar on which 
the twist-grip throttle is located, viewed from 
the end of that handlebar; 

(c) The axis perpendicular to the center of 
the speedometer, viewed from the operator's 
normal eye position. 

55. Requirements. 

55.1 Each motorcycle shall be equipped with 
a supplemental engine stop control, located and 
operable as specified in Table I. 

55.2 Each motorcycle to which this standard 
applies shall meet the following requirements: 

S5.2.1 Control location and operation. If any 

item of equipment listed in Table 1, Column 1, 
is provided, the control for such item shall be 
located as specified in Column 2, and operable 



as specified in Column 3. Each control located 
on a right handlebar shall be operable by the 
operator's right hand throughout its full range 
without removal of the operator's right hand 
from the throttle. Each control located on a 
left handlebar shall be operable by the operator's 
left hand throughout its full range without re- 
moval of the operator's left hand from the hand- 
grip. If a motorcycle with an automatic clutch 
is equipped with a supplemental rear brake con- 
trol, the control shall be located on the left 
handlebar. If a motorcycle is equipped with 
self-proportioning or anti-lock braking devices 
utilizing a single control for front and rear 
brakes, the control shall be located and operable 
in the same manner as a rear brake control. 

55.2.2 Display illumination and operation. If 

an item of equipment listed in Table 2, Column 
1, is provided, the display for such item shall 
be visible to a seated operator under daylight 
conditions, shall illuminate as specified in col- 
umn 2, and shall operate as specified in Column 3. 

55.2.3 Control and display identification. If 

an item of equipment listed in Table 3, Column 
1, is provided, the control for such item shall be 
identified by the word or words shown in Column 
2 and any corresponding word in Column 3, 
placed on or adjacent to the control. 

Control positions shall be identified as speci- 
fied in Column 3, to signify the function per- 
formed at that setting. The abbreviations used 
in Columns 2 and 3 are minimum requirements 
and appropriate words may be spelled in full. 
Identification shall appear to the operator in an 
upright position. 

Functional identification need not be provided 
for equipment items with no entry in Column 3. 



PART 571; S 123-1 



S5.2.4 Stands. A stand shall fold rearward 
and upward if it contacts the ground when the 
motorcycle is moving forward. 



S5.2.5 Footrests. Footrests shall be provided 
for each designated seating position. Each foot- 
rest for a passenger other than an operator shall 
fold rearward and upward when not in use. 



Table 1.— Motorcycle Control Location and Operation Requirements 



Equipment Control 



Location 



Operation 



Column 1 

1. Manual clutch or integrated 
clutch and gear change 

2. Foot operated gear change 



3. Headlamp upper-lower beam 



4. Horn 

5. Turn signal lamps 

6. Ignition 

7. Manual fuel shutoff control 

8. Twist-grip throttle 

9. Supplemental engine stop 
10. Front wheel brake 

IL Rear wheel brakes 



Column 2 
Left handlebar 

Left foot control 



Left handlebar 



Left handlebar 
Handlebars 



Right handlebar 

Right handlebar 
Right handlebar 
Right foot control ' 
Left handlebar per- 
missible for motor- 
driven cycles. 



Column 3 
Squeeze to disengage clutch. 

An upward motion of the operator's toe shift trans- 
mission toward lower numerical gear ratios (commonly 
referred to as "higher gears"), and a downward 
motion toward higher numerical gear ratios (common- 
ly referred to as "lower gears"). If three or more 
gears are provided it shall not be possible to shift 
from the highest gear directly to the lowest gear, 
or vice versa. 

Up for upper beam, down for lower beam. If combined 
with the headlight on-off switch, means shall be 
provided to prevent inadvertent actuation of the 
"off" function. 

Push to activate. 

"Off— counterclockwise from other positions. 
"Off-control forward, "On"-control downward, "Re- 
serve" (if provided)-control upward. 

Self-closing to idle in a clockwise direction after release 
of hand. 

Squeeze to engage. 
Depress to engage. 



' See S5.2.1 for requirements for vehicles with a single control for front and rear brakes, and with a supplemental 
rear brake control. 



Table 2.— Motorcycle Display Illumination and Operation Requirements 



Display 


Illumination 


Operation 


Column 1 

1. Speedometer 

2. Neutral indication 


Column 2 
Yes 
Green display lamp 


Column S 

The display is illuminated whenever the headlamp is 

activated. 
The display lamp illuminates when the gear selector 

is in neutral position. 



PART 571; S 123-2 



Table 3.— Motorcycle Control and Display Identification Requirements 



Equipment 


Control and Display 
Identification 


Identification at Appropriate Position of Control 
or Display 


Column 1 


Column 2 


Column S 


1. Ignition 

2. Supplemental engine stop 

3. Manual choke 


Ignition 
Engine stop 
Choke 


Off 
Off, run 


4. Electric starter 




Start' 


5. Headlamp upper-lower beam 
control 


Lights 


Hi, Lo 


6. Horn 


Horn 




7. Turn signal 

8. Speedometer 

9. Neutral indicator 


Turn 
M.P.H. 

Neutral 


L,R 
M.P.H. increase in a clockwise direction. Major grad- 
uations and numerals appear at 10 mph intervals, mi- 
nor graduations at the 5 mph intervals. (37 F.R. 
17474-August 29, 1972. Effective: 9/1/74) 


10. Upper beam indicator 

11. Tachometer 


High beam 
R.P.M. 




12. Fuel tank shutoff valve 


Fuel 


Off, on, res. 



'Required only if electric starter is separate from ignition switch. 



37 F.R. 7207 
April 12, 1972 



PART 571; S 123-3 



Effective: September 1, 1973 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 124 

Accelerator Control Systems 

(Docket No. 69-20; Notice 3) 



The purpose of this notice is to establish a 
new motor vehicle safety standard that specifies 
requirements for accelerator control systems of 
passenger cars, multi-purpose passenger vehicles, 
trucks and buses. 

A notice of proposed rulemaking on this sub- 
ject was published September 30, 1970 (35 F.R. 
15241). The majority of comments received 
supported the proposal. There were some objec- 
tions and questions, which have been considered 
in formulating the final rule. 

In the previous notice, the Administrator in- 
dicated the importance of this standard in re- 
ducing the number of accidents caused by 
runaway engines. Since 1966, sixty recall cam- 
paigns totalling over 2.9 million vehicles have 
involved this problem. Three percent of all 
complaints in the Administration's files have 
reported malfunctioning accelerator or carbure- 
tor systems. Because the ability of a driver to 
control his vehicle is directly related to the 
proper functioning of the accelerator control 
system, it is essential that this system perform 
as expected, especially when the driver removes 
the actuating force. Therefore, the standard 
sets requirements to ensure the reliability of 
accelerator control systems over a wide range of 
driving conditions. Each system must include 
two independent sources of energy (such as 
springs) which shall return the throttle to idle 
upon the removal of the actuating force. In the 
case of breakage or disconnection in the ac- 
celerator system, the throttle shall return to idle 
either at the time of breakage or at the removal 
of the actuating force. 

The latter requirement differs from the NPRM, 
which mandated a return to idle only when the 
actuating force was removed. Industry com- 



ments raised valid objections to this requirement. 
In some cases, if a breakage occurred and the 
system had to keep operating until the driver 
took his foot off the pedal, a complicated system 
of sensors would have to be built into the throttle 
which would activate the redundant energy 
sources precisely at the time of actual removal. 
Such a device would be too expensive for its 
possible safety benefit, since the incidence of 
accidents from engine loss of power are minimal 
when compared with runaway overspeed statis- 
tics. Manufacturers, therefore, have been given 
the option to use either return-to-idle mode. 

Although many comments suggested modifi- 
cation of the temperature range, the ambient 
temperature levels in the NPRM are retained. 
A review of meteorological data indicates that 
these figures conform to possible driving condi- 
tions in various areas of the United States. 

There are four other proposed requirements 
in the NPRM that are not included in the final 
rule. These are the 300-pound force requirement, 
the coverage of automatic speed control systems, 
the freedom-of-movement requirement, and the 
coverage of motorcycles. 

Several commenters raised objections to the 
300-pound overforce, and some asked for a lesser 
force than 300 pounds. It was found on review 
.;hat the safety benefits of an overforce test has 
not been demonstrated sufficiently and the re- 
quirement has been dropped from the rule. 

The rule does not contain requirements for 
automatic speed control devices. It was found 
that although nine recall campaigns involving 
61,176 vehicles have concerned these devices, no 
relationship to accelerator overspeed accidents 
could be established from automatic speed con- 
trols. Of the 540 multi-disciplinary accident 



PART 571; S 124— PRE 1 



Eff*div«: S«pt*mb*r 1, 1973 



reports that were studied in formulating the 
final rule, none mentioned the automatic system. 
The requirements of the NPRM reiterated SAE 
recommendations that are already used by manu- 
facturers. 

The "freedom-of-movement" paragraph raised 
the objections of subjectivity and difficulty of 
implementation. Enforcement through compli- 
ance testing would lead to controversy over the 
imprecise meaning of "necessary chafing." It 
appears that to comply with the final rule, the 
accelerator system will have to be free of exces- 
sive and unsafe rubbing and friction. 

The decision to eliminate motorcycles from the 
applicability of this standard is based on the 
fact that motorcycles are so different in design 
from the other vehicles covered that definitions 
and failure modes are dissimilar. Also, a safety 
standard specifically tailored for motorcycle con- 
trols (Docket 70-26) will be issued this year. 

This issue of the Federal Register contains a 
Notice of Proposed Rule-making to amend 
Standard No. 124 (37 F.R. 7108). The proposal 
is that the two independent sources of energy 
would return the throttle idle within one half 
second after the removal of the actuating force 
or a breakage or disconnection in the accelerator 
control system. 

This standard is directed at the hazard caused 
by a failure in the accelerator control system. 



Those engine overspeed incidents caused by 
other failure modes such as broken or worn en- 
gine mounts are not addressed by this rulemak- 
ing action. The NHTSA is presently developing 
performance requirements for safety under other 
failure modes. 

In consideration of the foregoing, Part 571 of 
Title 49, Code of Federal Regulations, is 
amended by adding a new § 571.124, Motor Ve- 
hicle Safety Standard No. 124, as set forth 
below. 

Effective Date: September 1, 1973. 

Because of the development work and prepara- 
tion for production that this standard will re- 
quire, it is found that an effective date later 
than 1 year from the date of issuance is in the 
public interest. Accordingly, the standard is 
effective September 1, 1973. 

This rule is issued under the authority of 
Sections 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act (15 U.S.C. 1392, 1407) 
and the delegation of authority at 49 CFR 1.51. 

Issued on March 31, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 7097 
April 8, 1972 



PART 571; S 124^PRE 2 



EffMtiva: S«pl*mb«r 1, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 124 

Accelerator Control Systems 

(Docket No. 69>-20;Notice 5) 



The purpose of this notice is to respond to 
petitions for reconsideration of Motor Vehicle 
Safety Standard No. 124 (49 C.F.R. 571.124), 
and to amend the standard to specify time re- 
quirements for the return of a vehicle's throttle 
to the idle position. 

On April 8, 1972 (37 F.R. 7097), Motor Ve- 
hicle Safety Standard No. 124 was published, 
establishing requirements for accelerator control 
systems, effective September 1, 1973. Simul- 
taneously, a notice was published (37 F.R. 7108) 
proposing that when the driver removes the 
actuating force from the accelerator control or 
in the event of a breakage or disconnection in 
the accelerator control system, the return to idle 
position shall occur within one-half second. 

I. Pursuant to 49 C.F.R. 553.35, petitions for 
reconsideration of the rule were filed by Alfa 
Romeo, American Automobile Association 
(AAA), American Motors Corporation, Chrysler 
Corporation, Diamond Reo Trucks, Incorporated, 
Ford Motor Company, General Motors Corpora- 
tion (GM), International Harvester Company, 
Japan Automobile Manufacturers Association 
(JA^IA), Jeep Corporation, Jesse R. Hollins, 
Mack Trucks, Incorporated, MacMillan Engi- 
neering Lab, Motor Vehicle Manufacturers As- 
sociation of the United States, Incorporated, 
(MVMA) (formerly Automobile Manufacturers 
Association, Incorporated), and Rolls-Royce 
Motors Limited. 

Favorable consideration has been granted to 
some of these petitions, and accordingly, the 
standard is being amended in some minor re- 
spects. The Administrator has declined to grant 
requested relief from other requirements of the 
standard. 



GM and Ford requested that vehicles over 
10,000 pounds GVTVR be exempted from the 
standard, while Mack and Diamond Reo re- 
quested an exemption for vehicles of 26,000 and 
25,000 pounds or more GVWR, respectively. 
Petitioners argued that since these vehicles are 
driven by professionally trained drivers, are 
equipped with engine governors, have a horse- 
power to weight ratio that does not mandate a 
fail-safe requirement, and have not been the sub- 
ject of a defect notification campaign, there is no 
need for the rule's applicability. 

The NHTSA denies petitioners' request. 
Available information shows that accidents re- 
sulting from throttle failure do not occur only 
among the less experienced drivers, nor are they 
diminished by the presence of engine governors 
or by changes in the horsepower to weight ratio. 
Further, these vehicles have been the subject of 
defect notification campaigns, and accident re- 
ports submitted to the Bureau of Motor Carrier 
Safety disclose that an average of two accidents 
occur per month in which the cause is attributed 
to "overspeed incidents"', indicating the type of 
failure the standard is designed to eliminate. 

Additionally, GM stated that the standard's 
test requirements are not justified by the possible 
additional safety benefit that may accrue. They 
argued that the only method by which it could 
assure compliance is by immersion of the entire 
vehicle in a low temperature cell. GM stated 
that sufficient facilities to conduct such tests on 
all their vehicles are not available, and even if 
they were, the test burden is impracticable be- 
cause of the complications of determining where 
over the length of the vehicle the ambient tem- 
perature measurements should be taken. 



PART 571; S 124— PRE 3 



Effective: September 1, 1973 



The NHTSA does not view Standard No. 124 
as a qualification procedure by which a manu- 
facturer can assure himself or his customers that 
the vehicle now has a fail-safe system. The rule 
is intended to provide a minimum i^erformance 
requirement, and does not mandate that assur- 
ances of being in compliance must be made by 
immersing the total vehicle in a low temjjerature 
cell. Assurances of compliance may come from 
other procedures. 

Several petitioners provided data showing that 
it is a common practice in the automobile in- 
dustry to include the "throttle lever"' or "actuat- 
ing lever" as part of the carburetor. They ask 
that these devices be interpreted to be part of the 
fuel metering device so as to afford them greater 
freedom of design. 

The NHTSA agrees with this interpretation. 
The "throttle lever'' or "actuating lever"' as de- 
scribed by the petitioners is a component of the 
fuel metering device. 

Additionally, several petitioners requested that 
the definition of "idle position" be amended to 
take into consideration delay units or "dash pots"" 
which are frequently used on idle settings to 
slow the return of the throttle during its last few 
degrees of rotation to prevent stalling and exces- 
sive exhaust emissions. In essence, petitioners 
request that the return to idle time be measured 
to the point at which the throttle first comes in 
contact with the delay unit or "dash pot.'" This 
request is in accordance with the intended mean- 
ing of the standard. For clarification, the 
NHTSA is amending the definition of "idle po- 
sition" to be the specific point of throttle closure 
at which the throttle first comes in contact with 
an engine idle speed control device. 

Mack and Alfa Romeo petitioned that "liand 
throttles"' and throttle positioners be specifically 
excluded from the definition of "idle position". 
Petitioners stated that in the event such a device 
is used a return to the preset throttle position 
occurs upon release of the driver-operated ac- 
celerator control system. This request is granted. 
If a driver chooses to raise the lowest engine 
speed tlireshold by the use of a throttle position- 
ing device, the throttle should return to that new 
position within the same time requirements speci- 
fied in section S5.3. Accordingly, the NHTSA 



is amending the definition of "idle position" to 
provide for the use of throttle positioners. 

JAMA requested that the engine warm-up 
provisions for cold temperatures be clarified, so 
that it would be possible to conduct tests "after 
warming up the engine according to the manu- 
facturer's recommendation." Standard No. 124 
is silent as to engine warm-up, and states only 
"when the engine is running" as a condition for 
the test. Although the advantages of following 
the manufacturer"s warm-up procedures are rec- 
ognized, it is felt that in most instances the driv- 
ing i^ublic does not adhere to those recommenda- 
tions. Therefore, to afford the driving public as 
brpad a coverage of the rule as is possible, 
JAMA's petition is denied. 

AAA and Chrysler {petitioned for an amend- 
ment of the ambient temperature range. AAA 
urged that since colder temperatures are com- 
monplace in Alaska and that hotter temperatures 
are used by vehicle manufacturers to test fuel 
system control devices, a more severe temperature 
range should be established. Chrysler stated 
that the minus 40 degree figure exceeds automo- 
tive practice by 30 degrees and asked that a 
performance level of minus 10 degrees be estab- 
lished. 

In determining the temperature limits to be 
used, the NHTSA attempted to provide motor 
vehicle safety without establishing impracticable 
desien goals. "Weather data discloses that al- 
though temperatures of minus 40 degrees Fah- 
renheit are encountered in many parts of the 
United States, colder temperatures are unusual. 
For this reason, minus 40 degrees Fahrenheit 
was determined to be the lowest temiserature 
consistent with the needs of motor vehicle safety. 
Conversely, vehicle operations in temperatures 
exceeding 125 degrees Fahrenheit are also un- 

CD O 

usual. Accordingly, it was determined that tem- 
perature limits of minus 40 degrees to plus 125 
degrees Fahrenheit will allow for most climatic 
conditions encountered in the United States. 
The petitions are therefore denied. 

Several petitioners asked for an interpretation 
of the phrase "The system shall include at least 
two sources of energy"' in section S5.1 and 
whether it includes energy sources attached to 
tlie fuel metering service. Petitioners stated 



PART 571; S 124— PRE 4 



Ell«etlv«: S«pl«mb«r 1, 1973 



that a strict interpretation would cause excessive 
design restrictions. If a return spring attached 
to the fuel metering device is capable of return- 
ing the throttle to its idle position after the fail- 
ure of other energj' sources, it meets the intent 
of the standard and should not be disallowed. 
Accordingly, paragraph S5.1 is amended by re- 
placing the phrase "The system shall include at 
least two sources of energy" with "There shall 
be at least two sources of energy". 

JAMA asked whether, if a system includes 
three or more springs, each spring must be inde- 
pendently capable of returning the throttle to 
the idle position. They argued that a system 
could still remain adequately fail-safe as long 
as the other springs operating together can meet 
the requirements. The intent of paragraph S5.1 
is to eliminate the driver's dependence on a 
single accelerator return spring. The NHTSA 
concurs with JAMA's comments and is amending 
paragraph S5.1 to make it clear that independent 
capability of return springs is not required if 
remaining energy sources are collectively capable 
of returning the throttle to the idle position. 

The standard as issued required that the throt- 
tle return to the idle position "whenever any 
element of the accelerator control system becomes 
disconnected or broken." Several petitioners 
seek an interpretation of this wording. GM 
suggested that a disconnection or breakage within 
the driver-operated accelerator control system 
was the only failure mode addressed by the 
standard. Ford asked whether the requirement 
was intended to cover failures caused by bending, 
twisting, jamming, or introduction of foreign 
matter. The NHTSA's intent is to assure safety 
under conditions of a single failure due only to 
a severing or disconnection in the accelerator 
control syatem. To clarify this interpretation, 
the NHTSA is changing the word "breakage" 
to "severance" in paragraph Si, and the word 
"broken" to "severed" in the first sentence of 
paragraph S5.2. Further, the phrase "whenever 
any element of the accelerator control system" 
is changed to "whenever any one component of 
the accelerator control system" for purposes of 
clarification. 

Ford and JAMA petitioned that the effective 
date of the standard be delayed one year. Peti- 



tioners stated that additional time was necessary 
to allow for the creation and confirmation of 
design changes and to resolve any conflicts with 
emission control requirements. 

The NHTSA considers the complexity of the 
requirements of standard No. 124 to be minimal 
and has granted relief on several issues effecting 
design time, and therefore sees no justification 
for delaying the effective date of the standard. 
The petitions are denied. 

II. On April 8, 1972 (37 F.R. 7108) a notice 
was published proposing that when the driver 
removes the actuating force from the accelerator 
control or in the event of a breakage or discon- 
nection in the accelerator control system, the re- 
turn to idle position shall occur within one-half 
second. Available information indicates that in 
most instances the time for driver reaction from 
the accelerator control pedal to the brake is ap- 
proximately one-half second, and this time was 
chosen for the proposal. In response to the 
notice, many commentors objected to the one-half 
second proposal and stated that it did not ade- 
quately take into consideration the viscous nature 
of lubricants in extremely cold temperatures and 
the impracticability of this time requirement for 
the very large systems in heavy trucks and buses. 
The NHTSA recognizes the validity of these ob- 
jections, and allowances have accordingly been 
made for extreme low temperature. An idle 
time of 3 seconds is established for any vehicle 
tested or conditioned in ambient air of degrees 
Fahrenheit or colder. 

Large systems, similar to those used on rear- 
engine buses, have sufficient mass and friction to 
preclude the possibility of compliance with the 
one-half second proposal, unless very high spring 
forces, which would require large changes in 
pedal forces, are used. Several commentators 
stated that tests for conformity with the pro- 
posed requirements show that compliance would 
be possible if the maximum time were extended 
to 2 seconds. The NHTSA finds these comments 
to have merit, and 2 seconds is established as the 
maximum return time for vehicles with a GVWR 
over 10,000 poimds. 

Many comments pertaining to passenger car 
systems stated that the one-half second proposed 
is too severe a requirement. One commentor 



PART 671; S 124— PRE 5 



Effective: September 1, 1973 

stated that extra time will be required if one of 
the return energy sources fails. It was pointed 
out that precedent for an extra allowance can 
be found in the dual braking system requirement, 
which allows added distance for stopping when 
half the system has failed. The accelerator 
standard, however, does not deal with a mech- 
anism with the same redundancy as the braking 
system and it is felt that the maximum time 
selected should allow for the possibility of one 
energy source failing. 

There are a large number of models and engine 
sizes in the passenger car industry, and a large 
number of variety of accelerator control systems 
are designed and built each year. One com- 
mentor suggested that "... a one second time 
limit would considerably increase design op- 
tions . . ." and "presently accepted pedal feel can 
be retained. . . ." Accordingly, one second has 
been decided upon as having the qualities of 
providing a reasonable maximum time for com- 
pliance testing of vehicles of 10,000 pounds or 
less GVWR at temperatures above degrees 
Fahrenheit. 



In response to questions raised by several pe- 
titioners, "ambient temperature is defined as the 
surrounding air temjDerature, at a distance such 
that it is not significantly affected by heat from 
the vehicle under test. The definition contrasts 
the ambient temperature, intended to simulate a 
general outdoor temperature, from temperatures 
imder the hood or otherwise in close proximity 
to the vehicle. 

In consideration of the foregoing, 49 CFE 
571.124, Motor Vehicle Safety Standard No. 124, 
is revised to read as set forth below. 

Effective date : September 1, 1973. 

This rule is issued under the authority of sec- 
tions 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act (15 U.S.C. 1392, 1407) 
and the delegation of authority at 49 CFR 1.51. 

Issued on September 20, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 20033 
September 23, 1972 



PART 571; S 124— PRE 6 



EffacHv*: Seplembsr I, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 124 

Accelerator Control Systems 
(Docket No. 69-20; Notire 6) 



The purpose of this notice is to respond to 
petitions for rulemaking to amend and petitions 
for reconsideration of Motor Vehicle Safety 
Standard No. 124 (49 CFR 571.124). 

On September 23, 1972 (37 F.R. 20033), Motor 
Vehicle Safety Standard No. 124 was published 
specifying time requirements for the return of a 
vehicle's throttle to the idle position. Pursuant 
to 49 CFR 553.35, petitions for reconsideration 
were filed by Japan Automobile Manufacturers 
Association, Inc. (JAMA) and Volkswagen of 
America, Inc. Additionally, pursuant to 49 CFR 
553.31, a petition for rulemaking to amend the 
standard was filed by the Ford Motor Company. 

Favorable consideration has been granted to 
some of the requests and accordingly, the stand- 
ard is being amended in some minor respects. 
The Administrator has declined to grant re- 
quested relief from other requirements of the 
standard. 

Volkswagen requested that the test require- 
ments for cold temperatures be clarified, in order 
to determine whether it is possible to use supple- 
mentary starting devices and to "pump" the ac- 
celerator control pedal during and after the 
presoak and prior to the test. The advantages 
of using supplementary devices and warmup pro- 
cedures are recognized, but in many instances, 
the driving public either does not adhere to the 
manufacturer's recommended warmup procedures 
or uses other procedures. The intent of the stand- 
ard is to afford the driving public as broad a 
coverage of the rule as is possible, by simulating 
as closely as possible actual conditions. Accord- 
ingly, for purposes of testing compliance the 
engine may be started by the use of any supple- 
mentary starting devices and procedures except 
those which would induce the vehicle into mo- 
tion by the application of an external force. 



Volkswagen also asked the NHTSA to define 
the speed at which the accelerator pedal is "to be 
released" to mark the beginning of the test 
determining the return of the throttle to idle 
position. The agency's intent is to provide pro- 
tection in the variety of situations that may be 
encountered on the road. The vehicle, therefore, 
must be capable of meeting the requirements no 
matter. how rapidly or slowly the driver's foot 
is lifted from the pedal. The actuating force 
actually is not "removed'' from the pedal until 
the foot is no longer in contact with it, so the 
measured time period for throttle return does 
not begin until the instant when the foot leaves 
the pedal. 

Further, Volkswagen asked the NHTSA to de- 
fine a "running engine." Volkswagen stated 
that during cold testing an engine could start, 
run for approximately 6 seconds, and then stall. 
Volkswagen theorized that it would be possible to 
have an accelerator system fail the test require- 
ments during this 6-second interval, although the 
engine would be incapable of causing a safety 
problem. The phrase "engine running" defines 
a condition without which throttle return to idle 
position has no significance. The intent of the 
standard is to prevent any safety problems 
caused by faulty throttle return over a broad 
range of operating circumstances and tempera- 
ture conditions. The condition of a running en- 
gine, regardless of torque produced, is a clearly 
definable point at which a safety problem could 
begin to occur. Therefore, the vehicle must be 
capable of meeting the requirements whenever 
the engine is rotating without the application of 
any external force. 

JAMA requested that the time requirements 
for maximum return to idle position when tested 
in temperatures between and minus 40 degrees 



PART 571; S 124— PRE 7 



EffacHva: September 1, 1973 



Fahrenheit be applied "only when there is no 
failure of the source of energy and no disconne<?- 
tion or severance of components." JAMA stated 
that in order for a system to meet the time re- 
quirements of the rule during cold testing, the 
"required pedal effort would be increased to an 
extent that would not be acceptable to the or- 
dinary driver." In its earlier comments to Notice 
3, (37 F.R. 7097), JAMA stated that if each 
energy source was independently required to re- 
turn the throttle to idle within the specified time 
requirements, increased pedal forces would be 
necessary. In response to this comment and to 
allow a manufacturer design freedom, the stand- 
ard was amended by Notice 5, (37 F.R. 20033), 
to specify that independent capability of energy 
sources to return the throttle to idle position was 
not required. The amendment also gave an addi- 
tional time allowance for return to idle position 
for vehicles tested or conditioned in cold tem- 
peratures. Based on these factors and on the 
comments received from other manufacturers, this 
agency's position is that the standard provides 
enough latitude for a manufacturer to feasibly 
meet the pedal force requirements and the time re- 
quirements for return to idle, even if there is a 
failure of one source of energy or a severance or 
disconnection occurs. The petition is therefore 
denied. 

Ford pointed out that under the requirements 
section, S5.1 states that, "There shall be at least 
two sources of energy" and that this seemed at 
variance with the intent expressed in the pre- 
amble to Notice 5 that energy sources do not have 
to be contained in the accelerator control system. 
To further clarify the intent expressed in Notice 
5, the phrase in S.5 "The vehicle shall be equipped 



with a driver-operated accelerator control system 
that meets the following requirements" is changed 
to "The vehicle shall meet the following re- 
quirements . . . ." 

Ford also asked for a clarification of the word 
"failure" in So.l. Ford stated that the word 
was ambiguous in that it would allow for ab- 
normal operating conditions outside the scope 
of the standard's intent to assure safety under 
conditions of a single failure due to a severance 
or disconnection in the system. To clarify the 
standard's intent, the phrase in S5.1 which states 
that, "In the event of failure of one source of 
energy the remaining source or sources shall be 
capable of returning the throttle" is changed to 
"In the event of failure of one source of energy 
by a single severance or disconnection, the throttle 
shall return . . . ." 

Further, in the first sentence of S5.2 the word 
"becomes" is changed to "is" and the phrase "at 
a single point" is added to the end of the sentence 
to clarify this meaning. 

In consideration of the foregoing, 49 CFR 
571.124, Motor Vehicle Safety Standard No. 124, 
is revised to read as set forth below. 

Effective date: September 1, 1973. 

(Sec. 103, 119, Pub. L. 89-563, 80 Stat. 718, 15 
U.S.C. 1392, 1407 ; delegation of authority at 49 
CFR 1.51.) 

Issued on January 24, 1973. 

Douglas W. Toms 
Administrator 

38 F.R. 2980 
January 31, 1973 



PART 571; S 124— PRE 8 



MOTOR VEHICLE SAFETY STANDARD NO. 124 
ACCELERATOR CONTROL SYSTEMS 



(Docket No. 69-20; Notice 3) 



51. Scope. This standard establishes require- 
ments for the return of a vehicle's throttle to the 
idle position when the driver removes the ac- 
tuating force from the accelerator control, or in 
the event of a severance or disconnection in the 
accelerator control system. 

52. Purpose. The purpose of this standard is 
to reduce deaths and injuries resulting from 
engine overspeed caused by malfunctions in the 
accelerator control system. 

53. Application. This standard applies to 
passenger cars, multipurpose passenger vehicles, 
trucks, and buses. 

54. Definitions. 

S4.1 "Driver-operated accelerator control sys- 
tem" means all vehicle components, except the 
fuel metering de\nce, that regulate engine speed 
in direct response to movement of the driver- 
operated control and that return the throttle to 
the idle position upon release of the actuating 
force. 

"Fuel metering device" means the carburetor, 
or in the case of certain engines, the fuel in- 
jector, fuel distributor, or fuel injection pump. 

"Throttle" means the component of the fuel 
metering device that connects to the driver- 
operated accelerator control system and that by 
input from the driver-operated accelerator con- 
trol system controls the engine speed. 

"Idle position" means the position of the 
throttle at which it first comes in contact with 
an engine idle speed control appropriate for 
existing conditions according to the manufac- 
turer's recommendations. These conditions in- 
clude, but are not limited to, engine speed 



adjustments for cold engine, air conditioning, 
and emission control, and the use of throttle 
setting devices. 

"Ambient temperature" means the surround- 
ing air temperature, at a distance such that it is 
not significantly affected by heat from the ve- 
hicle under test. 

S4.2 In the case of vehicles powered by elec- 
tric motors, the word "throttle" and "idle" refer 
to the motor speed controller and motor shut- 
down, respectively. 



S5. Requirements. The vehicle shall meet the 
following requirements when the engine is run- 
ning under any load condition, and at any am- 
bient temperature between minus 40° Fahrenheit 
and plus 125° Fahrenheit after 12 hours of con- 
ditioning at any temperature within that range. 

55.1 There shall be at least two sources of 
energy capable of returning the throttle to the 
idle position within the time limit specified by 
S5.3 from any accelerator position or speed when- 
ever the driver removes the opposing actuating 
force. In the event of failure of one source of 
energy by a single severance or disconnection, 
the throttle shall return to the idle position 
within the time limits specified by S5.3, from 
any accelerator position or speed whenever the 
driver removes the opposing actuating force. 

55.2 The throttle shall return to the idle po- 
sition from any accelerator position or any speed 
of which the engine is capable whenever any one 
component of the accelerator control system is 
disconnected or severed at a single point. The 



PART 571; S 124-1 



return to idle shall occur within the time limit 2 seconds for vehicles of more than 10,000 pounds 

specified by S5.3, measured either from the time GVWR. Maximum time to return to idle posi- 

of severance or disconnection or from the first tion shall be 3 seconds for any vehicle that is 

removal of the opposing actuating force by the exposed to ambient air at to minus 40 degrees 

driver. Fahrenheit during the test or for any portion of 

S5.3 Except as provided below, maximum the 12-hour conditioning period, 

time to return to idle position shall be 1 second 37 F.R. 7097 

for vehicles of 10,000 pounds or less GVWR, and April 8, 1972 



PART 571; S 124-2 



Eff*ctiv«: January 1, 1974 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 125 

Warning Devices 



The purpose of this amendment to Part 571 
of Title 49, Code of Federal Regiilations, is to 
add a new Motor Vehicle Safety Standard No. 
125 (49 CFR §571.125) that would establish 
shape, size, and performance requirements for 
warning devices that do not have self-contained 
energy sources. The devices are carried in motor 
vehicles and are erected to alert approaching 
motorists to the presence of a disabled vehicle. 

A notice of proposed rulemaking on this sub- 
ject was published on November 11, 1970 (36 
F.R. 17350). The comments received in response 
to the notice have been considered in this issu- 
ance of a final rule. 

As noted in the proposed rule, the standard 
will supplement the vehicular hazard warning 
signal lamps required by F.M.V.S.S. No. 108, 
Lamps, Refective Devices, and Associated Equip- 
ment, in minimizing the likelihood of rear end 
collisions between oncoming traffic and disabled 
vehicles. 

The standard is issued as an equipment stand- 
ard and establishes requirements only for warn- 
ing devices which do not have self-contained 
energy sources. Because provision of warning 
devices in new vehicles is optional, the instruc- 
tions regarding the number of devices to be used 
are recommendations, rather than requirements, 
and the storage location requirement is deleted. 

The standard requires that the device be bi- 
directional, lowers the minimum length of the 
triangle legs, and increases the permissible devi- 
ation from a vertical plane for the triangle when 
the device is placed on the road. It reduces the 
required minimum candlepower of the red reflec- 
tive material and raises the luminance require- 
ment for the orange fluorescent material. It also 
adds definitions of "reflex reflective," deletes one 
of the two definitions of the colors "red" and 
"orange," and deletes one of the two reflectivity 



requirements. With respect to the conditioning 
requirements, the standard lowers the high tem- 
perature requirement. 

Several of the comments submitted by foreign 
motor vehicle manufacturers stated that the 
warning device should conform to the recom- 
mendations of international advisory groups. 
The Economic Commission of Europe (E.C.E.), 
a United Nations-sponsored council of which 
twenty-six nations, including the United States, 
are members, is in the process of developing 
specifications for warning triangles to be ratified 
by national governments. The NHTSA has 
adopted most of the proposed E.C.E. require- 
ments with the exception of the minimum 
candlepower requirement for wide angle posi- 
tioning of the device. The NHTSA has deter- 
mined that a lower minimum candlepower than 
that required by the E.C.E. provides adequate 
protection and is a more realistic reflection of 
the state of the art. 

Comments from the domestic automobile in- 
dustry objecting to mandatory provision of 
warning devices stated that available informa- 
tion does not justify the additional cost of sup- 
plying them in new vehicles. The NHTSA has 
concluded that it is necessary to collect further 
data regarding efi'ectiveness of warning devices 
and frequ^cy of use by consumers so that more 
accurate cost-benefit analyses may be made. For 
these reasons, the provision of warning devices 
has been made optional by issuing an equipment 
standard. 

Numerous manufacturers of fusees submitted 
comments which described the merits of fusees 
and concluded that the proposed rule would pro- 
hibit the use of fusees. Neither the rule as issued 
nor the proposed rule applies to devices which 
have a self-contained energy source, such as 
fusees, flare pots, and electric lanterns. Thus 



PART 571; S 125— PRE 1 



Effective: January 1, 1974 



these devices may continue to be used as an 
alternative or a supplement to the device de- 
scribed in the standard. 

Numerous comments from private citizens and 
State officials expressed concern that the required 
triangular shape of the warning device •would 
prohibit the triangular Slow Moving Vehicle 
emblem currently used on many motor vehicles. 
Other comments supported the use of the tri- 
angular device because the triangular shapes 
would be used for similar purposes, to alert 
oncoming traffic that a reduction of speed is 
necessary due to a vehicle ahead. The Admin- 
istration supports the dual use of the triangular 
symbol and it is intended that the warning de- 
vice and the Slow Moving Vehicle emblem be 
complementary. As discussed in the notice of 
proposed rulemaking. State laws regarding slow 
moving vehicle emblems would be preempted by 
the standard only to the extent that they forbid 
the use of the triangular warning device intended 
by the standard. 

Many comments recommended that the warn- 
ing device be bi-directional in order to eliminate 
the possibility of placing the warning device 
with the non-reflective side facing oncoming 
traffic. It was pointed out that the increased 
cost of a bi-directional device over a unidirec- 
tional device would be minimal relative to the 
safety benefits provided. The XHTSA agrees, 
and accordingly the standard as issued requires 
the device to be bi-directional. 

Some commenters felt that the motorist would 
subject himself to an additional safety hazard 
in placing the device approximately 100 feet be- 
hind the vehicle. Some suggested that the device 
be placed either on top of the vehicle or be cap- 
able of attaching to a window frame. "While it 
is of course true that walking in a roadway can 
be hazardous, in the judgment of the XHTSA 
this risk is outweighed by the safety benefits of 
positioning the device at a distance behind the 
vehicle. Such positioning provides a greater 
distance over which oncoming traffic can recog- 
nize and respond to the warning and thus affords 
greater protection to the disabled vehicle. 

Figures 3 through 9 indicating recommended 
positioning of warning devices have been con- 
solidated into a single diagram indicating the 
suggested placement of the devices. 



The permissible deviation from a vertical 
plane for the triangle when the device is placed 
on the road has been increased from five degrees 
to ten degrees in response to comments from 
manufacturers. The XHTSA has determined 
that the change will not alter the effectiveness 
of the device. The required distance above the 
ground of the lower edge of the triangle has 
been increased from one-half to one inch to im- 
prove the effectiveness of the device when water 
or mud collects on the roadway. 

The minimum length of the legs of the tri- 
angle has been lowered from 18 to 17 inches, to 
correspond to the range of lengths permitted by 
the Bureau of Motor Carrier Safety. 

The minimum width of the red reflective ma- 
terial has bee« clarified at the request of two 
manufacturers of reflex reflectors to correspond 
to industry terminology. 

The definitions of the colors "red" and 
"orange" have been clarified in light of the com- 
ments, by the deletion of the definition in terms 
of nanometers. The XHTSA has concluded 
that definitions in terms of chromaticity coordi- 
nates and purity are sufficient. In order to 
standardize the requirement with respect to cur- 
rent color specification practice, the required 
chromaticity coordinates have been changed 
s'ightly. 

The reflectivity requirement has been clarified 
to state that the material must be reflex reflec- 
tive, and a definition of "reflex reflective" has 
been added to the standard. The reflectivity 
requirement in terms of candlepower per square 
inch has been found to be superfluous, and ac- 
cordingly has been deleted. 

The Economic Commission of Europe re- 
quested that the required total minimum candle- 
power per incident foot candle for an observa- 
tion angle of 0.2 degrees be lowered from 120 
candlepower fo correspond to the international 
specifications. The XHTSA has concluded that 
80 candlepower will provide sufficient protection 
and the minimum candlepower has been lowered 
accordingly. 

In order to standardize the requirement with 
respect to current photometric practice, the 
luminance requirement for orange fluorescent 
material in the warning device has been raised 
from not less than 30 percent to not less than 



PART 571; S 125— PRE 2 



35 percent of that of a flat ma^esium oxide 
surface. The luminance criterion, "when com- 
pared under the light from an overcast sky," has 
been changed to read "when subjected to a 150- 
watt high pressure xenon compact arc lamp." 

Many equipment manufacturers stated that 
the 200 degree Fahrenheit requirement for the 
high temperature conditioning is not justified by 
evidence showing that the device must withstand 
temperatures at that level when in use. This 
contention has been found to have merit, and 
the temperature requirement has been lowered 
to 150 degrees. 

Effective date: January 1, 1974. Because the 
standard is issued later than anticipated, the 
effective date has been extended from January 
1, 1972 to January 1, 1974. The NHTSA has 
concluded that this date will permit manufac- 
turers of warning devices which do not have 
self-contained energy sources and which do not 



Effective: January 1, 1974 

meet the specifications of the standard to retool 
for manufacture of complying devices. It is 
therefore found, for good cause shown, that an 
effective date more than one year from the date 
of issuance is in the public interest. 

In consideration of the above, a new § 571.125, 
Standard No. 125, Warning Devices, is added to 
Title 49, Code of Federal Regulations. . . . 

This rule is issued imder the authority of 
sections 103, 112, and 119 of the National Traffic 
and Motor Vehicle Safety Act (15 U.S.C. 1392, 
1401, 1407) and the delegation of authority at 
49 CFR 1.51. 



Issued on March 1, 1972. 



Charles H. Hartman 
Acting Administrator 

37 F.R. 5038 
March 9, 1972 



PART 571; S 125— PRE 3^ 



Effective: January 1, 1974 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 125 



Warning Devices 
(Docket 4-2; Notice 5) 



The purpose of this notice is to respond to peti- 
tions for reconsideration of Motor Vehicle Safety 
Standard No. 125, Warning Devices, in § 571.125 
of Title 49, Code of Federal Regulations. The 
standard was issued on March 1, 1972 (37 F.R. 
5038). 

The Amerace-Esna Corporation suggested that 
the 98% purity requirement for the red reflex re- 
flective material be deleted since the trichromatic 
color coefficients provide sufficient definition of 
the red color. The NHTSA agrees, and further- 
more has determined that the purity requirement 
for the orange fluorescent material should be de- 
leted for the same reasons. Accordingly, 
S5.3.1(c) and S5.3.2(c) are deleted from the rule. 

Hawes Industries, Inc. requested that the stand- 
ard permit the use of a triangular warning de- 
vice designed to be secured on the roof of a motor 
vehicle. They stated that the roof location was 
more convenient to the consumer than the recom- 
mended positioning behind the car and afforded 
as much or more protection. As stated in the 
preamble to the standard, a number of comments 
advocating positioning of the device on the ve- 
hicle roof or side were received and reviewed by 
the NHTSA in the formulation of the final rule. 
The Administration determined that placement 
of the device behind the vehicle would provide 
maximum protection by affording a greater dis- 
tance for recognition and response by oncoming 
traffic. For this reason, it has recommended posi- 
tioning of the device 100 feet behind the vehicle 
and requires an illustration indicating this loca- 
tion to be provided in the instructions. The 
standard does not prohibit manufacture or sale of 
a device capable of being mounted on a vehicle 
roof, as long as it meets all the Standard 125 re- 
quirements, including the capability of being set 
up on the ground. 



The standard requires that an illustration de- 
picting recommended positioning of the device 
be included with the instructions for the device. 
The Administration is amending S5.1.5(c) to 
clarify its intent that the illustration provided be 
substantially identical to Figure 3. 

The standard as issued establishes separate 
width requirements for red reflex reflective ma- 
terial and orange fluorescent material affixed to 
the faces of the warning device. Rowland De- 
velopment Corporation stated that it manufac- 
tures a "dual purpose fluorescent orange-red 
reflective material," and requested that the sep- 
arate width requirements be suspended when such 
material is used. The request appears to have 
merit, but NHTSA has concluded that an evalua- 
tion of the requirements pertaining to the fluo- 
rescent orange material is necessary before it can 
respond to this request. A notice of proposed 
rulemaking containing proposed changes will be 
issued when the evaluation is completed. When 
the final revised requirements for the fluorescent 
material are established, a precise definition of the 
dual purpose material can be formulated. 

Prof. D. M. Finch of the University of Cali- 
fornia stated that in order to clarify the color re- 
quirements the respective sources of illumination 
for the measurement of the red and orange color 
should be specified. The NHTSA agrees that 
this should be done, and accordingly S5.3.1 has 
been modified to specify the use of a lamp with a 
tungsten filament operating at 2,854° K for the 
red measurement. The source of illumination for 
the measurement of the orange color will be spec- 
ified with the revision of the fluorescent material 
requirements referred to above. 

The word "tungsten" is inserted before the 
word "filament" in the rule, as a clarification of 
the test conditions for red color and reflectivity. 



PART 571; S 125— PRE 5 



EffKtiva: January I, 1974 

In consideration of the foregoing, Motor Ve- 1407) and the delegation of authority at 49 CFR 

hide Safety Standard No. 125, Warning Devices, 1.51. y '±^'^ra 

49 CFR § 571.125, is amended. . . . Issued on June 19, 1972. 

Effective date : January 1, 1974. D^^^j.^ ^ ^^^^ 

This notice is issued under the authority of sec- Administrator 

tions 103, 112, and 119 of the National Traffic and 37 p - .j,,. 

Motor Vehicle Safety Act (15 U.S.C. 1392, 1401, June 22, 1972 



PART 571; S 125— PRE 6 



Effective: January 1, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 125 



Warning Devices 
Docket No. 4-2; Notice 6) 



The purpose of this notice is to respond further 
to petitions for reconsideration and amendment 
of Motor Vehicle Safety Standard No. 125, 
Warning Devices, § 571.125 of Title 49, Code of 
Federal Regulations. The standard was issued 
on March 1, 1972, (.37 F.R. 50.38). On June 22, 
1972, a previous notice of amendments and recon- 
sideration of the standard was published (37 
F.R. 12323). 

With respect to the configuration of the device 
Rowland Development Corporation stated that 
it manufactures a dual purpose fluorescent orange 
and red reflective material and requested that the 
separate width requirements for red reflex re- 
flective material and orange fluorescent material 
affixed to the faces of the device be suspended 
when such material is used. The NHTSA has 
concluded that the use of such dual purpose ma- 
terial as an alternative to separate material is 
permissible if the material is capable of meeting 
the requirements of Standard 125. S5.1.1, S5.2.3, 
S5.5, and S6.2(a) are hereby modified accord- 
ingly, and the separate width requirements will 
not be applicable when dual purpose material is 
used. 

Tri-Lite interpreted the standard as permitting 
the use of a flag as part of a "combination signal 
device" as long as the device did not violate 
S5.2.1(b), relating to obstruction of the reflective 
and fluorescent material. In a previous letter to 
Tri-Lite the XHTSA had stated that the stand- 
ard would be interpreted to allow such additions. 
(Docket entry X4-4-2-10, July 18, 1972.) Upon 
further consideration, the agency has detennined 
that permitting additions to the device will lessen 
its eff'ectiveness by degrading the uniformity of 
its shape. Accordingly, the use of additional 
shapes or attachments will not be permitted, and 
a new S5.2.6 is added to that effect. 



A number of petitions regarding the orange 
fluorescent material were received. Personnel 
from the National Bureau of Standards sug- 
gested that the requirements for the color of the 
orange fluorescent material be amended so as not 
to penalize colors that have the same hue but are 
stronger than the present maximum y and mini- 
mum X values. The NHTSA agrees with the 
suggestion and S5.3.2 has been amended accord- 
ingly- 

Tri-Lite stated that the fluorescent material 
deteriorates over time and is therefore unreliable. 
It requested that the provision of orange fluores- 
cent material on the device be made optional. 
The NHTSA recognizes that deterioration of 
fluorescence is a possibility; however, it is felt 
that the requirement of an opaque container and 
the improving technologj- of fluorescent materials 
should offset the possible problem. It is antici- 
pated that the device will be used only infre- 
quently, in emergencies, by most drivers. The 
request of Tri-Lite is therefore denied. 

Rowland Corp. requested that the luminance 
requirement be expressed in terms relative to the 
amount of fluorescent material affixed to the de- 
vice rather than the percentage figure of mag- 
nesium oxide presently required. The agency 
position is that a minimum level of luminance is 
necessary for identifiability, but that a somewhat 
lower limit for luminance of the orange material 
could be suitable if more material is used. Ac- 
cordingly, So. 5 has been amended to lower the 
minimum relative luminance relative to mag- 
nesium oxide from 35% to 25%, and to require 
a minimum product of that relative luminance 
and width in inches of the device of 44. Dayglo 
Color Corp. requested that two sources of light 
for luminance test, Source C and Source D-65, 
be permitted in addition to the xenon arc lamp 



PART 571; S 125— PRE 7 



Effective: January 1, 1974 



specified in the standard. The NHTSA has con- 
duded that the most consistent test results are 
provided when the material is diffusely irradiated 
with undispersed light from a high-pressure 
xenon arc lamp to simulate daytime conditions. 
As a general rule, alternative test procedures for 
a single property are inadvisable, and no suffi- 
cient justification for them has been shown here. 
Therefore the Dayglo request is denied. 

In light of evidence that differing relative 
luminance values are obtained from different pro- 
cedures used to measure it, a procedures para- 
graph (S6.3) for the luminance testing of the 
orange fluorescent material has been added to 
the standard. The procedure is adapted from 
the publication "Colorimetry", of the Interna- 
tional Commission on Illumination (CIE Pub- 
lication No. 15, E-1.3.1, 1971). 

Two petitions dealt with the stability re- 
quirements. Rowland Development Corporation 
requested that the standard permit the manu- 
facture of a triangle device constructed of flexible 
material which is secured at the outer corners 
of the triangle and is otherwise free to flex with 
the wmd. Safety Triangles Company requested 
that the device be permitted to tilt to a position 
up to 30° from the vertical rather than the pres- 
ently allowed 10°. These requests were directed 
at permitting manufacturers to produce lighter 
and cheaper devices. TheNHTSA has concluded 
that if the triangle is pei-mitted to flex in the 
wind or tilt to a position up to 30° from the 



vertical, the attitude of the triangle is altered so 
that the shape of the equilateral triangle is dis- 
torted, thus detracting from one of the goals of 
the standard. The present performance require- 
ments and the consequent cost factors have been 
found to be reasonable. These requests are ac- 
cordingly denied. 

With respect to reflectivity testing, Rowland 
stated that candlepower requirements for an ob- 
servation angle of 0.2° were superfluous and not 
related to true highway situations, and requested 
their deletion. The NHTSA has determined in 
the formulation of the standard that the speci- 
fied reflectivity requirements allow a maximum 
recognition and detection distance to oncoming 
traffic. Accordingy, the requirements for the 0.2° 
observation angle are retained. 

In consideration of the foregoing, Motor Ve- 
hicle Safety Standard No. 125, Warning Devices, 
49 CFR §571.125, is amended. . . . 

Effective date: January 1, 1974. 

(Sec. 103, 112, 119, Pub. L. 89-563, 80 Stat. 
718, 15 U.S.C. 1392, 1401, 1407; delegation of au- 
thority at 49 CFR 1.51.) 

Issued on January 23, 1973. 

Douglas W. Toms 
Administrator 

38 F.R. 2760 
January 30, 1973 



PART 571; S 125— PRE 8 



Effective: November 11, 1974 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 125 

Warning Devices 
(Docket No. 74-2; Notice 10) 



The purpose of this amendment to Motor Ve- 
hicle Safety Standard No. 125 (49 CFR 571.125), 
Warning Devices, is to prescribe the color specifi- 
cations for the orange and red materials used in 
the warning devices authorized under the stand- 
ard. 

On April 6, 1973, the NHTSA issued a pro- 
posal on this subject (38 F.R. 8752). The com- 
ments from industry were generally in agreement 
with the method for testing the orange fluores- 
cent material, although several requested that 
light source C be allowed for testing of the orange 
fluorescent material. After consultation with 
testing laboratories and the National Bureau of 
Standards, NHTSA has concluded that for pur- 
poses of obtaining repeatable results and simulat- 
ing daylight conditions, source C does not pro- 
vide the necessary ultraviolet radiation. There- 
fore, the use of the xenon arc lamp has been 
incorporated into the standard and will be re- 
quired for testing of the orange color and lumi- 
nescence of the daylight fluorescent material. 

The majority of the commenters and the Na- 
tional Bureau of Standards agreed that the direct 
illumination method for testing of standard 
orange fluorescent material for both color and 
luminance should be continued, and the integrat- 
ing sphere method should be used for dual- 
purpose materials. The industry, including the 
testing laboratories, have had sufficient time to 
utilize this method and repeatable results have 
been obtained. 

The color definition equation for the orange 
fluorescent material has been broadened from 
x-|-y = 0.943 to x-fy = 0.93. The majority of 



those commenting had no objection to broaden- 
ing the area of the orange fluorescent material, 
but one equipment manufacturer desired the red 
boimdary to be extended from y = 0.35 to y = 0.34. 
NHTSA concludes that to do so would place this 
boundary line too near the red area for proper 
differentiation between orange and red. Since 
orange is used as a daylight material, it should 
not be similar to the red material in color. 

As proposed, the three-digit system in the 
straight-line equations for the boundary of the 
orange and red colors has been converted to a 
two-digit system, as this degree of accuracy is 
sufficient for general testing purposes. 

The final amendment to the standard estab- 
lishes the type of light to be used for testing the 
orange material used in dual purpose material. 
Of particular importance in this test procedure 
is separating the red retroreflective and orange 
fluorescent material. The majority of the com- 
menters and the National Bureau of Standards 
recommended that the xenon arc lamp be used, as 
it provides sufficient ultraviolet radiation to simu- 
late daylight conditions with overcast sky, if the 
unmodified spectrum illuminating the material is 
at an angle of incidence of 45° and the angle 
of observation is 90°. In this procedure, which 
is adopted, the material is illuminated diffusely 
by an integrating sphere. 

Because a number of amendments to Standard 
No. 125 have been issued, the standard is hereby 
reissued in its entirety. 

In light of the foregoing, 49 CFR § 571.125, 
Standard No. 125, "Warning Devices, is amended 
to read as set forth below. 



PART 571; S 125— PRE 9 



Effective: November 11, 1974 

Effective date: Nov. 11, 1974. Issued on: Aug. 2, 1974. 

James B. Gregory 
(Sec. 103, 119, Pub. L. 89-563) 80 Stat. 718, Administrator 

15 U.S.C. 1392, 1407; delegation of authority at 39 p.R. 28636 

49 CFR 1.51.) ■ August?, 1974 



I 



PART 571; S 125— PRE 10 



MOTOR VEHICLE SAFETY STANDARD NO. 125 
Warning Devices 



51. Scope. This standard establishes require- 
ments for devices, without self-contained energy 
sources, that are designed to be carried in motor 
vehicles and used to warn approaching traffic 
of the presence of a stopped vehicle, except for 
devices designed to be permanently affixed to the 
vehicle. 

52. Purpose. The purpose of this standard 
is to reduce deaths and injuries due to rear end 
collisions between moving traffic and disabled 
vehicles. 

53. Application. This standard applies to de- 
vices without self-contained energy sources, that 
are designed to be carried in motor vehicles and 
used to warn approaching traffic of the presence 
of a stopped vehicle, except for devices designed 
to be permanently affixed to the vehicle. 

S.4. Definitions. "Entrance angle" means the 
angle having as its sides the line through the 
center, and normal to the face, of the object to 
be tested, and the line from the center of the 
object to the center of the source of illumination 
(Figure 2). 

"Fluorescent" means the property of emitting 
visible light due to the absorption of radiation 
of a shorter wave-length which may be outside 
the visible spectrum. 

"Observation angle" means the angle having 
as its sides the line from the observation point 
to the center of the object to be tested and the 
line from the center of that object to the center 
of the source of illumination (Figure 2). 

"Reflex reflective" means reflective of light in 
directions close to the direction of incident light, 
over a wide range of variations in the direction 
of incident light. 



WARNING DEVICE 



0.25 TO 0.50 RADIUS 



2 TO 3 




RED REFLECTIVE 
MATERIAL 0.75 TO 1.75 



ORANGE FLUORESCENT 
MATERIAL 
25 TO 1-30 



DIMENSIONS OF WARNING DEVICE (Inches) 



Figure 1 

S5. Requirements. 
S5.1 Equipment. 

55.1.1 Reflex reflective material and fluores- 
cent material that meet the requirements of this 
standard shall be affixed to both faces of the 
warning device. Alternatively, a dual purpose 
orange fluorescent and red reflective material that 
meets the requirements of this standard (here- 
after referred to as "dual purpose material") 
may be affixed to both faces in place of the reflec- 
tive and fluorescent materials. 

55.1.2 Each warning device shall be protected 
from damage and deterioration— 

(a) By enclosure in an opaque protective re- 
usable container, except that two or three warn- 



PART 571; S 125-1 



ing devices intended to be sold for use as a set 
with a single vehicle may be enclosed in a single 
container; or 

(b) By secure attachment to any light-tight, 
enclosed and easily accessible compartment of a 
new motor vehicle with which it is supplied by 
the vehicle manufacturer. 

55.1.3 The warning device shall be designed 
to be erected, and replaced in its container, with- 
out the use of tools. 

55.1.4 The warning device shall be perma- 
nently and legibly marked with: 

(a) Name of manufacturer; 

(b) Month and year of manufacture, which 
may be expressed numerically, as "6/72", and 

(c) The symbol DOT, or the statement that 
the warning device complies with all applicable 
Federal motor vehicle safety standards. 

55.1.5 Each warning device shall have in- 
structions for its erection and display. 

a) The instructions shall be either indelibly 
printed on the warning device or attached in 
such a manner that they cannot be easily removed. 

(b) Instructions for each warning device shall 
include a recommendation that the driver activate 
the vehicular hazard warning signal lamps before 
leaving the vehicle to erect the warning device. 

(c) Instructions shall include the illustration 
depicted in Figure 3 indicating recommended 
positioning. 

OBSERVATION POINT 
'4Cr 



IFMONTI (HEAR) 



APPROXIMATELY 40 PACES 



REFLECTED LIGHT 



OBSERVATION 
(DIVERGENCE! ANGLE 



LIGHT 
SOURCE 




INCIDENT LIGHT 

ENTRANCE (INCIDENCEl ANGLE 
PERPENDICULAR TO REFLECTIVE SURFACE 
REFLECTIVE SURFACE 



-100 FT. 



DISABLED ',_— 

VEHITLF I V, 



' WARNING 
-S- DEVICE 



RECOMMENDED WARNING DEVICE POSITIONING 



Figure 3 



REFLECTIVITY TEST DIAGRAM 
Figure 2 



S5.2 Configuration 

55.2.1 When the warning device is erected on 
level ground: 

(a) Part of the warning device shall form an 
equilateral triangle that stands in a plane not 
more than 10° from the vertical, with the lower 
edge of the base of the triangle horizontal and 
not less than 1 inch above the ground. 

(b) None of the required portion of the re- 
flective material and fluorescent material shall 
be obscured by any other part of the warning 
device except for any portion of the material 
over which it is necessary to provide fasteners, 
pivoting beads or other means to allow collapsi- 
bility or support of the device. In any event, 
sufficient reflective and fluorescent material shall 
be used on the triangle to meet the requirements 
of S5.4 and S5.5. 

55.2.2 Each of the three sides of the tri- 
angular portion of the warning device shall not 
be less than 17 and not more than 22 inches long, 
and not less than 2 and not more than 3 inches 
wide (Figure 1). 

55.2.3 Each face of the triangular portion 
of the warning device shall have an outer border 
of red reflex reflective material of uniform width 
and not less than 0.75 and not more than 1.75 
inches wide, and an inner border of orange 
fluorescent material of uniform width and not 
less than 1.25 and not more than 1.30 inches wide 
(Figure 1). However, this requirement shall not 
apply if the dual purpose material is used. 

55.2.4 Each vertex of the triangular portion 
of the warning device shall have a radius of not 
less than 0.25 inch and not more than 0.50 inch. 

55.2.5 All edges shall be rounded or cham- 
fered, as necessary to reduce the possibility of 
cutting or harm to the user. 



PART 571; S 125-2 



S5.2.6 The device shall consist entirely of the 
triangular portion and attachments necessary 
for its support and enclosure, without additional 
visible shapes of attachments. 





























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400 


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100 


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GREtM 


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CL.RPLE 


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Figure 4 - CIE Chromatic it|p OiSBrim 



S5.3 Color. 



55.3.1 The color of the red reflex reflective 
material on the warning device shall have the 
following characteristics, both before and after 
the warning device has been conditioned in ac- 
cordance with S6.1, when the source of illumina- 
tion is a lamp with a tungsten filament operating 
at 2856° Kelvin color temperature. Expressed 
in terms of the International Commission on 
Illumination (CIE) 1931 standard colorimetric 
observer system (CIE chromaticity diagram, 
Figure 4), the chromaticity coordinates of the 
red reflex reflective material shall lie within the 
region bounded by the spectrum locus and the 
lines on the diagram defined by the following 
equations: 

Boundary Equations 

Yellow y = 0.33 

White x-t-y = 0.98 

55.3.2 The color of the orange fluorescent 
material on the warning device shall have the 
following characteristics, both before and after 
the warning device has been conditioned in ac- 
cordance with S6.1, when the source of illumina- 



tion is a 150-watt high pressure xenon compact 
arc lamp. Expressed in terms of the Interna- 
tional Commission on Illumination (CIE) 1931 
standard colorimetric observer system, the chro- 
maticity coordinates of the orange fluorescent 
material shall lie within the region bounded by 
the spectrum locus and the lines on the diagram 
defined by the following equations: 

Boundary Equation 

Yellow y = 0.49x-(-0.17 

White x-(-y = 0.93 

Red y = 0.35 

The 150-watt high pressure xenon compact arc 
lamp shall illuminate the sample using the un- 
modified spectrum at an angle of incidence of 45° 
and an angle of observation of 90°. If dual 
purpose material is being tested, it shall be illum- 
inated by a 150-watt high pressure xenon com- 
pact arc lamp, whose light is diffused by an 
integrating sphere. 

55.4 Reflectivity. When the red reflex reflec- 
tive material on the warning device is tested in 
accordance with S6.2, both before and after the 
warning device has been conditioned in accord- 
ance with S6.1, its total candlepower per incident 
foot candle shall be not less than the values 
specified in Table I for each of the listed entrance 
angles. 

55.5 Luminance. When the orange fluores- 
cent material on the warning device is tested in 
accordance with S6.3, both before and after the 
warning device has been conditioned in accord- 
ance with S6.1, it shall have a minimum relative 
luminance of 25 percent of a flat magnesium 
oxide surface and a minimum product of that 
relative luminance and width in inches of 44. 

55.6 Stability. When the warning device is 
erected on a horizontal brushed concrete surface 
both with and against the brush marks and sub- 
jected to a horizontal wind of 40 miles per hour 
in any direction for 3 minutes— 

(a) No part of it shall slide more than 3 inches 
from its initial position; 

(b) Its triangular potion shall not tilt to a 
position that is more than 10° from the vertical; 
and 

(c) Its triangular position shall not turn 
through a horizontal angle of more than 10° in 
either direction from the initial position. 



PART 571; S 125-3 



Table 1. Total Minimum Candlepower Per Incident Foot Candle 

Entrance Angles - Degrees 



Observation 
Angles-Degrees 





10 
up 


10 
down 


20 
left 


20 
right 


30 

left 


30 
right 


0.2 


80 


80 


80 


40 


40 


8.0 


8.0 


1.5 


0.8 


0.8 


0.8 


0.4 


0.4 


0.08 


0.08 



S5.7 Durability. When the warning device is 
conditioned in accordance with S6.1, no part of 
the warning device shall become warped or sepa- 
rated from the rest of the warning device. 

S6. Test Procedures. 

56.1 Conditions. 

S6.1.1 Submit the warning device to the fol- 
lowing conditioning sequence, returning the device 
after each step in the sequence to ambient air at 
68° F. for at least 2 hours. 

(a) Minus 40° F. for 16 hours in a circulating 
air chamber using ambient air which would have 
not less than 30 percent and not more than 70 
percent relative humidity at 70° F.; 

(b) 150° F. for 16 hours in a circulating air 
oven using ambient air which would have not less 
than 30 percent and not more than 70 percent 
relative humidity at 70° F.; 

(c) 100° F. and 90 percent relative humidity 
for 16 hours; 

(d) Salt spray (fog) test in accordance with 
American Society of Testing and Materials 
Standard B-117, Standard Method of Salt Spray 
(fog) testing, August 1964, except that the test 
shall be for 4 hours rather than 40 hours; and 

(e) Immersion for 2 hours in water at a tem- 
perature of 100° F. 

56.2 Reflectivity Test. Test the red reflex 
reflective material as follows: 

(a) Unless dual purpose material is used, pre- 
vent the orange fluorescent material from affect- 
ing the photometric measurement of the reflec- 
tivity of the red reflex reflective material, either 
by separation or masking. 



(b) Use a lamp with a tungsten filament op- 
erating at 2856° Kelvin color temperature as the 
source of illumination. 

(c) Place the source of illumination 100 feet 
from the red reflex reflective material (Figure 2). 

(d) Place the observation point directly above 
the source of illumination (Figure 2). 

(e) Calculate the total candlepower per in- 
cident foot candle of the red reflex reflective 
material at each of the entrance and observation 
angles specified in Table 1. 

S6.3 Luminance Test. Test the orange fluores- 
cent material as follows: 

(a) Unless dual purpose material is used, pre- 
vent the red reflex reflective material from affect- 
ing the photometric measurement of the lumin- 
ance of the orange fluorescent material. 

(b) Using a 150-watt high pressure xenon com- 
pact arc lamp as the light source, illuminate the 
test sample at an angle of incidence of 45° and 
an angle of observation of 90°. If dual purpose 
material is being tested, illuminate the sample 
diffusely through an integrating sphere. 

(c) Measure the luminance of the material at 
a perpendicular viewing angle, with no ray of 
the viewing beam more than 5° from the per- 
pendicular to the specimen. 

(d) Repeat the procedure for a flat magnesium 
oxide surface, and compute the quotient (per- 
centage) of the luminance of the material relative 
to that of the magnesium oxide surface. 

37 F.R. 5038 
March 9, 1972 



PART 571; S 125-4 



Elhctlvc January 1, 1973 
(Except a% Noted In Rulal 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 126 

Truck-Camper Loading 
(Docket No. 71-7; Notice 2) 



This notice amends Part 571 of Title 49, Code 
of Federal Eegulations, to add a new Motor 
Vehicle Safety Standard No. 126 (49 CFR 
571.126) that requires manufacturers of slide-in 
campers and of trucks that would accommodate 
them to provide information concerning proper 
loading and load distribution. A notice of pro- 
posed rulemaking on this subject was published 
on April 9, 1971 (36 F.R. 6837). 

The purpose of the new standard is to provide 
information that can be used to reduce overload- 
ing and improper load distribution in truck- 
camper combinations, and to prevent accidents 
re?ulting from the adverse effects of these con- 
ditions on vehicle handling and braking. Stand- 
ard No. 126 requires manufacturers of slide-in 
campers to permanently affix a label to a rear 
surface of each camper that includes the weight 
of the camper when it contains standard equip- 
ment, and water, bottled gas, and ice box with 
ice or refrigerator. The camper manufacturer 
is also required to provide, in an owner's manual 
or other document delivered with the camper, a 
picture showing the location of the longitudinal 
center of gravity of the camper when loaded and 
a picture showing a proper match of the slide-in 
camper on a typical truck. Standard No. 126 
also requires manufacturers of trucks to which a 
camper could be attached to provide, in an oper- 
ator's manual or other document delivered with 
the truck, a picture showing the manufacturer's 
recommended longitudinal center of gravity zone 
for the cargo weight rating, and one depicting 
the proper match of a truck and slide-in camper. 

Standard No. 126 differs from the proposal m 
several aspects. The standard as proposed would 
have applied to incomplete vehicles intended for 
completion as trucks, and to multipurpose pas- 
senger vehicles with a GVWR of 10,000 pounds 



or less. These categories have been excluded 
from the final rule, which applies to trucks that. 
would accommodate slide-in campers. These 
generally are pick-up trucks. In excluding other 
proposed categories the NHTSA considers that 
the information the manufacturer of an incom- 
plete vehicle must furnish pursuant to 49 CFR 
Part 568, Vehicles Manufactured in Two or More 
Stages, should be sufficient to assist a final as- 
sembler in permanently installing a chassis- 
mount camper on a truck chassis, or in assembling 
a vehicle such as a motor home. 

The proposal would also have required that a 
label be permanently affixed to each cargo com- 
partment that would specify the maximum rec- 
ommended weight for a load placed in the 
compartment. Commenters argued persuasively 
that camper owners would disregard a series of 
weight capacity labels on all storage comparts 
ments, and the proposal was not adopted. The 
final rule requires the certification label and the 
owner's manual to provide a figure denoting 
camper weight, which as noted previously in- 
cludes the weight of standard equipment, a re- 
frigerator, or ice box with ice, and maximum 
capacity of water and bottled gas. The cubic 
capacity of the refrigerator or weight of ice, the 
weight of bottled gas, and the gallons of water 
encompassed in the maximum weight figure will 
also be listed on the permanent label and in the 
owner's manual. The camper manufacturer may 
exclude any of these items from the label if the 
camper is not designed to accommodate them, 
provided that a notation to that effect appears in 
the owner's manual. The standard also requires 
a manufacturer to provide a listing of optional 
or additional equipment that the camper is de- 
signed to carry, and the respective weight of 
each if the unit weight exceeds 20 pounds. 



PART 571; S 126— PRE 1 



EffacHve: January 1, 1973 
(Except at Noted in Rule) 

The label will also state the month and year of 
manufacture, and a recommendation that the user 
consult the owner's manual or data sheet for the 
weight of optional and additional equipment. 
The label is to be mounted in a plainly visible 
location on a surface at the rear of the camper 
other than the roof, steps or bumper extension. 

The proposed reference point, or the distances 
of the camper center of gravity from the refer- 
ence point, have not been adopted for use on the 
exterior label. Manufacturers of campers gen- 
erally have had no experience with the relatively 
complex vertical center of gravity measurement 
techniques. Truck manufacturers pointed out a 
nimiber of variables that would have to be con- 
sidered, and stated that the limiting envelope 
would not be rectangular as implied by the pro- 
posal. Other comments objected to the end of 
the truck's axle shaft as a reference point for 
specifying a recommended cargo center of grav- 
ity zone. Variations in the longitudinal center 
of gravity of the load are, however, known to 
have a direct relationship to a truck's gross axle 
loading, and can adversely affect the steering and 
stopping ability of the vehicle. The camper 
manufacturer will therefore be required to pro- 
vide in the owner's manual a picture showing the 
location of the camper's longitudinal center of 
gravity within 2 inches, under specified load con- 
ditions. A manufacturer can easily measure the 
longitudinal center of gravity of a slide-in 
camper by balancing it on a transverse horizontal 
rod. The camper owner's manual must also con- 
tain specific advice on proper choice of truck to 
which a camper may be mounted, and proper 
loading of the camper once it is attached. Truck 



manufacturers in turn are required to include in 
the operator's manual a picture showing the rec- 
ommended longitudinal center of gravity zone 
for the cargo weight rating and loading recom- 
mendations. 

In order to allow the relatively small camper 
manufacturers time to consider the recommenda- 
tions of truck manufacturers, and to modify 
camper designs if needed, a camper manufacturer 
need not provide center of gravity location in- 
formation until July 1, 1973. 

Effective date: January 1, 1973, with addi- 
tional requirements effective July 1, 1973. Be- 
cause compliance with the rule does not involve 
extensive leadtime, the Administrator finds for 
good cause shown that an effective date earlier 
than one hundred eighty days after issuance is 
in the public interest. 

In consideration of the foregoing, 49 CFR 
Part 571 is amended by adding § 571.126, Stand- 
ard No. 126, Truck-Camper Loading. . . . 

This notice is issued xmder the authority of 
Sections 103, 112, 114, and 119 of the National 
Traffic and Motor Vehicle Safety Act of 1966 
(15 U.S.C. 1392, 1401, 1403, and 1407) and the 
delegation of authority from the Secretary of 
Transportation to the National Highway Traffic 
Safety Administrator, 49 CFR 1.51. 

Issued on August 3, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 16497 
August 15, 1972 



PART 571; S 126— PRE 2 



Effective: January 1, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 126 

Truck-Camper Loading 
(Docket No. 71-7; Notice 4) 



This notice responds to petitions for reconsid- 
eration of 49 CFR § 571.126, Motor Vehicle 
Safety Standard No. 126, Trv/)k-Cainper Load- 
ing. The portion of the regulation requiring 
information to be provided by camper manu- 
facturers is retained as a Federal motor vehicle 
safety standard, and a vehicle information num- 
ber is added to the list of information to be pro- 
vided. The portion of the rule applicable to 
truck manufacturers is reissued as a consumer 
information regulation by a separate notice (37 
F.R. 26607). 

Standard No. 126, establishing requirements 
for slide- in campers and trucks that would ac- 
commodate them, was published on August 15, 
1972 (37 F.R. 16497). Thereafter, pursuant to 
49 CFR § 553.35, petitions for reconsideration of 
the standard were filed by Chrysler Corporation 
(Chrysler), Ford Motor Company (Ford), 
General Motors Corporation (GM), Jeep Cor- 
poration (Jeep), Motor Vehicle Manufacturers 
Association of the United States, Inc. (MVMA), 
Recreational Vehicle Institute, Inc. (RVI), and 
Toyota Motor Sales, U.S.A., Inc. (Toyota). 

In response to information contained in several 
of these petitions the standard is being amended 
in certain respects. The Administrator has de- 
clined to grant requested relief from other re- 
quirements of the standard. 

1. Statutory Aiithority. Standard No. 126 as 
issued applied to slide-in campers and to trucks 
that would accommodate them. It required man- 
ufacturers of slide-in campers to attach to their 
products a label containing the name of the man- 
ufacturer, the month and year of manufacture, 
a certification of conformity, and information 
concerning the camper's maximum weight. The 
standard also required camper manufacturers to 



provide the same information and certain addi- 
tional items in a manual or other document to 
accompany each camper. A parallel requirement 
was adopted applicable to truck manufacturers; 
they were required to provide information in a 
manual or other document supplied with their 
products that would assist truck owners in choos- 
ing a properly matched camper. 

Chrysler, Ford, GM, Jeep, and MVMA ques- 
tioned the authority to issue the requirements of 
49 CFR §571.126 as a Federal motor vehicle 
safety standard rather than in the form of a 
Consumer Information Regulation (49 CFR 
Part 575), alleging that Standard No. 126 is 
"neither a performance standard nor does it pro- 
vide any objective criteria for determining com- 
pliance." 

The NHTSA does not agree that it lacks au- 
thority to issue Standard No. 126 in the form 
in which it appeared. Actually, the regulation 
was issued under the combined authority of four 
sections of the Act: section 103 (the authority 
for the Federal motor vehicle safety standards), 
section 112 (the primary authority for technical 
information and data to be provided by a manu- 
facturer to NHTSA and the consumer), section 
114 (the authority for vehicle and equipment 
certification) and section 119 (the general rule- 
making authority). Many of the existing stand- 
ards contain information requirements, and it is 
the position of this agency that such provisions 
fully satisfy the statutory criteria as objective 
performance requirements. The question there- 
fore is in most respects the merely formal one of 
whether the rule is called a "safety standard" 
or a "consumer information regulation," and 
codified accordingly. 



PART 571; S 126— PRE 3 



Effective: January 1, 1973 



On reconsideration of all aspects of the stand- 
ard, however, this agency has determined that 
there is an advantage to issuing the requirements 
for trucks in the form of a consumer informa- 
tion regulation. 49 CFR § 575.6(b) requires all 
Part 575 consumer information to be made avail- 
able to prospective purchasers in dealer sliow- 
rooms, and paragraph (c) of that section re- 
quires such information to be furnished directly 
to the NHTSA. Neither of these requirements 
applies to information furnished pursuant to 
Part 571 safety standards. Part 575 consumer 
information regulations are enforceable in sub- 
stantially the same manner and with the same 
sanctions as safety standards. The requirements 
for trucks in 49 CFR §571.126 are therefore 
reissued as a new consumer information regula- 
tion, 49 CFR § 575.103, by an action published 
in this issue, 37 F.R. 26607. 

2. Effective date. The requirement for pic- 
tures showing camper center of gravity and 
proper truck-camper match that camper manu- 
facturers were to provide as of July 1, 1973, is 
being deferred 2 months, and will not be required 
until September 1, 1973. RVI has petitioned for 
an extension of the effective date of these require- 
ments to January 1, 1974, on the basis that the 
extension "would give the relatively small 
camper manufacturers additional time to con- 
form camper design to the center of gravity 
envelopes developed by the truck manufacturers." 
The regulation, however, only requires manufac- 
turers to provide information, not to redesign 
their products. The NHTSA finds that RVI 
has shown insufficient justification to support its 
request, and the petition is denied. 

3. Definitions. RVI petitioned that its defini- 
tion of "camper" be adopted so that there would 
be no confusion within the recreational vehicle 
industry as to whether the standard applied to 
motor homes and pickup covers. RVI's petition 
was similar to the one it submitted for recon- 
sideration of Standard No. 205, Glazing Ma- 
terials. The NHTSA has not adopted the RVI 
definition, but it has defined the terms "camper" 
and "slide-in camper" so as to clarify these terms 
and differentiate them from "motor home" and 
"pickup cover," also defined in Standard No. 205. 
"Cargo weight rating" was defined as "the maxi- 
mum weight of cargo . . . that can safely be 



carried by a vehicle under normal operating 
conditions. . . ." Ford objects that the definition 
is subjective and urges that the term be redefined 
as "the maximum weight of cargo . . . that the 
truck manufacturer specifies may be carried on 
the vehicle." The NHTSA concurs generally 
with Ford's views. The definition has been re- 
written to make clear that the rating, like GVWR 
and GAWR, is to be assigned at the discretion 
of the manufacturer. 

4. Informatio7i. Ford believes the reference 
to "total load" in paragraph S5. 1.2(c) is mis- 
leading "in that users may easily understand this 
to be the total load on the truck." It suggests 
substitution of the term "cargo load." Ford's 
point is well made, and the term is redesignated 
"total cargo load" as a clarification. 

Toyota has asked that paragraph S5. 1.2(e) 
be amended to substitute four inches for the re- 
quirement that camper manufacturers provide 
a picture showing the location of the center of 
gravity of the camper within an accuracy of two 
inches under the loaded condition. The petition 
is denied. The intent of the specification is to 
insure an accuracy within two inches, in either 
direction, in effect, a range of four inches. The 
NHTSA does not consider this tolerance to be 
overly demanding. 

Finally, RVI states that its members have had 
difficulty in interpreting Figure 2 and requests 
the NHTSA to more clearly indicate "that the 
terminology 'Mount at Aft End of Truck Cargo 
Area' means that the designated point in the 
figure signifies the point where the identified 
surface of the camper abuts the rearmost edge 
or surface of the cargo area of the truck, pre- 
sumably the tailgate in most configurations." To 
clarify its intent the NHTSA is changing the 
language in question to "point that contacts rear 
end of truck bed." 

5. Vehicle Identification Number (VIN.) The 
NHTSA proposed on August 15, 1972 (Docket 
No. 71-7; Notice 3, F.R. 16505) that slide-in 
campers be identified by a VIN, consisting of 
arable numerals, roman letters, or both. The 
notice also proposed to require that the VIN of 
two campers manufactured by a manufacturer 
within a ten year period shall not be identical. 
No objections were raised to the proposal, and 
Standard No. 126 is amended to adopt the pro- 



PART 571; S 126— PRE 4 



Eff»cMv«: January 1, 1973 



posed requirements, reworded slightly effective 
January 1, 1973. 

In consideration of the foregoing, 49 CFR 
§ 571.126, Motor Vehicle Safety Standard No. 
126, is amended. . . . 

Effective date: January 1, 1973, with addi- 
tional requirements effective September 1, 1973. 
Because the amendment consists principally of 
the reissue of existing requirements, and com- 
pliance with the amendment requiring a VIN 
does not involve extensive leadtime, the Admin- 
istrator finds for good cause shown that an effec- 
tive date eariler than 180 days after issuance is 
in the public interest. 



This notice is issued under the authority of 
sections 103, 112, 114, and 119 of the National 
Traffic and Motor Vehicle Safety Act of 1966 
(15 U.S.C. 1392, 1401, 1403, and 1407) and the 
delegation of authority from the Secretary of 
Transportation to the National Highway Traffic 
Safety Administrator, 49 CFR 1.51. 

Issued on: December 6, 1972. 

Douglas W. Toms 
Administrator 

37 F.R. 26605 
December 14, 1972 



PART 571; S 126— PRE 5-6 



Efftctlvs: February 14, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 126 

Truck-Camper Loading 
(Docket No. 71-7; Notice 7) 



This notice responds to a petition for reconsid- 
eration of 49 CFR § 571.126, Motor Vehicle Safety 
Standard No. 126, Truck-camper loading, with an 
amendment allowing optional wording of a por- 
tion of the placard to be affixed to campers, and 
of other required information. The amendments 
are effective upon publication in the Federal Reg- 
ister. 

On August 15, 1972 Motor Vehicle Safety 
Standard No. 126 was originally published (37 
F.R. 16497). In response to petitions for recon- 
sideration the standard was republished on De- 
cember 14, 1972 (37 F.R. 26605) with amendments 
that included minor changes in the text of infor- 
mation required to be furnished to purchasers of 
slide-in campers. 

Paragraph S5.1.2(a) of Standard No. 126 re- 
quires each manufacturer of a slide-in camper 
to provide in a manual or other document deliv- 
ered with each camper "the statement and infor- 
mation provided on the certification label as 
specified in paragraph S5.1.1". Among this in- 
formation is the month and year that the camper 
was manufactured. The Trailer Coach Associa- 
tion has asked in a letter dated December 29, 
1972 that wording such as "see certification label 
for date of manufacture" be substituted for the 
month and year of manufacture, contending that 
"to require manufacturers to list the month and 
year of manufacture in each vehicle owner's 
manual would be an unnecessary hardship in 
view of the production and shipping schedule 
which varies greatly from time to time during 
the year." 

The NHTSA believes that the request of TCA 
is reasonable, and is treating TCA's letter as a 
petition for reconsideration filed pursuant to 49 
CFR 553.35. However, since the information 



requirement became effective January 1, 1973, 
and because of the possibility that manufacturers 
now providing this data may wish to continue to 
do so, the manufacturer should have the option 
of including either the month and year of manu- 
facture or a reference to the certification label. 
The standard is being amended to provide this 
option. 

In the amendments published on December 14, 
1972 two minor changes were made in terminol- 
ogy. In Paragraph S5.1.2(c) the phrase "total 
load", which appears twice, was changed to "total 
cargo load" as a clarification. Further clarifica- 
tion was provided in an amendment to Figure 2, 
Camper Center of Gravity Information where the 
legend "Mount at Aft End of Truck Cargo Area" 
was changed to "Point That Contacts Rear End 
of Truck Bed". In view of the amendments to 
§ 575.103 delaying the effective date 30 days until 
April 1, 1973, and permitting use of the earlier 
form until October 1, 1973 (Docket No. 71-7; 
Notice 6 (38 F.R. 4400)), camper manufactur- 
ers who have printed manuals with the old 
terminology should be afforded the same oppor- 
tunity as truck manufacturers to exhaust obsolete 
stocks of materials. Appropriate amendments are 
therefore made to Standard No. 126, including a 
30 day delay in the pictorial information that 
was to have been provided as of September 1, 
1973. 

In consideration of the foregoing 49 CFR 
§ 571.126 Motor Vehicle Safety Standard No. 126 
is amended .... 

E-ffective date : February 14, 1973. Because the 
amendments create no additional burden it is 
found for good cause that an effective date earlier 
than one hundred eighty days after issuance is 
in the public interest. 



PART 571; S 126— PRE 7 



Effective: February 14, 1973 

(Sec. 103, 112, 114, and 119, Pub. L. 89-563, 
80 Stat. 718, 15 U.S.C. 1392, 1401, 1403 and 1407; 
delegation of authority at 49 CFR 1.51.) 

Issued on February 12, 1973. 

Douglas W. Toms 
Administrator 

38 F.R. 4399 
February 14, 1973 



PART 571; S 126— PRE 8 



Effective: March 9, 1973 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 126 

Truck-Camper Loading 
(Docket No. 71-7; Notice 8) 



This notice corrects the amendment to 49 CFR 
§571.126, Standard No. 126, Truck-camfer 
loading, published on February 14, 1973 (38 
F.R. 4399). The amendment to paragraph 
S5.1.2(a) erroneously referred to "the informa- 
tion required by subparagraphs (c) and (d) of 
paragraph S5.1.1". The reference should have 
been to "subparagraphs (b) and (c)". 

Additionally, the opening statement of the 
preamble erroneously stated that the amendment 
allowed "optional wording of a portion of the 
"'icard to be affixed to campers, and of other 
required information". The amendment itself 
correctly allowed optional wording of informa- 



tion provided in the manual or other document 
delivered with the camper, not on the placard. 

Effective date: March 9, 1973. Because the 
amendment corrects an error, it is found for 
good cause shown that an immediate eflfective 
date is in the public interest. 

(Sec. 103, 112, 114 and 119, Pub. L. 89-563, 
80 Stat. 718, 15 U.S.C. 1392, 1401, 1403, and 
1407; delegation of authority at 49 CFR 1.51.) 

Issued on March 5, 1973. 

Douglas W. Toms 
Administrator 

38 F.R. 6392 
March 9, 1973 



PART 571; S 126— PRE 9-10 



Effective: April 27, 1978 



PREAMBLE TO MOTOR VEHICLE SAFETY STANDARD NO. 126 

Truck-Camper Loading 
(Docket No. 71-7; Notice 10) 



This notice amends Standard No. 126, Truck- 
Camper Loading, by removing the requirement 
that a camper's vehicle identification number 
(VIN) be printed in its owner's manual. Such 
a modification will reduce the cost of compliance 
with the standard, without adversely affecting 
the level of safety prescribed. 
Effective Date: April 27, 1978. 
For Further Information Contact: 
Kevin Cavey, Crash Avoidance Division, 
Office of Vehicle Safety Standards, National 
Highway Traffic Safety Administration, 400 
Seventh Street, S.W., Washington, D.C. 
20590 (202-426-2716). 

Supplementary Information : On November 29, 
1973, the NHTSA issued a notice proposing to 
amend Standard No. 126, Truck-Camper Load- 
ing, to remove the requirement that the vehicle 
identification number (VIN) of each camper be 
printed in its owner's manual (38 FR 32945). 
The amendment, requested by the Recreation 
Vehicle Industry Association, was proposed to 
reduce the burdens and costs associated with com- 
pliance with the requirement. 

Comments were received from Ford, the 
Recreation Vehicle Industry Association, and the 
Recreational Vehicle Division of the Trailer 
Coach Association. The Vehicle Equipment 
Safety Commission did not submit comments. 

The three comments received supported the 
suggested modification. Some commenters as- 
serted that the requirement added little to vehicle 
safety while resulting in increased costs and the 



increased possibility of errors associated with 
inserting the incorrect VIN in an owner's manual. 
The NHTSA concurs with the commenters and 
concludes that the intent of the requirement can 
be achieved by permitting a manufacturer to 
state in the owner's manual that the VIN can 
be found by referring to the camper's certifica- 
tion label. Accordingly, Standard No. 126 is 
amended to make optional the provision of the 
VIN in a camper's owner's manual. If the VIN 
is not placed in the owner's manual, a reference 
must be made in the manual to the location of 
the VIN on the certification label. 

In consideration of the foregoing, the second 
sentence of paragraph S5.1.2 of Standard No. 
126, 49 CFR Part 571.126 is amended. . . . 

Since this amendment relieves a restriction and 
imposes additional burden on any person, it is 
found for good cause shown that an immediate 
effective dat« is in the public interest. 

The principal authors of this notice are Kevin 
Cavey of the Office of Vehicle Safety Standards 
and Roger Tilton of the Office of Chief Counsel. 

(Sees. 103, 119, Pub. L. 89-563, 80 Stat. 718 
(15 U.S.C. 1392, 1407) ; delegation of authority 
at 49 CFR 1.50.) 

Issued on April 21, 1978. 

Joan Claybrook 
Administrator 

43 F.R. 17946 
April 27, 1978 



PART 571; S 126— PRE 11-12 



e 



MOTOR VEHICLE SAFETY STANDARD NO. 126 



Truck-Camper Loading 

(Docket No. 71-7; Notice 2) 



51. Scope. This standard requires manufac- 
turers of slide-in campers to affix a label to each 
camper that contains information relating to 
certification, identification, and proper loading, 
and to provide more detailed loading informa- 
tion in the owner's manual. 

52. Purpose. The purpose of this standard 
is to provide information that can be used to 
reduce overloading and improper load placement 
in truck-camper combinations, and unsafe truck- 
camper matching, in order to prevent accidents 
resulting from the adverse effects of these condi- 
tions on vehicle steering and braking. 

53. Application. This standard applies to 
slide-in campers. 

54. Definitions. 

"Camper" means a structure designed to be 
mounted in the cargo area of a truck, or attached 
to an incomplete vehicle with motive power, for 
the purpose of providing shelter for persons. 

"Cargo weight rating" means the value spec- 
ified by the manufacturer as the cargo-carrying 
capacity, in pounds, of a vehicle, exclusive of the 
weight of occupants in designated seating posi- 
tions. 

"Slide-in camper" means a camper having a 
roof, floor and sides, designed to be mounted on 
and removable from the cargo area of a truck 
by the user. 

55. Requirements. 

S5.1 Slide-in camper. 

S5.1.1 Labels. Each slide-in camper shall have 
permanently affixed to it, in a manner that it 



cannot be removed without defacing or destroy- 
ing it, in a plainly visible location on an exterior 
rear surface other than the roof, steps, or bumper 
extension, a label containing the following infor- 
mation in the English language lettered in block 
capitals and numerals not less than %2-inch high, 
of a color contrasting with the background, in 
the order shown below and in the form illustrated 
in Figure 1. 



MFG. BY: (CAMPER MANUFACTURER'S NAME) 

(MONTH AND YEAR OF MANUFACTURE) 

THIS CAMPER CONFORMS TO ALL APPLICABLE FEDERAL 

MOTOR VEHICLE SAFETY STANDARDS IN EFFECT ON THE 

DATE OF MANUFACTURE SHOWN ABOVE. 

CAMPER WEIGHT IS LBS. MAXIMUM 

WHEN IT CONTAINS STANDARD EQUIPMENT, 

GAL. OF WATER, LBS. OF BOTTLED GAS, 

AND CUBIC FT. REFRIGERATOR (or ICE 



BOX WITH 



LBS. OF ICE, as applicable). 



CONSULT OWNER'S MANUAL (or DATA SHEET as applicable) 
FOR WEIGHTS OF ADDITIONAL OR OPTIONAL EQUIPMENT. 

(VEHICLE IDENTIFICATION NUMBER) 



Figure 1. Label for Campers 

(a) Name of camper manufacturer. The full 
corporate or individual name of the actual as- 
sembler of the camper shall be spelled out, except 
that such abbreviations as "Co.," or "Inc.," and 
their foreign equivalents, and the first and mid- 
dle initials of individuals may be used. The 
name of the manufacturer shall be preceded by 
the words "Manufactured By" or "Mfd. By". 

(b) Month and year of manufacture. It may 
be spelled out (e.g., "June 1973"), or expressed 
in numerals (e.g., "6/73). 

(c) The statement: "This camper conforms to 
all applicable Federal Motor Vehicle Safety 



PART 571; S 126-1 



Standards in effect on the date of manufacture 
shown above." The expression "U.S." or 
"U.S.A." may be inserted before the word 
"Federal." 

(d) The following statement completed as ap- 
propriate: "CAMPER WEIGHT IS 

LBS. MAXIMUM WHEN IT CONTAINS 

STANDARD EQUIPMENT, GAL. 

OF WATER, _____ LBS. OF BOTTLED 
GAS, AND CUBIC FT. REFRIG- 



ERATOR (or ICE BOX WITH 



LBS. 



OF ICE, as apphcable). CONSULT OWN- 
ER'S MANUAL (or DATA SHEET as ap- 
plicable) FOR WEIGHTS OF ADDITIONAL 
OR OPTIONAL EQUIPMENT." 

"Gal. of water" refers to the volume of water 
necessary to fill the camper's fresh water tanks to 
capacity. "Lbs. of bottled gas" refers to the 
weight of gas necessary to fill the camper's 
bottled gas tanks to capacity. The statement 
regarding a "Refrigerator" or "Icebox" refers to 
the capacity of the refrigerator with which the 
vehicle is equipped or the weight of the ice with 
which the icebox may be filled. Any of these 
items may be omitted from the statement, if the 
corresponding accessories are not included with 
the camper, provided that the omission is noted 
in the camper owner's manual as required in 
paragraph S5. 1.2(a). 

(e) Vehicle Identification Number. Each 
slide-in camper shall have a number assigned by 
its manufacturer for identification purposes con- 
sisting of arable numerals, roman letters, or both. 
No two slide-in campers manufactured by the 
same manufacturer within any 10-year period 
shall have the same Vehicle Identification Num- 
ber. 

S5.1.2 Owner's manual. Each slide-in camper 
manufacturer shall provide with each camper a 
manual or other document containing the infor- 
mation specified in S5. 1.2(a) through S5. 1.2(d). 
The information in S5. 1.2(e) and S5. 1.2(f) shall 
also be provided with each camper manufactured 
on or after October 1, 1973. 



(a) The statement and information provided 
on the certification label as specified in paragraph 
S5.1.1. Instead of the information required by 
subparagraphs (b), (c), and (e) of paragraph 
S5.1.1, a manufacturer may use the statements, 
"See camper certification label (located on 
camper's rear exterior surface) for month and 
year of manufacture and for the Vehicle Iden- 
tification Number" and "This camper conforms 
to all applicable Federal Motor Vehicle Safety 
Standards in effect on the date of manufacture." 

(b) A list of other additional or optional 
equipment that the camper is designed to carry, 
and the maximum weight of each if its weight 
is more than 20 lbs. when installed. 

(c) The statement: "To estimate the total 
cargo load that will be placed on a truck, add the 
weight of all passengers in the camper, the weight 
of supplies, tools, and all other cargo, the weight 
of installed additional or optional camper equip- 
ment, and the manufacturer's camper weight 
figure. Select a truck that has a cargo weight 
rating that is equal to or greater than the total 
cargo load of the camper, and whose manufacturer 
recommends a cargo center of gravity zone that 
will contain the camper's center of gravity when 
it is installed." Until October 1, 1973, the phrase 
"total load" may be used instead of "total cargo 
load." 

(d) The statements: "When loading this 
camper store heavy gear first, keeping it on or 
close to the camper floor. Place heavy things far 
enough forward to keep the loaded camper's 
center of gravity within the zone recommended 
by the truck manufacturer. Store only light ob- 
jects on high shelves. Distribute weight to ob- 
tain even side-to-side balance of the loaded 
vehicle. Secure loose items to prevent weight 
shifts that could affect the balance of your ve- 
hicle. When the truck-camper is loaded, drive 
to a scale and weigh on the front and on the rear 
wheels separately to determine axle loads. The 
load on an axle should not exceed its gross axle 
weight rating (GAWR). The total of the axle 
loads should not exceed the gross vehicle weight 
rating (GVWR). These weight ratings are 
given on the vehicle certification label that is 
located on the left side of the vehicle, normally 
the dash panel, hinge pillar, door latch post, or 
door edge next to the driver on trucks manu- 



PART 571; S 126-2 



factured on or after January 1, 1972. If weight 
ratings are exceeded, move or remove items to 
bring all weights below the ratings." 

(e) A picture showing the location of the 
longitudinal center of gravity of the camper 
within an accuracy of 2 inches under the loaded 
condition specified in paragraph S5. 1.1(d), in the 
manner illustrated in Figure 2. Until October 1, 
1973 the phrase "Mount at Aft End of Truck 
Cargo Area" may be used in Figure 2 instead of 
"Point That Contacts Rear End of Truck Bed". 



(f) A picture showing the proper match of a 
truck and slide-in camper in the form illustrated 
in Figure 3. 



CAMPER MANUFACTURER'S NAME 




□ □ 



m 



FIGURE 3 EXAMPLE OF PROPER TRUCK ANO CAMPER MATCH 



CENTER OF GRAVITY LOCATION 
UNDER SPECIFIED LOADING 
CONDITION 



1- POINT THAT 

CONTACTS REAR 
END OF TRUCK 
BED 



FIGURE 2 CAMPER CENTER OF GRAVITY INFORMATION 



37 F.R. 16497 
August 15, 1972 



PART 571; S 126-3 



I 



I 



< 



Effactiv*: January 1, 196S 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO.201 

Occupant Protection In Interior Impact — Passenger Cars 

(Docket No. 19) 



Motor Vehicle Safety Standard No. 201, issued 
January 31, 1967, and published in the Federal 
Register, February 3, 1967 (32 F.R. 2413), speci- 
fies requirements for instrument panels, seat 
backs, protrusions, sun visors, and armrests to 
afford impact protection for occupants of passen- 
ger cars manufactured after January 1, 1968. 

Parties adversely affected by the Standard 
were permitted to petition for reconsideration 
on or before March 6, 1967, pursuant to 23 CFR 
215.17. By order dated March 29, 1967, the 
Acting Under Secretary of Commerce for Trans- 
portation consolidated the 27 petitions related 
to Standard No. 201 and ordered that a hearing 
on reconsiderations be held. 

On April 21, 1967, the Federal Highway Ad- 
ministration issued an order directing that a 
rule-making hearing be held pursuant to 5 U.S.C. 
553 (formerly sec. 4 of the Administrative Pro- 
cedure Act (60 Stat. 238, 5 U.S.C. 1003). The 
hearing was held May 22 and 23, 1967, at Detroit, 
Mich., and May 24 and 25, 1967, at Washington, 
D.C. On June 22, 1967, the presiding officer 
submitted his Report of Recommended Findings 
to the Federal Highway Administration. 

On June 8 and 9, 1967, and July 6 and 7, 1967, 
meetings were held by the National Highway 
Safety Bureau with domestic and foreign auto 
industry engineers in which detailed engineering 
discussions of all problems of compliance with 
the Standard were held. 

After review of the evidence presented at the 
hearings ordered by the Federal Highway Ad- 
ministration, the report of the presiding officer. 



and the Bureau's analysis of the engineering 
meetings with the industry, I have determined 
that Standard 201 issued January 31, 1967, should 
be superseded by a new Standard that specifies 
initial requirements to afford impact protection 
for occupants, and that certain related definitions 
should be amended accordingly. 

Good cause is shown that an effective date 
earlier than 180 days after issuance is in the 
public interest and notice and public procedure 
hereon are unnecessary since these amendments 
relieve restrictions and impose no additional 
burden on any person. 

In consideration of the foregoing. Part 371, 
Initial Federal Motor Vehicle Safety Standards, 
is amended by superseding § 371.21, Motor Ve- 
hicle Safety Standard No. 201 (32 F.R. 2413), 
with a new Motor Vehicle Safety Standard No. 
201 .. . and by amending § 371.3(b). . . . 

These amendments are made under the author- 
ity of sections 103 and 119 of the National Traffic 
and Motor Vehicle Safety Act of 1966 (15 U.S.C. 
1392, 1407) and the delegation of authority of 
March 31, 1967 (32 F.R. 5606), as amended 
April 6, 1967 (32 F.R. 6495), and becomes effec- 
tive January 1, 1968. 

Issued in Washington, D.C, on August 11, 
1967. 

Lowell K. Bridwell, 

Federal Highway Administrator 

32 F.R. 11776 
August 16, 1967 



PART 571; S 201— PRE 1-2 



i 



PREAMBLE TO AMENDMENTS TO MOTOR VEHICLE SAFETY STANDARDS 

NO. 201 

Occupant Protection in Interior Impact 
(Docket No. 78-116; Notice 2) 



ACTION: Final rule. 

SUMMARY: This notice amends Federal Motor 
Vehicle Safety Standards Nos. 201, 203 and 204 to 
extend their applicability to light trucks, buses and 
multipurpose passenger vehicles (MPV's). The 
notice is issued in response to the rising death and 
injury toll involving these vehicles and to petitions 
by the Center for Auto Safety and the Insurance 
Institute for Highway Safety requesting that these 
standards be extended to those vehicles. Applying 
these standards to light trucks, buses and MPV's 
will reduce occupant deaths and injuries in those 
vehicles by requiring the use of energy absorbing 
material on such interior components as the instru- 
ment panel and seat backs (Standard No. 201), by 
limiting the amount of force that can be exerted on 
the driver's chest by the steering wheel in frontal 
crashes (Standard No. 203), and by limiting the 
rearward movement of the steering assembly in 
frontal crashes (Standard No. 204). 

EFFECTIVE DATE: The effective date for the 
extension of applicability of Standards Nos. 201, 
203 and 204 is September 1, 1981. 

ADDRESS: Petitions for reconsideration should 
refer to the docket number and be submitted to: 
Docket Section, Room 5108, National Highway 
Traffic Safety Administration, 400 Seventh Street, 
S.W., Washington, D.C. 20590. 

FOR FURTHER INFORMATION CONTACT: 

Mr. William Smith, Office of Vehicle Safety 
Standards, National Highway Traffic Safety 
Administration, 400 Seventh Street, S.W., 
Washington, D.C. 20590 (202-426-2242) 



SUPPLEMENTARY INFORMATION: This notice 
amends Standard No. 201, Occupant Protection in 
Interior Impact, and Standard No. 203, Impact 
Protection for the Driver From the Steering 
Control System, to extend the applicability of those 
standards to trucks, buses and multipurpose 
passenger vehicles (MPV's) with a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less. 
This notice also amends Standard No. 204, 
Steering Control Rearward Displacement, to 
extend its applicability to trucks, buses and MPV's 
with an unloaded vehicle weight of 4,000 pounds or 
less, instead of all trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less, as originally 
proposed in the agency's November 9, 1978, notice 
of proposed rulemaking (43 FR 52264). As explained 
below, the agency is initially limiting the extended 
applicability of Standard No. 204 while it studies 
methods for dealing with final-stage manufacturer 
certification difficulties. Similar possible problems 
with Standard No. 212-76, Windshield Mounting, 
and Standard No. 219-75, Windshield Zone Intru- 
sion, led the agency to propose changes in the 
testing procedures for those standards (44 FR 
45426). 

For the purposes of Standard No. 204, the agency 
has determined that these problems would not be 
encountered in applying the standard to vehicles 
with an unloaded vehicle weight of 4,000 pounds or 
less and testing them at their unloaded vehicle 
weight. Approximately 75 percent of the current 
sales of light trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less have an unloaded 
vehicle weight of 4,000 pounds or less. 

This final rule was preceded by a notice propos- 
ing the extension of the applicability of Standards 



PART 571; S 201-PRE-3 



Nos. 201, 203 and 204 in November 1978 (43 FR 
52264). Private citizens, safety organizations, 
manufacturers and a manufacturer trade associa- 
tion submitted comments on the proposal. NHTSA 
has considered all of those comments and the most 
significant ones are discussed below. 

Safety Need 

Citing the need to reduce the number of deaths 
and injuries in light trucks, buses and MPV's, the 
American Automobile Association, the Center for 
Auto Safety, the Insurance Institute for Highway 
Safety and State Farm -Insurance Companies 
supported application of the standards to those 
vehicles. 

Although it did not object to extending the 
applicability of Standard Nos. 201, 203 and 204 to 
light trucks, buses and MPV's, General Motors 
argued that manufacturers should be given a 
longer lead time to comply with the standards 
because of the lack of urgent safety need. GM said 
that allowing a longer leadtime was desirable to 
ensure compliance, "without costly accelerated 
[design] programs." Using data from the agency's 
"Explanation of Rulemaking," GM said that light 
trucks, buses and MPV's have a fatality rate of 
22.4 fatalities per billion miles, compared with a 
rate of 25.3 fatalities per billion miles for 
passenger cars. The data GM used covers fatalities 
during 1977 in all model year vehicles. A new 
analysis done by NHTSA of 1977 fatalities, 
reported by the agency's Fatal Accident Reporting 
System, shows that although older model year 
light trucks, buses and MPV's may have had a 
lower fatality rate than passenger cars, beginning 
with the 1973 model year, the combined fatality 
rate for light trucks, buses and MPV's began 
surpassing that of passenger cars. The analysis 
shows that recent model year passenger cars have 
a considerably lower fatality rate than light trucks, 
buses and MPV's. (A copy of that analysis has been 
placed in the docket.) 

In addition to being higher than the combined 
fatality rate for all sizes of passenger cars, the 
combined fatality rate of light trucks, buses and 
MPV's is far higher than the rate for full-size 
passenger cars. Full-size cars are typically the 
safest of cars and many of them are comparable in 
size and weight to light trucks, buses and MPV's. 
In theory, occupants of larger and heavier vehicles, 
such as trucks, buses and MPV's, should experience 



less harmful crash forces, and thus presumably incur 
fewer or less severe injuries, than occupants of 
smaller lighter vehicles. Volkswagen has previously 
objected to a comparison of full-size passenger 
fatality rates with those for vans, arrguing that 
vans are comparable in weight to intermediate, not 
full-size passenger cars. Although the unloaded 
weight of vans and intermediate-size passenger 
cars may be comparable, vans have a higher gross 
vehicle weight rating which means that those 
vehicles can, in actual use, be loaded with substan- 
tially more weight than intermediate and even full- 
size passenger cars. 

Volkswagen also questioned the safety need for 
the proposed reulmaking because of the voluntary 
comphance by VW and some other companies with 
the standards. Although the voluntary effort by 
some companies is commendable, most manufac- 
turers do not comply with all of the standards in all 
of their vehicles. Some of the manufacturers who 
have taken steps to comply with the standard 
presumably were in part motivvated by prior 
NHTSA rulemaking notices proposing to apply 
Standards Nos. 201,203 and 204 to light trucks, 
buses and MPV's (35 FR 14936, 14936 and 16805). 
In the absence of a regulation, there is no 
assurance that non-complying manufacturers will 
produce complying vehicles and that manfacturers 
producing currently complying vehicles will 
continue to comply. Manufacturers who currently 
comply should experience only minor economic 
impacts, such as conducting certification tests as a 
result of compelling other manufacturers to 
comply. 

Effectiveness 

The Motor Vehicle Manufacturers Association 
(MVMA) questioned the potential effectiveness of 
Standards Nos. 201, 203 and 204. MVMA argue 
that a study done bySherman and Huelke of light 
truck and van accidents found that the standards 
would have little effect in those vehicles. However, 
a NHTSA analysis of the crashes reviewed by 
Sherman and Huelke found that a number of the 
crashes clearly edmonstrated the benefits of equip- 
ping light trucks and vans with energy absorbing 
instrument panels and steering columns and devices 
to limit the rearward displacement of the steering 
column. For example, Sherman and Huelke studied 
a 15-20 mph head-on crash of a 1976 Chevrolet 



PART 571; S 201-PRE-4 



pickup truck into a tree. The Chevrolet was equipped 
with a padded instrument panel, and energy- 
absorbing steering column and a device to limit the 
rearward displacement of the steering column. They 
reported, "the results of this case show that both of 
the major energy absorbing components appeared to 
have completely activated, both by the vehicle crash 
and driver impact, providing maximum benefit to the 
driver. Had this vehicle been one of the other vehicle 
cases discussed in this section, we feel that the in- 
juries sustained by the driver would have been much 
more severe." 

NHTSA believes further that the Sherman and 
Huelke study provides information indicating that 
there is a need for even more improvements in 
light trucks and vans, such as providing energy- 
absorbing padding for the lower instrument panel. 
The agency is studying the question of making 
appropriate changes in the performance 
requirements of the standards to require more pro- 
tection. However, NHTSA considers it important 
not to delay extending the current benefits of 
Standards Nos. 201, 203 and 204 while it reviews 
possible changes to the standards. 

MVMA also argued that a comparison of the 
injury experience of passenger car steering 
assemblies with the experience of steering 
assemblies in light trucks and vans shows that 
Standards Nos. 203 and 204 "would provide little 
benefit" in those vehicles. Using data from the 
agency's original analysis of the injury experience 
of passenger cars produced before and after 
Standards Nos. 203 and 204 took effect, MVMA 
said that the primary benefit of the standards is to 
reduce moderate instead of severe-to-fatal injuries. 
It pointed out that 65.6 percent of the steering 
assembly related injuries in pre-standard cars were 
minor, 22.7 percent were moderate and 11.9 per- 
cent were severe-to-fatal. In post-standard, cars 
78.8 percent of the steering assembly related 
injuries were minor, 10.2 percent were moderate 
and 11.0 were severe-to-fatal. Thus, in post- 
standard cars, many previously moderate injuries 
were only minor injuries. Using data from a 
Calspan study of light truck and van injuries, 
MVMA said that 83.5 percent of the steering 
column related injuries in those vehicles are minor, 
4.1 percent are moderate and 12.4 percent are 
severe-to-fatal. MVMA said that the Calspan data 



indicate that there is "little room" for a passenger 
car-type of injury experience change from moderate 
to minor injuries in light trucks and vans. 

However, the Calspan data cited by MVMA are 
not comparable with the NHTSA data and prob- 
ably underestimate the percentage of moderate 
and severe-to-fatal steering assembly related 
injuries in light trucks and vans. The Calspan data 
include injuries from all types of impacts (front, 
rear and side). The NHTSA data, on the other 
hand, cover only frontal crashes, the type of 
crashes which are most likely to cause severe-to- 
fatal steering assembly related injuries. Thus, the 
percentage of moderate and severe-to-fatal 
injuries found in the NHTSA data should be 
greater. In addition, an updated NHTSA analysis 
of passenger car injury experience, discussed 
below, shows that Standards Nos. 203 and 204 are 
effective in reducing both moderate and severe-to- 
fatal injuries. Further, even if the actual light 
truck and van injury distribution were the same as 
found by Calspan, Standards Nos. 203 and 204 
would be effective in reducing the number of 
severe-to-fatal injuries. 

Several manufacturers and the MVMA objected to 
the agency's use of passenger car data to estimate 
the potential effectiveness of the three standards in 
light trucks, buses and MPV's. They argued that the 
agency should instead have conducted a study com- 
paring the accident experience of light trucks, buses 
and MPV's that currently comply with the standards 
with the experience of those that do not comply. As 
explained below, NHTSA concludes that such a study 
is impractical and that the agency's original and 
updated analyses of passenger car effectiveness data 
are valid and support application of the standards to 
light trucks, buses and MPV's. 

The primary difficulty in conducting a study of 
current light trucks, buses and MPV's is that there 
is no conclusive information identifying which 
vehicles are currently in compliance with the 
standard, since no manufacturer is required to 
certify compliance. For example, International 
Harvester (IH) requested NHTSA to conduct a 
study of currently complying light trucks, buses 
and MPV's, saying that its Scout models were 
designed to comply with the performance re- 
quirements of Standards Nos. 201, 203 and 204. 
However, IH said that if the NHTSA applies the 



PART 571; S 201-PRE-5 



requirements of Standards Nos. 201, 203 and 204. 
However. IH said that if the NHTSA applies the 
standards to light trucks, buses and MPV's, it will 
have to retest the Scout, which "could conceivably 
require some additional redesigning for compliance 
assurance." NHTSA belives that the analysis the 
agency conducted of pre- and post- 1968 passenger 
car injurj' experience, where it was known that 
passenger cars manufactured on or after Januarj' 1 , 
1968, had to comply with Standards Nos. 201. 203 
and 204. pro\ides a sound basis for estimating the 
potential effectiveness of the standards in other 
tj-pes of vehicles. 

Using information recently made available from 
the agency's National Crash Severity Study, 
NHTSA has again compared injuries sustained by 
occupants of cars manufactured before Standards 
Nos. 201. 203 and 204 went into effect with injuries 
sustained by occupants of cars manufactured after 
the standards went into effect. As with the 
agency's first analysis, cited in the November 9. 
1978. notice for this rulemaking, the new analysis 
examined injuries caused by components covered 
by Standard No. 201, such as instrument panels, 
seat backs, arm rests and sun \isors. The analysis 
found that Standard No. 201 reduced severe to 
fatal occupant injuries (i.e.. injuries with an 
abbre\iated injury scale ranking of 3 or more) by 
approximately 38 percent. The analysis also found 
that the probability of an occupant injured in a 
crash being injured by a component covered by 
Standard No. 201 was 25.7 percent. Thus, 
multipljing the probability' of injury (i.e.. 25.7 
percent) by the effectiveness of the standard in 
reducing serious and fatal injuries (i.e., 38 percent) 
the analysis estimated that the overall reduction in 
severe to fatal injuries attributable to Standard 
No. 201 is 9.3 percent. 

A similar comparison was made for occupant 
injuries in cars manufactured before and after 
Standards Nos. 203 and 204 went into effect. The 
comparison examined two sets of driver injuries 
that occurred in frontal crashes. One set consisted 
of injuries that could be specifically attributed to 
contact \dth the steering assembly; the other set 
consisted of neck, chest and abdominal injuries sus- 
tained by drivers in frontal crashes, the t^-pes of 
steering assembly-related injuries the standards 
are designed to reduce. The comparison found that 
Standards Nos. 203 and 204 reduced severe to 
fatal injuries by an average of 20.9 percent. The 



probability of an injured driver receiving an injury 
attributable to the steering assembly was an 
average of 19.4 percent. The analysis estimated 
that Standards Nos. 203 and 204 produced an 
overall average reduction of 3.7 percent in severe 
to fatal driver injuries. 

Load ing Requ i rements 

At present, Standard No. 204 does not specify 
the loading requirements for vehicles in the 30 mph 
fixed barrier crash test required by the standard. 
In conducting Standard No. 204 compliance tests 
for passenger cars, the agency has loaded 
passenger cars to their unloaded vehicle weight 
(i.e., the weight of the vehicle with all the fluid, 
such as gas, oil and water, necessarj' for its opera- 
tion but without any occupants or cargo). This is 
the least severe loading condition used in the 
Federal Motor Vehicle Safety Standards that 
involve crash testing. This notice makes a technical 
amendment to Standard No. 204 to incorporate the 
agency long-standing loading practices. Those 
practices were publicly announced in the 
compliance test procedures publicly released by the 
agency when Standard No. 204 first went into 
effect in 1968. Passenger car certification informa- 
tion pro\ided by manufacturers to NHTSA shows 
that they have consistently used unloaded vehicle 
weight as the loading condition in their testing. In 
some instances, manufacturers have voluntarily 
used more severe loading conditions in their 
certification testing. 

Commercial Vehicles 

Several final stage manufacturers and United 
Parcel Ser\ice requested the agency to exempt 
vehicles used in commercial applications from the 
standards. A similar exemption has previously 
been sought by the Truck Body and Equipment 
Association (TBEA) for Standard No. 212-76, 
Windshield Mounting, and Standard 219-75, 
Wiyidshield Zone Ititrusion. As with the TBEA 
request, NHTSA concludes that such an exemption 
should not be adopted since it is not in the interest 
of safety and is based on vehicle use instead of 
vehicle tj-pe. Such an exemption would mean that 
standards would be applied on the basis of the 
commercial or private use of the vehicle and not 
upon the safety needs of a particular vehicle type. 
Since the safety needs of similar vehicles usually 
are similar, it would be inappropriate to treat one 
set of vehicles differently merely because they are 
used commercially. 



PART 571; S 201-PRE-6 



The National Traffic and Motor Vehicle Safety 
Act contemplates the application of the standards 
based on vehicle type instead of vehicle use. Basing 
a standard on vehicle use would present this agency 
with difficult enforcement problems. It would also 
place a manufacturer in the difficult position of 
having to assess in advance the potential future 
use of the vehicle it produces. In addition, basing 
standards application on vehicle use does not 
recognize that a vehicle may have two or more uses 
during its lifetime. 

For all these reasons, the agency concludes that 
applying standards based on vehicle use would not 
be appropriate. 

Walk-In Vans 

GM, MVMA and several final-stage manufac- 
turers requested the agency to exempt walk-in 
vans (i.e., the "step-van" city delivery type of vehicle 
that permits a person to enter the vehicle without 
stooping) from Standards Nos. 201, 203 and 204. 
In the case of Standard No. 201, they argued that 
this type of vehicle frequently has none of the com- 
ponents covered by the standard, such as arm 
rests, sun visors and instrument panels to the right 
of the steering assembly. However, those vehicles 
do have an instrument panel in front of the driver 
and some walk-in vans do have a front passenger 
seat and an instrument panel in front of that seat 
which may be struck by an occupant during a 
crash. Applying Standard No. 201 to those vehicles 
will require the instrument panel to be padded to 
cushion occupant impacts. Based on the proven 
effectiveness of Standard No. 201 in passenger 
cars, the agency is extending the performance 
requirements of the standard to include walk-in 
vans and MPV's. 

The manufacturers argued that walk-in vans 
should be exempt from Standards Nos. 203 and 
204 also. They said that the driver steering 
assembly configuration found in walk-in vans 
makes it improbable that compliance with the 
standard will reduce drivers' injuries. They noted 
that the steering column is mounted in those 
vehicles at an angle of 55-60 degrees, compared to 
the mounting angle of 30 degrees found in conven- 
tional trucks, and the columns in walk-in vans 
move upward rather than rearward in a crash. The 
manufacturers also argued that these vehicles are 
generally used in urban areas, where there is more 



slow speed traffic than in rural areas. They pointed 
out that because of these factors, the agency has 
previously exempted walk-in vans from Standards 
Nos. 212-76, Windshield Retenticm, and 219-75, 
Windshields Zone Intrusion. The agency agrees 
that current energy absorbing steering column 
designs probably would provide little, if any, pro- 
tection in walk-in vans because of their uniques 
driver/ steering column configuration, and thus is 
exempting walk-in vans for the present. 

Belts in Forward Control Vehicles 

Although they did not object to requiring lap- 
shoulder belts in forward control vehicles as pro- 
posed in the agency's November 9, 1978 notice, 
several manufacturers and the MVMA objected to 
what they interpreted as a conflict between the 
agency's proposal and the current requirements of 
Standard No. 208, Occupant Crash Protection. 
They argued that the agency's proposal not only 
would require lap and shoulder belts in forward 
control vehicles, but would also require such belts 
in open-body vehicles, convertibles and walk-in 
vans, which currently only have to have lap belts. 
The agency's proposal was directed only toward 
forward control vehicles and was meant to 
supersede the current requirements for those 
vehicles set in Standard No. 208. For organiza- 
tional simplicity, the agency is making a technical 
amendment to Standard No. 208 so that all belt 
requirements are centralized in that standard. The 
amendment only adopts the proposed change to 
the forward control vehicle belt requirements. It 
does not change the current belt requirements for 
open-body vehicles, convertibles and walk-in vans. 

MVMA requested the agency to require lap and 
shoulder belts in forward control vehicles for only 
one model year. M\^A did not provide any 
justification for that request. NHTSA believes that 
the important protection of lap and shoulder belts 
should be available to all forward control vehicles 
manufactured on or after September 1, 1981, and 
declines to adopt the MVMA request. 

Upgrading of Standard 

In their comments, the Center for Auto Safety 
and the Insurance Institute for Highway Safety 
renewed their requests that the agency set new 
performance requirements for Standard No. 203 to 
provide additional protection in angular impacts. 
The agency has conducted some preliminarj- 
testing to determine what additional requirements 



PART 571; S 201-PRE-7 



may be appropriate to increase protection in 
angular impacts. In additional, the agency's 
National Center for Statistics and Analysis has 
recently begun a special study to collect accident 
data on 1973 and later model vehicles to gather 
additional information on the effectiveness of 
energy absorbing steering assemblies in angular 
and other crashes. Based on that data, NHTSA 
will make a determination of what further changes 
are needed in the standard. 

The American Automobile Association asked the 
agency to delay application of Standard No. 203 
until upgraded performance requirements are 
developed. However, because the agency does not 
want to delay providing the occupants of light 
trucks, buses and MPV's with the safety benefits 
of Standard No. 203, the agency is extending the 
standards to those vehicles while it continues to 
consider the feasibility of additional performance 
requirements. 

NHTSA is also considering possible additional 
requirements for Standard No. 201. The agency 
has scheduled a meeting for December 11, 1979, so 
that the public can present its views and ideas on 
ways of improving protection for children invilved 
in vehicle collisions. In the September 4, 1979, 
notice announcing the meeting, the agency 
specifically asked for comments on possible 
improvements to the interior padding of vehicles to 
provide additional protection for children (44 FR 
51623). 

Heavy Trucks 

In the November 9, 1978 notice, NHTSA 
announced that it was evaluating whether to 
extend the applicability of Standards Nos. 201, 203 
and 204 to heavy trucks (i.e., trucks with a GVWR 
of more than 10,000 pounds) and solicited 
commens on appropriate performance 
requirements for those vehicles. In their com- 
ments, the Motor Vehicle Manufacturers Associa- 
tion, Freightliner and International Harvester all 
opposed an extension of the standards to trucks 
with a GVWR greater than 10,000 pounds, arguing 
that there is no data showing a safety need for 
applying the standards to those vehicles. They also 
argued that because of the size and weight of heavy 
trucks, occupants in these vehicles do not 
experience the same energy transfers in a crash 
than passenger car occupants experience and thus 
theoretically should incur fewer or less severe 



injuries. At the agency's recent meeting on heavy 
truck safety, several participants provided in- 
formation on the need for greater crash protection 
for drivers of heavy trucks. NHTSA is currently 
analyzing that information to determine what 
additional heavy truck reguylatory action may be 
needed. 

Miscellaneous Comments 

MVMA pointed out that Standard No. 201 
currently requires two sun visors in a vehicle and 
requested that a second visor not be required if 
there is no front passenger seat. NHTSA agrees 
that such a change is appropriate and has made the 
necessary amendment to the standard. 

Jeep Corp. objected to the application of 
Standard No. 201 to open-body MPV's, arguing 
that for Jeep to locate padding in the expected 
head impact area it would have to raise its padding 
or lower its seat, both of which it claimed would 
interfere with the driver's forward visibility. 
Jeep's comment apprars to reflect a misunder- 
standing of Standard No. 201. The performance 
requirements of the standard only apply to areas of 
the instrument panel that are within the head 
impact area of each designated seating position. 
(The head impact area is the portion of the 
vehicle's interior that can be contacted by a head- 
form representing an occupant's head.) Thus, if a 
portion of Jeep's vehicle instrument panel is not 
within the head impact area, it does not have to 
comply. For protions of the panel that are within 
the head impact area, Jeep can make structural 
changes to the instrument panel to meet Standard 
No. 201 without adding additional padding. 
Therefore, Jeep's requested exemption for all 
open-body vehicles is denied. 

One final stage manufactuere, Boyertown Auto 
Body Works, asked NHTSA whether its driver 
side instrument panel was within the exceptions to 
Standard No. 201 and, if not, sought to have its in- 
strument panel constured to be a console assembly, 
which is exempt from the standard. Such an inter- 
pretation is not acceptable since Boyertown clearly 
labels the area in question as an instrument panel 
in its engineering drawings. However, according 
to the engineering drawing provided by Boyer- 
town, the limited section on teh instrument panel 
of concern to Boyertown is within the area 
exempted by S3. 1.1(d) of the standard. That 
section provides that the area of the interior 
immediately forward of the steering column is 
exempt from the standard. 



PART 571; S 201-PRE-8 



Costs and Leadtime 

NHTSA has considered the economic and other 
impacts of this final rule and determined that they 
are not significant within the meaning of 
Executive Order 12044 and the Department of 
Transportation's policies and procedures for 
implementing that order. The agency's assessment 
of the benefits and economic consequences of this 
proposal are contained in a regulatory evaluation 
which has been places in the public docket. As 
explained previously, copies of the regulatory 
evaluation can be obtained by writing NHTSA' s 
docket section at the address given in the begin- 
ning of this final rule. 

As previously detailed in this notice, the agency 
has examined the effectiveness of Standards Nos. 
201, 203 and 204 in passenger cars and concluded 
that those standards have brought about a substan- 
tial reduction in overall injuries occurring to the 
passengers in those vehicles. Because they share 
the same driving environment as occupants in 
passenger cars, occupants in light trucks, buses 
and MPV's face a similar risk of injury posed by 
hazardous instrument panels and rigid steering 
columns. Based on its evaluation of the effec- 
tiveness of Standards Nos. 201, 203 and 204 in 
passenger cars, the agency has concluded that 
applying those standards to light trucks, buses and 
MPV's can result in a reduction of 120 to 240 
fatalities and 4,400 to 8,900 serious injuries per 
year when all those vehicles comply with the 
standards. 

The agency's cost estimate for meeting 
Standards Nos. 201, 203 and 204 in light trucks, 
buses and MPV's take into account that many 
manufacturers have equipped some of their 
vehicles with components designed to meet the 
performance requirements of the standards. Those 
components may need little or no redesigning to 
fully comply with the standards. For example, 
American Motors, Chrysler, Ford, General 
Motors, International Harvester and Volkswagen 
commented that some, if not all, of their vehicles 
currently have components designed to comply 
with the standards or they will install such com- 
ponents in some of their vehicles by the 1981 model 
year. 

Only two manufacturers, Nissan and Ford, pro- 
vided any information about the costs associated 
with complying with the standards. Nissan said 



that the cost associated with complying with all 
three standards was $30. Ford estimated the cost 
for compliance with Standard No. 201 as $10 per 
vehicle; based on preliminary design assumptions, 
Ford put the cost of complying with Standards 
Nos. 203 and 204 in its van-type trucks, buses and 
MPV's at $120 per vehicle. 

To provide the agency with additional informa- 
tion about the estimated costs of complying with 
the three standards, NHTSA contracted with the 
John Z. DeLorean Corp. to evaluate current 
vehicles and determine what changes would be 
needed to bring the vehicles into compliance. Bases 
on its review of current foreign and domestic light 
trucks, buses and MPV's, DeLorean concluded 
that the total cost of compHance with the three 
standards would add a sales weighted average of 
$16 to the retail price of those vehicles. The 
DeLorean study reported that the vehicles requir- 
ing the most changes to meet Standards Nos. 201, 
203 and 204 were van-type trucks, buses and 
MPV's made by GM and Ford. DeLorean 
estimated that GM and Ford van-types vehicles 
would require a $27 increase in consumer price to 
comply with Standards Nos. 203 and 204 and a 
price increase ranging between $6 and $15 to 
comply with Standard No. 201. The agency 
believes that the substantial difference between 
DeLorean's and Ford's estimate of the cost of 
compliance with Standards Nos. 203 and 204 may 
be due to Ford's overestimate of the anticipated 
changes needed in the vehicles based on its 
preliminary' design asssumptions. 

The agency's November 1978 notice proposed an 
effective date of September 1, 1980, for Standard 
No. 201 for all vehicles and for Standards Nos. 203 
and 204 for nonforward control vehicles. An effec- 
tive date of September 1, 1981, was proposed for 
Standards Nos. 203 and 204 for forward control 
vehicles to allow manufacturers additional time to 
make the necessary changes in those vehicles. In 
their comments on Standard 201, Chrysler and 
Ford said they could meet the standard in all their 
vehicles by the proposed effective date. Nissan, 
Toyo Kogyo and International Harvester (IH) 
requested from 18 to 24 months leadtime. General 
Motors requested 2V2 years' leadtime and 
American Motors requested 3 years. As a part of 
its NHTSA-funded study of the costs of complying 
with the standard, the DeLorean Corp. also 
examined the leadtime necessary to comply with 



PART 571; S 201-PRE-9 



the standard, the DeLorean Corp. also examined 
the leadtime necessary to comply with the stan- 
dards. For Standard No. 201, the DeLorean study 
concluded that only one year was needed for all 
vehicles except van-type trucks, buses and MPV's 
manufactured by Chrysler and GM, which needed 
two years. 

For Standards Nos. 203 and 204, Chrysler said 
that all its vehicles, except its incomplete forward 
control van-type vehicles, can comply by 
September 1, 1980. Chrysler did not provide an 
estimate of leadtime needed for its incomplete 
forward control vans. Nissan, Toyo Kogo and IH 
requested from 18 to 24 months leadtime. Ford 
said Its 1980 model year F-series trucks and 
Bronco models would comply with the standards 
and the Courier truck chassis cab imported by Ford 
would comply by September 1, 1981. Ford 
requested until September 1, 1982, for its van-type 
trucks, buses and MPV's. General Motors 
requested 2V2 years for all its vehicles and 
American Motors requested three years. 

The DeLorean study concluded that 18-24 
months of leadtime was needed for all models, 
except those made by Ford, which would require 
three years. DeLorean made its estimate of lead- 



time for Ford based on an assumption that Ford 
would need extra steering assembly tooling 
facilities. However, since Ford plans to introduce 
complying components on its 1980 model F series 
trucks and Bronco models, Ford has apparently 
developed the needed tooling capacity. 

Based on its analysis of the DeLorean study and 
of the industry's comments, NHTSA concludes 
that setting an effective date of September 1, 
1981, will allow sufficient time for all manufac- 
turers to comply with the standards. This action 
provides an additional year for all light trucks, 
buses and MPV's to meet Standard No. 201 and for 
nonforward control vehicles to meet Standard No. 
201 and for nonforward control vehicles to meet 
Standards Nos. 203 and 204. 

The principal authors of this notice are William 
Smith, Office of Vehicle Safety Standards, and 
Stephen Oesch, Office of Chief Counsel. 

Issued on November 20, 1979. 

Joan Claybrook 
Administrator 

44 F.R. 68470 
November 29, 1979 



PART 571; S 201-PRE-lO 



MOTOR VEHICLE SAFETY STANDARD NO. 201 
Occupant Protection in Interior Impact— Passenger Cars 



51. Purpose and scope. This standard 
specifies requirements to afford impact protection 
for occupants. 

52. Application. This standard applies to 
passenger cars and to multipurpose passenger 
vehicles, trucks and buses with a GVWR of 10,000 
pounds or less. 

53. Requirements for passenger cars and for 
trucl(s, buses and multipurpose passenger vehicles 
with a GVWR of 10,000 pounds or less manufactured 
on or after September 1, 1981. 

S3.1 Instrument panels. Except as provided in 
S3. 1 . 1 , when that area of the instrument panel that 
is within the head impact area is impacted in accor- 
dance with S3. 1.2 by a 15 pound, 6.5 inch diameter 
head form at a relative velocity of 15 miles per 
hour, the deceleration of the head form shall not 
exceed 80g continuously for more than 3 
milliseconds. 

53.1.1 The requirements of S3.1 do not apply 
to- 

(a) Console assemblies; 

(b) Areas less than 5 inches inboard from the 
juncture of the instrument panel attachment to the 
body side inner structure; 

(c) Areas closer to the windshield juncture than 
those statically contactable by the head form with 
the windshield in place; 

(d) Areas outboard of any point of tangency on 
the instrument panel of a 6.5 inch diameter head 
form tangent to and inboard of a vertical 
longitudinal plane tangent to the inboard edge of 
the steering wheel; or 

(e) Areas below any point at which a vertical line 
is tangent to the rearmost surface of the panel. 

53.1.2 Demonstration procedures. Tests shall 
be performed as described in Society of 
Automotive Engineers Recommended Practice 
J921, "Instrument Panel Laboratory Impact Test 
Procedure," June 1965, using the specified in- 
strumentation or instrumentation that meets the 



performance requirements specified in Society of 
Automotive Engineers Recommended Practice 
J977, "Instrumentation for Laboratory Impact 
Tests," November 1966, except that— 

(a) The origin of the line tangent to the instru- 
ment panel surface shall be a point on a transverse 
horizontal line through a point 5 inches horizontally 
forward of the seating reference point of the front 
outboard passenger designated seating position, 
displaced vertically an amount equal to the rise 
which results from a 5 inch forward adjustment of 
the seat or 0.75 inches; and 

(b) Direction of impact shall be either— 

(1) In a vertical plane parallel to the vehicle 
longitudinal axis; or 

(2) In a plane normal to the surface at the 
point of contact. 

S3.2 Seat Backs. Except as provided in 
S3.2.1, when that area of the seat back that is 
within the head impact area is impacted in accor- 
dance with S3. 2. 2 by a 15 pound, 6.5 inch diameter 
head form at a relative velocity of 15 miles per 
hour, the deceleration of the head form shall not 
exceed 80g continuously for more than 3 
milliseconds. 

53.2.1 The requirements of S3.2 do not apply to 
rearmost, side-facing, back-to-back, folding 
auxiliary jump, and temporary seats. 

53.2.2 Demonstration procedures. Tests shall 
be performed as described in Society of 
Automotive Engineers Recommended Practice 
J921, "Instrument Panel Laboratory Impact Test 
Procedure," June 1965, using the specified 
instrumentation or instrumentation that meets the 
performance requirements specified in Society of 
Automotive Engineers Recommended Practice 
J977, "Instrumentation for Laboratory Impact 
Tests," November 1966, except that— 

(a) The origin of the line tangent to the upper- 
most seat back frame component shall be a point 



PART 571; S 201-1 



on a transverse horizontal line through the seating 
reference point of the right rear designated 
seating position, with adjustable forward seats in 
their rearmost design driving position and 
reclinable forward seat backs in their nominal 
design driving position; 

(b) The direction of impact shall be either— 

(1) In a vertical plane parallel to the vehicle 
longitudinal axis; or 

(2) In a plane normal to the surface at the 
point of contact; 

(c) For seats without head restraints installed, 
tests shall be performed for each individual split or 
bucket seats back at points within 4.0 inches left 
and right of its centerline, and for each bench seat 
back between points 4.0 inches outboard of the 
centerline of each outboard designated seating 
position; 

(d) For seats having head restraints installed, 
each test shall be conducted with the head 
restraint in place at its lowest adjusted position, at 
a point on the head restraint centerline; and 

(e) For a seat that is installed in more than one 
body style, tests conducted at the fore and aft 
extremes identified by application of subparagraph 
(a) shall be deemed to have demonstrated all 
intermediate conditions. 

S3.3 Interior compartment doors. Each interior 
compartment door assembly located in an instru- 
ment panel, console assembly, seat back, or side 
panel adjacent to a designated seating position 
shall remain closed when tested in accordance with 
either S3.31(a) and S3.3.1(b) or S3.3.1(a) and 
S3. 3. 1(c). Additionally, any interior compartment 
door located in an instrument panel or seat back 
shall remain closed when the instrument panel or 
seat back is tested in accordance with S3.1 and 
S3. 2. All interior compartment door assemblies 
with a locking device must be tested with the 
locking device in an unlocked position. 

S3.3.1 Demonstration procedures. 

(a) Subject the interior compartment door latch 
system to an inertia load of lOg in a horizontal 
transverse direction and an inertia load of lOg in a 
vertical direction in accordance with the procedure 
described in section 5 of SAE Recommended 
Pactice J839b, "Passenger Car Side Door Latch 
Systems," May 1965, or an approved equivalent. 



(b) Impact the vehicle perpendicularly into a fixed 
collision barrier at a forward longitudinal velocity of 
30 miles per hour. 

(c) Subject the interior compartment door latch 
system to a horizontal inertia load of 30g in a 
longitudinal direction in accordance with the pro- 
cedure described in section 5 of SAE Recommended 
Practice J839b, "Passenger Car Side Door Latch 
Systems," May 1965 or an approved equivalent. 

53.4 Sun visors. 

53.4.1 A sun visor that is constructed of or 
covered with energy-absorbing material shall be 
provided for each front outboard designated 
seating position. 

53.4.2 Each sun visor mounting shall present 
no rigid material edge radius of less than 0.125 
inch that is statically contactable by a spherical 6.5 
inch diameter head form. 

53.5 Armrests. 

53.5.1 General. Each installed armrest shall 
conform to at least one of the following: 

(a) It shall be constructed with energyabsorbing 
material and shall deflect or collapse laterally at 
least 2 inches without permitting contact with any 
underlying rigid material. 

(b) It shall be constructed with energy-absorbing 
material that deflects or collapses to within 1.25 
inches of a rigid test panel surface without permit- 
ting contact with any rigid material. Any rigid 
material between 0.5 and 1.25 inches from the panel 
surface shall have a minimum vertical height of not 
less than 1 inch. 

(c) Along not less than 2 continuous inches of its 
length, the armrest shall, when measured vertically 
in side elevation, provide at least 2 inches of 
coverage within the pelvic impact area. 

53.5.2 Folding armrests. Each armrest that 
folds into the seat back or between two seat backs 
shall either— 

(a) Meet the requirement of S3. 5.1; or 

(b) Be constructed of or covered with energy- 
absorbing material. 



33 F.R. 15794 
October 25, 1968 



PART 571; S 201-2 



EffMtIv*: January I, 19A9 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 202 

Head Restraints — Passenger Cars 
(Docket No. 8) 



A proposal to amend §371.21 of Part 371, 
Federal Motor Vehicle Safety Standards, by 
adding a new standard. Head Restraints — Pas- 
senger Cars; was published in the Federal Reg- 
ister on December 28, 1967 (32 F.R. 20865). 

Interested persons have been afforded an op- 
portunity to participate in the making of the 
amendment. 

Several comments requested that the use of a 
50th percentile adult male manikin be permitted 
in demonstrating compliance with the Standard. 
The Administration feels that a 50th percentile 
manikin is not representative of a large enough 
percentage of the public, but recognizes that cer- 
tain modifications to a 50th percentile manikin 
may result in a suitable test device. Therefore, 
the Standard has been modified to permit use 
of an approved equivalent test device. 

A comment from an equipment manufacturer 
and an equipment manufacturers' association as- 
serted that the Standard should not require that 
motor vehicle manufacturers provide head re- 
straints at the time of vehicle manufacture, but 
that each customer should be free to equip his 
vehicle with head restraints of his own choice, 
maintaining that the installation of head re- 
straints is a relatively simple matter and that 
there appears to be virtually no technological 
advantage in requiring factory installation. The 
Administration has determined that safety dic- 
tates that head restraints be provided on all 
passenger cars manufactured on or after January 
1, 1969, and that a head restraint standard that 
merely specified performance requirements for 
head restraint equipment would not insure that 
all passenger cars would be so equipped, and 
would not, therefore, meet the need for safety. 
Furthermore, the Administration has determined 
that the performance of a head restraint is de- 



pendent upon the strength of the structure of 
the seat to which it is attached, as well as the 
compatibility of the head restraint with its 
anchorage to the seat structure. 

Some of the comments expressed concern that 
the proposed Standard would exclude the use of 
head restraints that are integral with the seat 
back. The Administration did not intend to 
imply that "add-on" head restraint devices are 
the only available means of providing appro- 
priate levels of protection. Such protection may 
be achieved by the use of a restraint system that 
is integral with the seat back. 

Some comments noted that when testing head 
restraints that are adjustable to a height of more 
than 27.5 inches above the seating reference point, 
the load would not be applied to the appropriate 
portion of the head restraint. To provide the 
necessary flexibility, the Standard has been modi- 
fied to specify that the point of load application 
and the point of width measurement be deter- 
mined relative to the top of the head restraint 
rather than the seating reference point. 

Some comments stated that the 8g perform- 
ance requirement would be incomplete without 
the inclusion of a time duration requirement. 
The Administration has concluded that a mini- 
mum time duration of 80 milliseconds is appro- 
priate and the Standard has been so modified. 

Some comments requested that the location of 
the head restraint relative to the torso line be 
measured without a load being applied to the 
head restraint. The Administration feels that 
this measurement would be unrealistic and, 
therefore, the Standard requires that the meas- 
urement be taken during the application of the 
132-pound initial load. 

Many comments requested a more precise de- 
scription of the method to be used in locating 



PART 571; S 202— PRE 1 



t*Mtlv«: I 



the test device's r«fereno« line and torso refer- 
ence line. Therefore, the Standard has been 
modified to provide the necessary clarification. 

Some comments claimed that lead time would 
be a problem; however, the Administration be- 
lieves that the need to protect the public from 
neck injury outweighs the possible lead time 
problems. 

Several comments requested clarification of the 
term "approved representation of a human ar- 
ticulated neck structure." "Approved" is defined 
in § 371.3(b) as "approved by the Secretary." 
The Secretary would appwove the neck structure 
of a test device if it could be demonstrated by 
technical test data that the artn^lation of the 
neck structure represented that of a human neck. 
Approval could only be given to a structure 
sufficiently described in performance parameters 
to ensure reliable and reproducible test data. 



In consideration of the foregoing, § 371.21 of 
Part 371, Federal Motor Vehicle Safety Stand- 
ards, is amended by adding Standard No. 202 . . . 
Effective January 1, 1969. 

(Sees. 103 and 119 of the National Traffic and 
Motor Vehicle Safety Act of 1966; 15 U.S.C. 
1392, 1407; and the delegation of authority of 
Mar. 31, 1967, 32 F.R. .5606; as amended Apr. 6, 
1967, 32 F.R. 6495; July 27, 1967, 32 F.R. 11276; 
Oct. 11, 1967, 32 F.R. 14277; Nov. 8, 1967, 32 
F.R. 15710, and Feb. 8, 1968) 

Issued in Washington, D.C., on February 12, 
1968. 

Lowell K. Bridwell, 

Federal Highway Administrator 

33 F.R. 2945 
February 14, 1968 



i 



i 

I 



PART 571 ; S 202— PRE 2 



i 



UNcMv*: JaniMry 1, 1969 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 202 

Head Restraints — Passenger Cars 
(Docket No. t) 



Motor Vehicle Safety Standard No. 202, issued 
February 12, 1968, and published in the Federal 
Register February 14, 1968 (33 F.R. 2945), speci- 
fies requirements for head restraints to reduce 
the frequency and severity of neck injury in 
rear-end and other collisions to occupants of 
passenger cars manufactured after January I, 
1969. 

Pursuant to 23 CFR 216.35 (32 F.R. 15818), 
interested persons could petition the Federal 
Highway Administrator for reconsideration on 
or before March 15, 1968. 

Several petitioners questioned the 80 milli- 
second duration requirement of the 8g dynamic 
test on the grounds that it imposes a more severe 
load on the seat back than is required in Motor 
Vehicle Safety Standard No. 207, Anchorage of 
Seats — Passenger Cars. The Administrator has 
determined that the demonstration procedure 
should be revised to incorporate a half-sine wave 
■cceleration pulse shape with an amplitude of 8g 
and a base (duration) of 80 milliseconds. This 
revised loading is closer to actual crash condi- 
tions, and is more consistent with existing seat 
strength requirements. The demonstration pro- 
cedure has been revised to include the half-sine 
wave pulse shape. 

Several petitioners questioned the method for 
establishing the displaced torso line for the static 
test on the grounds that it did not take into 
account the compression of the seat back cushion 
by the torso under load. The Administrator has 
determined that the Standard should be revised 
to take into account seat back cushion compres- 
sion in establishing the displaced torso line, and 
the demonstration procedure has been revised 
accordingly. 



One petitioner questioned the procedure out- 
lined for establishing the dummy reference line 
for the dynamic test. The procedure made use 
of the torso line of the 95th percentile dummy 
or test device and there is no commonly accepted 
definition of this torso line. The Administrator 
has revised the procedure for establishing dummy 
torso reference lines to make use of the SAE 
two-dimensional manikin, with its torso line 
established in accordance with SAE Aerospace- - 
Automotive Drawing Standards. 

One petitioner questioned the requirement that 
a spherical head form be used to apply the static 
load because tests have shown that this head 
form tends to slip under the foundation structure 
of the head restraint, thus showing an unrealistic 
loss of load. The Administrator has revised the 
demonstration procedure to include a cylindrical 
head form as an alternative. 

One petitioner requested that the static load 
requirement of 200 pounds for head restraints 
adjusted to a height of 27.5 inches be changed 
to an equivalent moment about the seating refer- 
ence point. This would permit the manufacturer 
who has a head restraint which adjusts higher 
than 27.5 inches to subject his head restraint to 
less than a 200 pound static load. This petition 
is denied. The Administrator has determined 
that the 200 pound static load should remain in 
the Standard to ensure that all head restraints 
sustain this load to meet the needs of safety. 

Since this amendment provides clarification, 
relieves a restriction, and imposes no additional 
burden, notice and public procedure are unnec- 
essary. 

In consideration of the foregoing, § 371.21 of 
Part 371, Federal Motor Vehicle Safety Standard 
No. 202, which becomes effective January 1, 1969, 



PART 571; S 202— PRE 3 



Effacllv*: January 1, 1969 

is amended by revising sections 5.1 and 5.2 (re- Issued in Washington, D.C., on April 11, 1968. 

lating to the demonstration procedures). . . . 

(Sees. 103, 119, National Traffic and Motor Lowell K. Bridwell, 

Safety Act of 1966 (15 U.S.C. 1392, 1407); Federal Highway Administrator 
delegation of authority of March 31, 1967 (32 

F.R. 5606), as amended April 11, 1968 (33 F.R. 33 F.R. 5793 

5803)) April 16, 1968 



PART 571; S 202— PRE 4 



Elhctlva: January 1, 1969 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 202 

Head Restraints — Passenger Cars 
(Docket No. 8) 



Motor Vehicle Safety Standard No. 202 (33 
F.R. 2945), as amended (33 F.R. 5793), specifies 
requirements for head restraints to reduce the 
frequency and severity of neck injury in rear- 
end and other collisions to occupants of passenger 
cars manufactured after January 1, 1969. 

Paragraph S4 (b)(2) of the Standard provides 
that a head restraint qualifying under the static 
procedure shall have a lateral width of 10 inches 
for use with bench-type seats and 6.75 inches for 
use with individual type seats when measured 
2.5 inches belo-v the top of the head restraint. 

One manufacturer has petitioned the Admin- 
istrator for reconsideration of the method by 
which the lateral width of the head restraint is 
to be measured. The petitioner requests that the 
Standard be revised to permit the width to be 
measured either 2.5 inches below the top of the 
head restraint of 25 inches above the seating 
reference point. 

Measurement of width 2.5 inches below the top 
of the head restraint may present possible diffi- 
culties for manufacturers of vehicles with head 
restraints which are integrated into the seat back. 
These manufacturers may elect to exceed the 
minimum required height of 27.5 inches to ac- 
commodate tall occupants and taper the top por- 
tion of the head restraint to provide minimum 
visibility restriction. In this case, the head re- 
straint, when measured 2.5 inches below the top, 
might meet the minimum width requirement. 

The Administrator has determined that the 
procedure for measuring head restraint lateral 
width should be revised since it is in the public 
interest to encourage the additional protection 
offered by seat backs higher than the minimum 
height requirement of this Standard. Accord- 
ingly, the Standard is being amended to permit 



measurement of head restraint width either 2.5 
inches below the top of the head restraint or 25 
inches above the seating reference point. 

Paragraph S5.1(c) of the Standard provides 
that the magnitude of the acceleration curve for 
the dynamic test shall not be less than that of a 
half-sine wave having the amplitude of 8g and 
a duration of 80 milliseconds not more than 20% 
above the half-sine wave. 

One manufacturer has requested an interpre- 
tation of the term "not more than 20% above the 
half-sine wave." 

It is necessary that a test tolerance be allowed 
because of equipment variances. However, the 
tolerance must be properly limited to prevent 
very severe accelerations which might fail the 
seat back without properly testing the head re- 
straint. The intent of the "20%" limitation was 
to establish a half-sine wave upper limit curve 
having an amplitude of 9.6g and a duration of 
96 milliseconds. 

Accordingly, the Standard is being amended 
to require that the magnitude of the acceleration 
curve be not more than that of a half-sine wave 
curve having an amplitude of 9.6g and a duration 
of 96 milliseconds. In addition, the equation for 
the lower limit curve is being deleted since it 
imposes an unnecessary restriction on the lateral 
location of the curve. By removing the equation, 
the limit curves can then be moved laterally with 
respect to each other to allow for normal test 
variances. 

Since these amendments provide clarification 
and an alternate means of compliance, relieve 
restrictions, and impose no additional burden, 1 
find that for good cause shown notice and public 
procedure are unnecessary, and that an effective 



PART 571: S 202— PRE 5 



EKmMv*: January 1, 1969 I 

i 

date for these amendments of less than 180 days lations of the Office of the Secretary of Trans- j 

is in the public interest. portation (49 CFR 1.4(c)). A 

In consideration of the foregoing, Section ^^^^^ i„ Washington, D.C., on October 3, I 

371.21 of Part 371, Federal Motor Vehicle Safety ^ggg ^' 
Standard No. 202, as amended, is further amended 

effective January 1, 1969 t ii ir ti ^,^ ii I 

These amendments are made under the author- }f,\ ^- ^''i°^«4' , . . ; 

ity of Sections 103 and 119 of the National Traffic ^^^^^••'^^ Highway Admmistrator , 

and Motor Vehicle Safety Act of 1966 (15 U.S.C. j 

1392, 1407) and the delegation of authority con- 33 F.R. 15065 | 

tained in Section 1.4(c) of Part 1 of the Regu- October 9, 1968 \ 



i 



PART 571; S 202— PRE 6 ^ 



MOTOR VEHICLE SAFETY STANDARD NO. 202 
Head Restraints— Passenger Cars 



51. Purpose and Scope. This standard speci- 
fies requirements for head restraints to reduce 
the frequency and severity of neck injury in 
rear-end and other collisions. 

52. Application. This standard applies to pas- 
senger cars. 

53. Definitions. "Head restraint" means a de- 
vice that limits rearward angular displacement 
of the occupant's head relative to his torso line. 

54. Requirements. A head restraint that con- 
forms to either (a) or (b) shall be provided at 
each outboard front designated seating position— 

(a) It shall, when tested in accordance with 
S5.1, during a forward acceleration of at least 
8g on the seat supporting structure, limit rear- 
ward angular displacement of the head refer- 
ence line to 45° from the torso reference line; or 

(b) It shall, when adjusted to its fully ex- 
tended design position, conform to each of the 
following— 

(1) When measured parallel to torso line, 
the top of the head restraint shall not be less 
than 27.5 inches above the seating reference 
point; 

(2) When measured either 2.5 inches be- 
low the top of the head restraint, or 25 inches 
above the seating reference point, the lateral 
width of the head restraint shall be not less 
than— 

(i) 10 inches for use with bench-type seats; 
and 

(ii) 6.75 inches for use with individual 
seats; 

(3) When tested in accordance with S5.2, 
the rearmost portion of the head form shall not 
be displaced to more than 4 inches perpendicu- 
larly rearward of the displaced entended torso 
reference line during the application of the 
load specified in S5.2(c); and 



(4) When tested in accordance with S5.2, 
the head restraint shall withstand an increas- 
ing load until one of the following occurs— 
(i) Failure of the seat or seat back; or 
(ii) Application of a load of 200 pounds. 

S5. Demonstration Procedures. 

S5.1 Compliance with S.4(a) shall be demon- 
strated in accordance with the following with 
the head restraint in its fully extended design 
position: 

(a) On the exterior profile of the head and 
torso of a dummy having the weight and seated 
height of a 95th percentile adult male with an 
approved representation of a human, articulated 
neck structure, or an approved equivalent test 
device, establish reference lines by the following 
method: 

(1) Position the dummy's back on a hori- 
zontal flat surface with the lumbar joint in a 
straight line. 

(2) Rotate the head of the dummy rear- 
ward until the back of the head contacts the 
same horizontal surface in (1). 

(3) Position the SAE J-826 two-dimen- 
sional manikin's back against the flat surface 
in (1), alongside the dummy with the h-point 
of the manikin aligned with the h-point of the 
dummy. 

(4) Establish the torso line of the manikin 
as defined in SAE Aerospace-Automotive 
Drawing Standards, Sec. 2.3.6, P. El. 01, 
September 1963. 

(5) Establish the dummy torso reference 
line by superimposing the torso line of the 
manikin on the torso of the dummy. 

(6) Establish the head reference line by ex- 
tending the dummy torso reference line onto 
the head. 



PART 571; S 202-1 



(b) At each designated seating position having 
a head restraint, place the dummy, snugly re- 
strained by a Type 1 seat belt, in the manufac- 
turer's recommended design seated position. 

(c) During a forward accleration applied 
to the structure supporting the seat as described 
below, measure the maximum rearward angular 
displacement between the dummy torso reference 
line and the head reference line. When graph- 
ically depicted, the magnitude of the acceleration 
curve shall not be less than that of a half-sine 
wave having the amplitude of 8g and a duration 
of 80 milliseconds and not more than that of a 
half-sine wave curve having an amplitude of 
9.6g and a duration of 96 milliseconds. 

S5.2 Compliance with § 4.(b) shall be dem- 
onstrated in accordance with the following with 
the head restraint in its fully extended design 
position: 

(a) Place a test device, having the back pan 
dimensions and torso line, (centerline of the 
head room probe in full back position) of the 



three dimensional SAE J-826 manikin, at the 
manufacturer's recommended design seated po- 
sition. 

(b) Establish the displaced torso reference 
line by applying a rearward moment of 3300 in. 
lb. about the seating reference point to the seat 
back through the test device back pan located 
in (a). 

(c) After removing the back pan, using a 6.5 
inch diameter spherical head form or a cylindri- 
cal head form having a 6.5 inch diameter in 
plain view and a 6-inch height in profile view, 
apply, perpendicular to the displaced torso refer- 
ence line, a rearward initial load 2.5 inches below 
the top of the head restraint that will produce 
a 3300 in. lb. moment about the seating reference 
point. 

(d) Gradually increase this initial load to 
200 lbs. or until the seat or seat back fails, 
whichever occurs first. 

33 F.R. 15065 
October 9, 1968 



PART 571; S 202-2 



Effective: May 27, 1975 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 203 
Impact Protection from the Steering Control System 
(Docket No. 74-33; Notice 2) 



This notice amends Standard No. 203, Impact 
protection from the steering control system, 49 
CFR § 571.203, to exclude from its requirements 
some passenger cars which meet the frontal bar- 
rier crash requirements of Standard No. 208, 
Occupant crash protection, 49 CFR § ,571.208. 

The NHTSA proposed this exclusion of ve- 
hicles from the requirements of Standard No. 
203 at the request of General Motors, to permit 
development of an air cushion restraint system 
at the driver's position as a means of meeting 
the frontal barrier crash protection requirements 
(S5.1) of Standard No. 208 (39 F.R. 34062, Sep- 
tember 23, 1974). General Motoi-s sought the 
exclusion because its modification to the steering 
control system to incorporate the air cushion sys- 
tem and accept higher loads exerted during a 
crash makes conformity of the column with 
Standard No. 203 difficult and sometimes impos- 
sible. 

Comments were received from General Motors 
Corporation and Volvo of America Corporation, 
in support of the proposal. Renault. Inc., 
Peugeot, Inc., and Mercedes-Benz of North 
America, Inc., supported the proposal and sug- 
gested that the exception be extended to passive 
straint systems that incorporate seat belts. These 
comments argue that the use of passive belts will 
be high and that the protection offered by Stand- 
ard No. 203 would in nearly all cases be redun- 
dant to that of Standard No. 208. 

As a general matter, the NHTSA has main- 
tained that the redundant occupant crash protec- 
tion offered by standards (e.g.. Standard No. 212, 
Windshield retention) is justified for those sit- 
uations where the primary occupant crash pro- 
tection system fails, or multiple collisions occur. 



Redundant protection is particularly justified in 
tlie case of passive seat belts because of the 
greater likelihood that seat belt protection \v\\\ 
be rendered inoperative by an occupant than will 
crash-deployed protection. 

In this case, the NHTSA has made the limited 
determination that the redundant protection of- 
fered by Standard No. 203 is not justified where 
it directly interferes witli development of a more 
advanced, convenient, and etl'ective restraint sys- 
tem. In contrast, it is obHous that passive sys- 
tems which utilize belt assemblies do not require 
modifications of steering control systems and 
there is, therefore, no reason to sacrifice the re- 
dundant protection. These petitions to expand 
the scope of the proposed exception are accord- 
ingly denied. 

American ilotors Corporation has suggested 
that an exception not be granted in this case 
until future requirements of Standard No. 208 
are established, and that General Motors' devel- 
opmental work be undertaken on the basis of a 
temporary exemption under 49 CFR Part 555. 
This approach has not been adopted by the 
NHTSA. In light of the financial commitments 
that miglit be involved, this agency has con- 
cluded that General Motors is entitled to the 
assurance that tlieir developments on ad^•'anced 
Standard No. 208 systems will not be barred by 
Standard No. 203 in the future. 

In consideration of the foregoing, paragraph 
S3 (application) in Standard No. 203 (49 CFR 
§ 571.203) is amended 

Ejfecfive date: [30 days following date of 
publication of the amendment in the Federal 
Register^. Because this amendment relieves a 
restriction, it is found for good cause shown that 



PART 571; S 203— PRE 1 



Effective: May 27, 1975 



an effective date sooner than 180 days from tlie Issued on April 17, 1975. ' 

date of Its publication in the Federal Register I 

is in the public interest. jan^es g Gregory 1 

(Sec. 103, 119, Pub. L. 89-563. 80 Stat. 718 Administrator ^ 

(15 U.S.C. 1392, 1407); delegation of authority 40 F » ,7000 

at49CFRl.51.) a , I. , !.V; 

' April 24, 1975 



i 



PART 571; S 203— PRE 2 



t« 



PREAMBLE TO AMENDMENTS TO MOTOR VEHICLE SAFETY STANDARDS 

NO. 203 

Impact Protection for the Driver From the Steering Control System 
(Docket No. 78-116; Notice 2) 



ACTION: Final rule. 

SUMMARY: This notice amends Federal Motor 
Vehicle Safety Standards Nos. 201, 203 and 204 to 
extend their applicability to light trucks, buses and 
multipurpose passenger vehicles (MPV's). The 
notice is issued in response to the rising death and 
injury toll involving these vehicles and to petitions 
by the Center for Auto Safety and the Insurance 
Institute for Highway Safety requesting that these 
standards be extended to those vehicles. Applying 
these standards to light trucks, buses and MPV's 
will reduce occupant deaths and injuries in those 
vehicles by requiring the use of energy absorbing 
material on such interior components as the instru- 
ment panel and seat backs (Standard No. 201), by 
limiting the amount offeree that can be exerted on 
the driver's chest by the steering wheel in frontal 
crashes (Standard No. 203), and by limiting the 
rearward movement of the steering assembly in 
frontal crashes (Standard No. 204). 

EFFECTIVE DATE: The effective date for the 
extension of applicability of Standards Nos. 201, 
203 and 204 is September 1, 1981. 

ADDRESS: Petitions for reconsideration should 
refer to the docket number and be submitted to: 
Docket Section, Room 5108, National Highway 
Traffic Safety Administration, 400 Seventh Street, 
S.W., Washington, D.C. 20590. 

FOR FURTHER INFORMATION CONTACT: 

Mr. William Smith, Office of Vehicle Safety 
Standards, National Highway Traffic Safety 
Administration, 400 Seventh Street, S.W., 
Washington, D.C. 20590 (202-426-2242) 



SUPPLEMENTARY INFORMATION: This notice 
amends Standard No. 201, Occupant Protection in 
Interior Impact, and Standard No. 203, Impact 
Protection for the Driver From the Steering 
Control System, to extend the applicability of those 
standards to trucks, buses and multipurpose 
passenger vehicles (MPV's) with a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less. 
This notice also amends Standard No. 204, 
Steering Control Rearward Displacement, to 
extend its applicability to trucks, buses and MPV's 
with an unloaded vehicle weight of 4,000 pounds or 
less, instead of all trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less, as originally 
proposed in the agency's November 9, 1978, notice 
of proposed rulemaking (43 FR 52264). As explained 
below, the agency is initially limiting the extended 
applicability of Standard No. 204 while it studies 
methods for dealing with final-stage manufacturer 
certification difficulties. Similar possible problems 
with Standard No. 212-76, Windshield Mounting, 
and Standard No. 219-75, Windshield Zone Intru- 
sion, led the agency to propose changes in the 
testing procedures for those standards (44 FR 
45426). 

For the purposes of Standard No. 204, the agency 
has determined that these problems would not be 
encountered in applying the standard to vehicles 
with an unloaded vehicle weight of 4,000 pounds or 
less and testing them at their unloaded vehicle 
weight. Approximately 75 percent of the current 
sales of light trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less have an unloaded 
vehicle weight of 4,000 pounds or less. 

This final rule was preceded by a notice propos- 
ing the extension of the applicability of Standards 



PART 571; S 203-PRE-3 



Nos. 201, 203 and 204 in November 1978 (43 FR 
52264). Private citizens, safety organizations, 
manufacturers and a manufacturer trade associa- 
tion submitted comments on the proposal. NHTSA 
has considered all of those comments and the most 
significant ones are discussed below. 

Safety Need 
Citing the need to reduce the number of deaths 
and injuries in light trucks, buses and MPV's, the 
American Automobile Association, the Center for 
Auto Safety, the Insurance Institute for Highway 
Safety and State Farm Insurance Companies 
supported application of the standards to those 
vehicles. 

Although it did not object to extending the 
applicability of Standard Nos. 201, 203 and 204 to 
light trucks, buses and MPV's, General Motors 
argued that manufacturers should be given a 
longer lead time to comply with the standards 
because of the lack of urgent safety need. CM said 
that allowing a longer leadtime was desirable to 
ensure compliance, "without costly accelerated 
[design] programs." Using data from the agency's 
"Explanation of Rulemaking," CM said that light 
trucks, buses and MPV's have a fatality rate of 
22.4 fatalities per billion miles, compared with a 
rate of 25.3 fatalities per billion miles for 
passenger cars. The data GM used covers fatalities 
during 1977 in all model year vehicles. A new 
analysis done by NHTSA of 1977 fatalities, 
reported by the agency's Fatal Accident Reporting 
System, shows that although older model year 
light trucks, buses and MPV's may have had a 
lower fatality rate than passenger cars, beginning 
with the 1973 model year, the combined fatality 
rate for light trucks, buses and MPV's began 
surpassing that of passenger cars. The analysis 
shows that recent model year passenger cars have 
a considerably lower fatality rate than light trucks, 
buses and MPV's. (A copy of that analysis has been 
placed in the docket.) 

In addition to being higher than the combined 
fatality rate for all sizes of passenger cars, the 
combined fatality rate of light trucks, buses and 
MPV's is far higher than the rate for full-size 
passenger cars. Full-size cars are typically the 
safest of cars and many of them are comparable in 
size and weight to light trucks, buses and MPV's. 
In theory, occupants of larger and heavier vehicles, 
such as trucks, buses and MPV's, should experience 



less harmful crash forces, and thus presumably incur 
fewer or less severe injuries, than occupants of 
smaller lighter vehicles. Volkswagen has previously 
objected to a comparison of full-size passenger 
fatality rates with those for vans, arrguing that 
vans are comparable in weight to intermediate, not 
full-size passenger cars. Although the unloaded 
weight of vans and intermediate-size passenger 
cars may be comparable, vans have a higher gross 
vehicle weight rating which means that those 
vehicles can, in actual use, be loaded with substan- 
tially more weight than intermediate and even full- 
size passenger cars. 

Volkswagen also questioned the safety need for 
the proposed reulmaking because of the voluntary 
compliance by VW and some other companies with 
the standards. Although the voluntary effort by 
some companies is commendable, most manufac- 
turers do not comply with all of the standards in all 
of their vehicles. Some of the manufacturers who 
have taken steps to comply with the standard 
presumably were in part motivvated by prior 
NHTSA rulemaking notices proposing to apply 
Standards Nos. 201,203 and 204 to light trucks, 
buses and MPV's (35 FR 14936, 14936 and 16805). 
In the absence of a regulation, there is no 
assurance that non-complying manufacturers will 
produce complying vehicles and that manfacturers 
producing currently complying vehicles will 
continue to comply. Manufacturers who currently 
comply should experience only minor economic 
impacts, such as conducting certification tests as a 
result of compelling other manufacturers to 
comply. 

Effectiveness 

The Motor Vehicle Manufacturers Association 
(MVMA) questioned the potential effectiveness of 
Standards Nos. 201, 203 and 204. MVMA argue 
that a study done bySherman and Huelke of light 
truck and van accidents found that the standards 
would have little effect in those vehicles. However, 
a NHTSA analysis of the crashes reviewed by 
Sherman and Huelke found that a number of the 
crashes clearly edmonstrated the benefits of equip- 
ping light trucks and vans with energy absorbing 
instrument panels and steering columns and devices 
to limit the rearward displacement of the steering 
column. For example, Sherman and Huelke studied 
a 15-20 mph head-on crash of a 1976 Chevrolet 



PART 571; S 203-PRE-4 



pickup truck into a tree. The Chevrolet was equipped 
with a padded instrument panel, and energy- 
absorbing steering column and a device to limit the 
rearward displacement of the steering column. They 
reported, "the results of this case show that both of 
the major energy absorbing components appeared to 
have completely activated, both by the vehicle crash 
and driver impact, providing maximum benefit to the 
driver. Had this vehicle been one of the other vehicle 
cases discussed in this section, we feel that the in- 
juries sustained by the driver would have been much 
more severe." 

NHTSA believes further that the Sherman and 
Huelke study provides information indicating that 
there is a need for even more improvements in 
light trucks and vans, such as providing energy- 
absorbing padding for the lower instrument panel. 
The agency is studying the question of making 
appropriate changes in the performance 
requirements of the standards to require more pro- 
tection. However, NHTSA considers it important 
not to delay extending the current benefits of 
Standards Nos. 201, 203 and 204 while it reviews 
possible changes to the standards. 

MVMA also argued that a comparison of the 
injury experience of passenger car steering 
assemblies with the experience of steering 
assemblies in light trucks and vans shows that 
Standards Nos. 203 and 204 "would provide little 
benefit" in those vehicles. Using data from the 
agency's original analysis of the injury experience 
of passenger cars produced before and after 
Standards Nos. 203 and 204 took effect, MVMA 
said that the primary benefit of the standards is to 
reduce moderate instead of severe-to-fatal injuries. 
It pointed out that 65.6 percent of the steering 
assembly related injuries in pre-standard cars were 
minor, 22.7 percent were moderate and 11.9 per- 
cent were severe-to-fatal. In post-standard, cars 
78.8 percent of the steering assembly related 
injuries were minor, 10.2 percent were moderate 
and 11.0 were severe-to-fatal. Thus, in post- 
standard cars, many previously moderate injuries 
were only minor injuries. Using data from a 
Calspan study of light truck and van injuries, 
MVMA said that 83.5 percent of the steering 
column related injuries in those vehicles are minor, 
4.1 percent are moderate and 12.4 percent are 
severe-to-fatal. MVMA said that the Calspan data 



indicate that there is "little room" for a passenger 
car-type of injury experience change from moderate 
to minor injuries in light trucks and vans. 

However, the Calspan data cited by MVMA are 
not comparable with the NHTSA data and prob- 
ably underestimate the percentage of moderate 
and severe-to-fatal steering assembly related 
injuries in light trucks and vans. The Calspan data 
include injuries from all types of impacts (front, 
rear and side). The NHTSA data, on the other 
hand, cover only frontal crashes, the type of 
crashes which are most likely to cause severe-to- 
fatal steering assembly related injuries. Thus, the 
percentage of moderate and severe-to-fatal 
injuries found in the NHTSA data should be 
greater. In addition, an updated NHTSA analysis 
of passenger car injury experience, discussed 
below, shows that Standards Nos. 203 and 204 are 
effective in reducing both moderate and severe-to- 
fatal injuries. Further, even if the actual light 
truck and van injury distribution were the same as 
found by Calspan, Standards Nos. 203 and 204 
would be effective in reducing the number of 
severe-to-fatal injuries. 

Several manufacturers and the MVMA objected to 
the agency's use of passenger car data to estimate 
the potential effectiveness of the three standards in 
light trucks, buses and MPV's. They argued that the 
agency should instead have conducted a study com- 
paring the accident experience of light trucks, buses 
and MPV's that currently comply with the standards 
with the experience of those that do not comply. As 
explained below, NHTSA concludes that such a study 
is impractical and that the agency's original and 
updated analyses of passenger car effectiveness data 
are valid and support application of the standards to 
light trucks, buses and MPV's. 

The primary difficulty in conducting a study of 
current light trucks, buses and MPV's is that there 
is no conclusive information identifying which 
vehicles are currently in compliance with the 
standard, since no manufacturer is required to 
certify compliance. For example, International 
Harvester (IH) requested NHTSA to conduct a 
study of currently complying light trucks, buses 
and MPV's, saying that its Scout models were 
designed to comply with the performance re- 
quirements of Standards Nos. 201, 203 and 204. 
However, IH said that if the NHTSA applies the 



PART 571; S 203-PRE-5 



standards to light trucks, buses and MPV's, it will 
have to re test the Scout, which "could conceivably 
require some additional redesigning for compliance 
assurance." NHTSA belives that the analysis the 
agency conducted of pre- and post- 1968 passenger 
car injury experience, where it was known that 
passenger cars manufactured on or after January 1, 
1968, had to comply with Standards Nos. 201, 203 
and 204, provides a sound basis for estimating the 
potential effectiveness of the standards in other 
types of vehicles. 

Using information recently made available from 
the agency's National Crash Severity Study, 
NHTSA has again compared injuries sustained by 
occupants of cars manufactured before Standards 
Nos. 201, 203 and 204 went into effect with injuries 
sustained by occupants of cars manufactured after 
the standards went into effect. As with the 
agency's first analysis, cited in the November 9, 
1978, notice for this rulemaking, the new analysis 
examined injuries caused by components covered 
by Standard No. 201, such as instrument panels, 
seat backs, arm rests and sun visors. The analysis 
found that Standard No. 201 reduced severe to 
fatal occupant injuries (i.e., injuries with an 
abbreviated injury scale ranking of 3 or more) by 
approximately 38 percent. The analysis also found 
that the probability of an occupant injured in a 
crash being injured by a component covered by 
Standard No. 201 was 25.7 percent. Thus, 
multiplying the probability of injury (i.e., 25.7 
percent) by the effectiveness of the standard in 
reducing serious and fatal injuries (i.e., 38 percent) 
the analysis estimated that the overall reduction in 
severe to fatal injuries attributable to Standard 
No. 201 is 9.3 percent. 

A similar comparison was made for occupant 
injuries in cars manufactured before and after 
Standards Nos. 203 and 204 went into effect. The 
comparison examined two sets of driver injuries 
that occurred in frontal crashes. One set consisted 
of injuries that could be specifically attributed to 
contact with the steering assembly; the other set 
consisted of neck, chest and abdominal injuries sus- 
tained by drivers in frontal crashes, the types of 
steering assembly-related injuries the standards 
are designed to reduce. The comparison found that 
Standards Nos. 203 and 204 reduced severe to 
fatal injuries by an average of 20.9 percent. The 



probability of an injured driver receiving an injury 
attributable to the steering assembly was an 
average of 19.4 percent. The analysis estimated 
that Standards Nos. 203 and 204 produced an 
overall average reduction of 3.7 percent in severe 
to fatal driver injuries. 

Loading Requirements 

At present, Standared No. 204 does not specify 
the loading requirements for vehicles in the 30 mph 
fixed barrier crash test required by the standard. 
In conducting Standard No. 204 compliance tests 
for passenger cars, the agency has loaded 
passenger cars to their unloaded vehicle weight 
(i.e., the weight of the vehicle with all the fluid, 
such as gas, oil and water, necessary for its opera- 
tion but without any occupants or cargo). This is 
the least severe loading condition used in the 
Federal Motor Vehicle Safety Standards that 
involve crash testing. This notice makes a technical 
amendment to Standard No. 204 to incorporate the 
agency long-standing loading practices. Those 
practices were publicly announced in the 
compliance test procedures publicly released by the 
agency when Standard No. 204 first went into 
effect in 1968. Passenger car certification informa- 
tion provided by manufacturers to NHTSA shows 
that they have consistently used unloaded vehicle 
weight as the loading condition in their testing. In 
some instances, manufacturers have voluntarily 
used more severe loading conditions in their 
certification testing. 

Commerical Vehicles 

Several final stage manufacturers and United 
Parcel Service requested the agency to exempt 
vehicles used in commercial applications from the 
standards. A similar exemption has previously 
been sought by the Truck Body and Equipment 
Association (TBEA) for Standard No. 212-76, 
Windshield Mounting, and Standard 219-75, 
Windshield Zone Intrusion. As with the TBEA 
request, NHTSA concludes that such an exemption 
should not be adopted since it is not in the interest 
of safety and is based on vehicle use instead of 
vehicle type. Such an exemption would mean that 
standards would be applied on the basis of the 
commercial or private use of the vehicle and not 
upon the safety needs of a particular vehicle type. 
Since the safety needs of similar vehicles usually 
are similar, it would be inappropriate to treat one 
set of vehicles differently merely because they are 
used commercially. 



PART 571; S 203-PRE-6 



The National Traffic and Motor Vehicle Safety 
Act contemplates the application of the standards 
based on vehicle type instead of vehicle use. Basing 
a standard on vehicle use would present this agency 
with difficult enforcement problems. It would also 
place a manufacturer in the difficult position of 
having to assess in advance the potential future 
use of the vehicle it produces. In addition, basing 
standards application on vehicle use does not 
recognize that a vehicle may have two or more uses 
during its lifetime. 

For all these reasons, the agency concludes that 
applying standards based on vehicle use would not 
be appropriate. 

Walk-In Vans 

GM, MVMA and several final-stage manufac- 
turers requested the agency to exempt walk-in 
vans (i.e., the "step-van" city delivery type of vehicle 
that permits a person to enter the vehicle without 
stooping) from Standards Nos. 201, 203 and 204. 
In the case of Standard No. 201, they argued that 
this type of vehicle frequently has none of the com- 
ponents covered by the standard, such as arm 
rests, sun visors and instrument panels to the right 
of the steering assembly. However, those vehicles 
do have an instrument panel in front of the driver 
and some walk-in vans do have a front passenger 
seat and an instrument panel in front of that seat 
which may be struck by an occupant during a 
crash. Applying Standard No. 201 to those vehicles 
will require the instrument panel to be padded to 
cushion occupant impacts. Based on the proven 
effectiveness of Standard No. 201 in passenger 
cars, the agency is extending the performance 
requirements of the standard to include walk-in 
vans and MPV's. 

The manufacturers argued that walk-in vans 
should be exempt from Standards Nos. 203 and 
204 also. They said that the driver steering 
assembly configuration found in walk-in vans 
makes it improbable that compliance with the 
standard will reduce drivers' injuries. They noted 
that the steering column is mounted in those 
vehicles at an angle of 55-60 degrees, compared to 
the mounting angle of 30 degrees found in conven- 
tional trucks, and the columns in walk-in vans 
move upward rather than rearward in a crash. The 
manufacturers also argued that these vehicles are 
generally used in urban areas, where there is more 



slow speed traffic than in rural areas. They pointed 
out that because of these factors, the agency has 
previously exempted walk-in vans from Standards 
Nos. 212-76, Windshield Retention, and 219-75, 
Windshields Zone Intrusion. The agency agrees 
that current energy absorbing steering column 
designs probably would provide little, if any, pro- 
tection in walk-in vans because of their uniques 
driver/ steering column configuration, and thus is 
exempting walk-in vans for the present. 

Belts in Forward Control Vehicles 

Although they did not object to requiring lap- 
shoulder belts in forward control vehicles as pro- 
posed in the agency's November 9, 1978 notice, 
several manufacturers and the MVMA objected to 
what they interpreted as a conflict between the 
agency's proposal and the current requirements of 
Standard No. 208, Occupant Crash Protection. 
They argued that the agency's proposal not only 
would require lap and shoulder belts in forward 
control vehicles, but would also require such belts 
in open-body vehicles, convertibles and walk-in 
vans, which currently only have to have lap belts. 
The agency's proposal was directed only toward 
forward control vehicles and was meant to 
supersede the current requirements for those 
vehicles set in Standard No. 208. For organiza- 
tional simplicity, the agency is making a technical 
amendment to Standard No. 208 so that all belt 
requirements are centralized in that standard. The 
amendment only adopts the proposed change to 
the forward control vehicle belt requirements. It 
does not change the current belt requirements for 
open-body vehicles, convertibles and walk-in vans. 

MVMA requested the agency to require lap and 
shoulder belts in forward control vehicles for only 
one model year. MVMA did not provide any 
justification for that request. NHTSA believes that 
the important protection of lap and shoulder belts 
should be available to all forward control vehicles 
manufactured on or after September 1, 1981, and 
declines to adopt the MVMA request. 

Upgrading of Standard 

In their comments, the Center for Auto Safety 
and the Insurance Institute for Highway Safety 
renewed their requests that the agency set new 
performance requirements for Standard No. 203 to 
provide additional protection in angular impacts. 
The agency has conducted some preliminary 
testing to determine what additional requirements 



PART 571; S 203-PRE-7 



may be appropriate to increase protection in 
angular impacts. In addition, the agency's 
National Center for Statistics and Analysis has 
recently begun a special study to collect accident 
data on 1973 and later model vehicles to gather 
additional information on the effectiveness of 
energy absorbing steering assemblies in angular 
and other crashes. Based on that data, NHTSA 
will make a determination of what further changes 
are needed in the standard. 

The American Automobile Association asked the 
agency to delay application of Standard No. 203 
until upgraded performance requirements are 
developed. However, because the agency does not 
want to delay providing the occupants of light 
trucks, buses and MPV's with the safety benefits 
of Standard No. 203, the agency is extending the 
standards to those vehicles while it continues to 
consider the feasibility of additional performance 
requirements. 

NHTSA is also considering possible additional 
requirements for Standard No. 201. The agency 
has scheduled a meeting for December 11, 1979, so 
that the public can present its views and ideas on 
ways of improving protection for children involved 
in vehicle collisions. In the September 4, 1979, 
notice announcing the meeting, the agency 
specifically asked for comments on possible 
improvements to the interior padding of vehicles to 
provide additional protection for children (44 FR 
51623). 

Heavy Trucks 

In the November 9, 1978 notice, NHTSA 
announced that it was evaluating whether to 
extend the applicability of Standards Nos. 201, 203 
and 204 to heavy trucks (i.e., trucks with a GVWR 
of more than 10,000 pounds) and solicited 
comments on appropriate performance 
requirements for those vehicles. In their com- 
ments, the Motor Vehicle Manufacturers Associa- 
tion, Freightliner and International Harvester all 
opposed an extension of the standards to trucks 
with a GVWR greater than 10,000 pounds, arguing 
that there is no data showing a safety need for 
applying the standards to those vehicles. They also 
argued that because of the size and weight of heavy 
trucks, occupants in these vehicles do not 
experience the same energy transfers in a crash 
than passenger car occupants experience and thus 
theoretically should incur fewer or less severe 



injuries. At the agency's recent meeting on heavy 
truck safety, several participants provided in- 
formation on the need for greater crash protection 
for drivers of heavy trucks. NHTSA is currently 
analyzing that information to determine what 
additional heavy truck regulatory action may be 
needed. 
Miscellaneous Comments 

MVMA pointed out that Standard No. 201 
currently requires two sun visors in a vehicle and 
requested that a second visor not be required if 
there is no front passenger seat. NHTSA agrees 
that such a change is appropriate and has made the 
necessary amendment to the standard. 

Jeep Corp. objected to the application of 
Standard No. 201 to open-body MPV's, arguing 
that for Jeep to locate padding in the expected 
head impact area it would have to raise its padding 
or lower its seat, both of which it claimed would 
interfere with the driver's forward visibility. 
Jeep's comment appears to reflect a misunder- 
standing of Standard No. 201. The performance 
requirements of the standard only apply to areas of 
the instrument panel that are within the head 
impact area of each designated seating position. 
(The head impact area is the portion of the 
vehicle's interior that can be contacted by a head- 
form representing an occupant's head.) "Thus, if a 
portion of Jeep's vehicle instrument panel is not 
within the head impact area, it does not have to 
comply. For portions of the panel that are within 
the head impact area. Jeep can make structural 
changes to the instrument panel to meet Standard 
No. 201 without adding additional padding. 
Therefore, Jeep's requested exemption for all 
open-body vehicles is denied. 

One final stage manufacturer, Boyertown Auto 
Body Works, asked NHTSA whether its driver 
side instrument panel was within the exeptions to 
Standard No. 201 and, if not, sought to have its in- 
strument panel construed to be a console assembly, 
which is exempt from the standard. Such an inter- 
pretation is not acceptable since Boyertown clearly 
labels the area in question as an instrument panel 
in its engineering drawings. However, according 
to the engineering drawing provided by Boyer- 
town, the limited section on the instrument panel 
of concern to Boyertown is within the area 
exempted by S3. 1.1(d) of the standard. That 
section provides that the area of the interior 
immediately forward of the steering column is 
exempt from the standard. 



PART 571; S 203-PRE-8 



Costs and Leadtime 

NHTSA has considered the economic and other 
impacts of this final rule and determined that they 
are not significant within the meaning of 
Executive Order 12044 and the Department of 
Transportation's poHcies and procedures for 
implementing that order. The agency's assessment 
of the benefits and economic consequences of this 
proposal are contained in a regulatory evaluation 
which has been places in the public docket. As 
explained previously, copies of the regulatory 
evaluation can be obtained by writing NHTSA's 
docket section at the address given in the begin- 
ning of this final rule. 

As previously detailed in this notice, the agency 
has examined the effectiveness of Standards Nos. 
201, 203 and 204 in passenger cars and- concluded 
that those standards have brought about a substan- 
tial reduction in overall injuries occurring to the 
passengers in those vehicles. Because they share 
the same driving environment as occupants in 
passenger cars, occupants in light trucks, buses 
and MPV's face a similar risk of injury posed by 
hazardous instrument panels and rigid steering 
columns. Based on its evaluation of the effec- 
tiveness of Standards Nos. 201, 203 and 204 in 
passenger cars, the agency has concluded that 
applying those standards to light trucks, buses and 
MPV's can result in a reduction of 120 to 240 
fatalities and 4,400 to 8,900 serious injuries per 
year when all those vehicles comply with the 
standards. 

The agency's cost estimate for meeting 
Standards Nos. 201, 203 and 204 in light trucks, 
buses and MPV's take into account that many 
manufacturers have equipped some of their 
vehicles with components designed to meet the 
performance requirements of the standards. Those 
components may need little or no redesigning to 
fully comply with the standards. For example, 
American Motors, Chrysler, Ford, General 
Motors, International Harvester and Volkswagen 
commented that some, if not all, of their vehicles 
currently have components designed to comply 
with the standards or they will install such com- 
ponents in some of their vehicles by the 1981 model 
year. 

Only two manufacturers, Nissan and Ford, pro- 
vided any information about the costs associated 
with complying with the standards. Nissan said 



that the cost associated with complying with all 
three standards was $30. Ford estimated the cost 
for compliance with Standard No. 201 as $10 per 
vehicle; based on preliminary design assumptions. 
Ford put the cost of complying with Standards 
Nos. 203 and 204 in its van-type trucks, buses and 
MPV's at $120 per vehicle. 

To provide the agency with additional informa- 
tion about the estimated costs of complying with 
the three standards, NHTSA contracted with the 
John Z. DeLorean Corp. to evaluate current 
vehicles and determine what changes would be 
needed to bring the vehicles into compliance. Bases 
on its review of current foreign and domestic light 
trucks, buses and MPV's, DeLorean concluded 
that the total cost of compliance with the three 
standards would add a sales weighted average of 
$16 to the retail price of those vehicles. The 
DeLorean study reported that the vehicles requir- 
ing the most changes to meet Standards Nos. 201, 
203 and 204 were van-type trucks, buses and 
MPV's made by GM and Ford. DeLorean 
estimated that GM and Ford van-types vehicles 
would require a $27 increase in consumer price to 
comply with Standards Nos. 203 and 204 and a 
price increase ranging between $6 and $15 to 
comply with Standard No. 201. The agency 
believes that the substantial difference between 
DeLorean's and Ford's estimate of the cost of 
compliance with Standards Nos. 203 and 204 may 
be due to Ford's overestimate of the anticipated 
changes needed in the vehicles based on its 
preliminary design asssumptions. 

The agency's November 1978 notice proposed an 
effective date of September 1, 1980, for Standard 
No. 201 for all vehicles and for Standards Nos. 203 
and 204 for nonforward control vehicles. An effec- 
tive date of September 1, 1981, was proposed for 
Standards Nos. 203 and 204 for forward control 
vehicles to allow manufacturers additional time to 
make the necessary changes in those vehicles. In 
their comments on Standard 201, Chrysler and 
Ford said they could meet the standard in all their 
vehicles by the proposed effective date. Nissan, 
Toyo Kogyo and International Harvester (IH) 
requested from 18 to 24 months leadtime. General 
Motors requested 2V2 " years' leadtime and 
American Motors requested 3 years. As a part of 
its NHTSA-funded study of the costs of complying 
with the standard, the DeLorean Corp. also 
examined the leadtime necessary to comply with 



PART 571; S 203-PRE-9 



the standard. For Standard No. 201, the DeLorean 
study concluded that only one year was needed for 
all vehicles except van-type trucks, buses and 
MPV's manufactured by Chrysler and GM, which 
needed two years. 

For Standards Nos. 203 and 204, Chrysler said 
that all its vehicles, except its incomplete forward 
control van-type vehicles, can comply by 
September 1, 1980. Chrysler did not provide an 
estimate of leadtime needed for its incomplete 
forward control vans. Nissan, Toyo Kogyo and IH 
requested from 18 to 24 months leadtime. Ford 
said its 1980 model year F-series trucks and 
Bronco models would comply with the standards 
and the Courier truck chassis cab imported by Ford 
would comply by September 1, 1981. Ford 
requested until September 1, 1982, for its van-type 
trucks, buses and MPV's. General Motors 
requested 2V2 years for all its vehicles and 
American Motors requested three years. 

The DeLorean study concluded that 18-24 
months of leadtime was needed for all models, 
except those made by Ford, which would require 
three years. DeLorean made its estimate of lead- 
time for Ford based on an assumption that Ford 



would need extra steering assembly tooling 
facilities. However, since Ford plans to introduce 
complying components on its 1980 model F series 
trucks and Bronco models. Ford has apparently 
developed the needed tooling capacity. 

Based on its analysis of the DeLorean study and 
of the industry's comments, NHTSA concludes 
that setting an effective date of September 1, 
1981, will allow sufficient time for all manufac- 
turers to comply with the standards. This action 
provides an additional year for all light trucks, 
buses and MPV's to meet Standard No. 201 and for 
nonforward control vehicles to meet Standards 
Nos. 203 and 204. 

The principal authors of this notice are William 
Smith, Office of Vehicle Safety Standards, and 
Stephen Oesch, Office of Chief Counsel. 

Issued on November 12, 1979. 



Joan Claybrook 
Administrator 

44 F.R. 68470 
November 29, 1979 



PART 571; S 203-PRE-lO 



i 



MOTOR VEHICLE SAFETY STANDARD NO. 203 
Impact Protection for the Driver from the Steering Control System— Passenger Cars 

(Docket Nos. 2 and 3; Notice 1) 



51. Purpose and scope. This standard 
specifies requirements for steering control 
systems that will minimize chest, neck, and facial 
injuries to the driver as a result of impact. 

52. Application. This standard applies to 
passenger cars and to multipurpose passenger 
vehicles, trucks and buses with a GVWR of 10,000 
pounds or less. However, it does not apply to 
vehicles that conform to the frontal barrier crash 
requirements (S5.1) of Standard No. 208 (49 CFR 
571.208) by means of other than seat belt 
assemblies. It also does not apply to walk-in vans. 

53. Definitions. "Steering control system" 
means the basic steering mechanism and its 
associated trim hardware, including any portion of 
a steering column assembly that provides energy 
absorption upon impact. 

54. Requirements. Each passenger car and 
each multipurpose passenger vehicle, truck and 
bus with a GVWR of 10,000 pounds or less 
manufactured on or after September 1, 1981, shall 
meet the requirements of S5.1 and 85. 2. 

S4.1 Except as provided in S4.2. when the 
steering control system is impacted by a body block 
in accordance with Society of Automotive 
Engineers Recommended Practice J944, "Steer- 
ing Wheel Assembly Laboratory Test Procedure," 
December 1965 or an approved equivalent, at a 
relative velocity of 15 miles per hour, the impact 
force developed on the chest of the body block 
transmitted to the steering control system shall 
not exceed 2,500 pounds. 



54.2 A Type 2 seat belt assembly that conforms 
to Motor Vehicle Safety Standard No. 209 shall be 
installed for the driver of any vehicle with forward 
control configuration that does not meet the 
requirements of S4.1. 

54.3 The steering control system shall be so 
constructed that no components or attachments, 
including horn actuating mechanisms and trim 
hardware, can catch the driver's clothing or 
jewelry during normal driving maneuvers. 

S5. Impact protection requirements. 

55.1 When the steering control system is 
impacted by a body block in accordance with Society 
of Automotive Engineers Recommended Practice 
J944, "Steering Wheel Assembly Laboratory Test 
Procedure," December 1965, or an approved 
equivalent, at a relative velocity of 15 miles per hour, 
the impact force developed on the chest of the body 
block transmitted to the steering control system shall 
not exceed 2,500 pounds. 

55.2 The steering control system shall be so 
constructed that no components or attachments, 
including horn actuating mechanisms and trim 
hardware, can catch the driver's clothing or 
jewelry during normal driving maneuvers. 

Interpretation 

The term "Jewelry" in paragraph S4.3 refers to 
watches, rings, and bracelets without loosely 
attached or dangling members. 

32 F.R. 2414 
February 3, 1967 



PART 571; S 203-1 



PREAMBLE TO AMENDMENTS TO MOTOR VEHICLE SAFETY STANDARDS 

NO. 204 

Steering Control Rearward Displacement 
(Docket No. 78-116; Notice 2) 



ACTION: Final rule. 

SUMMARY: This notice amends Federal Motor 
Vehicle Safety Standards Nos. 201, 203 and 204 to 
extend their applicability to light trucks, buses and 
multipurpose passenger vehicles (MPV's). The 
notice is issued in response to the rising death and 
injury toll involving these vehicles and to petitions 
by the Center for Auto Safety and the Insurance 
Institute for Highway Safety requesting that these 
standards be extended to those vehicles. Applying 
these standards to light trucks, buses and MPV's 
will reduce occupant deaths and injuries in those 
vehicles by requiring the use of energy absorbing 
material on such interior components as the instru- 
ment panel and seat backs (Standard No. 201), by 
limiting the amount of force that can be exerted on 
the driver's chest by the steering wheel in frontal 
crashes (Standard No. 203), and by limiting the 
rearward movement of the steering assembly in 
frontal crashes (Standard No. 204). 

EFFECTIVE DATE: The effective date for the 
extension of applicability of Standards Nos. 201, 
203 and 204 is September 1, 1981. 

ADDRESS: Petitions for reconsideration should 
refer to the docket number and be submitted to: 
Docket Section, Room 5108, National Highway 
Traffic Safety Administration, 400 Seventh Street, 
S.W., Washington, D.C. 20590. 

FOR FURTHER INFORMATION CONTACT: 

Mr. William Smith, Office of Vehicle Safety 
Standards, National Highway Traffic Safety 
Administration, 400 Seventh Street, S.W., 
Washington, D.C. 20590 (202-426-2242) 



SUPPLEMENTARY INFORMATION: This notice 
amends Standard No. 201, Occupant Protection in 
Interior Impact, and Standard No. 203, Impact 
Protection for the Driver From the Steering 
Control System, to extend the applicability of those 
standards to trucks, buses and multipurpose 
passenger vehicles (MPV's) with a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less. 
This notice also amends Standard No. 204, 
Steering Control Rearward Displacement, to 
extend its applicability to trucks, buses and MPV's 
with an unloaded vehicle weight of 4,000 pounds or 
less, instead of all trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less, as originally 
proposed in the agency's November 9, 1978, notice 
of proposed rulemaking (43 FR 52264). As explained 
below, the agency is initially limiting the extended 
applicability of Standard No. 204 while it studies 
methods for dealing with final-stage manufacturer 
certification difficulties. Similar possible problems 
with Standard No. 212-76, Windshield Mounting, 
and Standard No. 219-75, Windshield Zone Intru- 
sion, led the agency to propose changes in the 
testing procedures for those standards (44 FR 
45426). 

For the purposes of Standard No. 204, the agency 
has determined that these problems would not be 
encountered in applying the standard to vehicles 
with an unloaded vehicle weight of 4,000 pounds or 
less and testing them at their unloaded vehicle 
weight. Approximately 75 percent of the current 
sales of light trucks, buses and MPV's with a 
GVWR of 10,000 pounds or less have an unloaded 
vehicle weight of 4,000 pounds or less. 

This final rule was preceded by a notice propos- 
ing the extension of the applicability of Standards 



PART 571; S 204-PRE-l 



Nos. 201, 203 and 204 in November 1978 (43 FR 
52264). Private citizens, safety organizations, 
manufacturers and a manufacturer trade associa- 
tion submitted comments on the proposal. NHTSA 
has considered all of those comments and the most 
significant ones are discussed below. 

Safety Need 
Citing the need to reduce the number of deaths 
and injuries in light trucks, buses and MPV's, the 
American Automobile Association, the Center for 
Auto Safety, the Insurance Institute for Highway 
Safety and State Farm Insurance Companies 
supported application of the standards to those 
vehicles. 

Although it did not object to extending the 
applicability of Standard Nos. 201, 203 and 204 to 
light trucks, buses and MPV's, General Motors 
argued that manufacturers should be given a 
longer lead time to comply with the standards 
because of the lack of urgent safety need. GM said 
that allowing a longer leadtime was desirable to 
ensure compliance, "without costly accelerated 
[design] programs." Using data from the agency's 
"Explanation of Rulemaking," GM said that light 
trucks, buses and MPV's have a fatality rate of 
22.4 fatalities per billion miles, compared with a 
rate of 25.3 fatalities per billion miles for 
passenger cars. The data GM used covers fatalities 
during 1977 in all model year vehicles. A new 
analysis done by NHTSA of 1977 fatalities, 
reported by the agency's Fatal Accident Reporting 
System, shows that although older model year 
light trucks, buses and MPV's may have had a 
lower fatality rate than passenger cars, beginning 
with the 1973 model year, the combined fatality 
rate for light trucks, buses and MPV's began 
surpassing that of passenger cars. The analysis 
shows that recent model year passenger cars have 
a considerably lower fatality rate than light trucks, 
buses and MPV's. (A copy of that analysis has been 
placed in the docket.) 

In addition to being higher than the combined 
fatality rate for all sizes of passenger cars, the 
combined fatality rate of light trucks, buses and 
MPV's is far higher than the rate for full-size 
passenger cars. Full-size cars are typically the 
safest of cars and many of them are comparable in 
size and weight to light trucks, buses and MPV's. 
In theory, occupants of larger and heavier vehicles, 
such as trucks, buses and MPV's, should experience 



less harmful crash forces, and thus presumably incur 
fewer or less severe injuries, than occupants of 
smaller lighter vehicles. Volkswagen has previously 
objected to a comparison of full-size passenger 
fatality rates with those for vans, arrguing that 
vans are comparable in weight to intermediate, not 
full-size passenger cars. Although the unloaded 
weight of vans and intermediate-size passenger 
cars may be comparable, vans have a higher gross 
vehicle weight rating which means that those 
vehicles can, in actual use, be loaded with substan- 
tially more weight than intermediate and even full- 
size passenger cars. 

Volkswagen also questioned the safety need for 
the proposed reulmaking because of the voluntary 
compliance by VW and some other companies with 
the standards. Although the voluntary effort by 
some companies is commendable, most manufac- 
turers do not comply with all of the standards in all 
of their vehicles. Some of the manufacturers who 
have taken steps to comply with the standard 
presumably were in part motivvated by prior 
NHTSA rulemaking notices proposing to apply 
Standards Nos. 201,203 and 204 to light trucks, 
buses and MPV's (35 FR 14936, 14936 and 16805). 
In the absence of a regulation, there is no 
assurance that non-complying manufacturers will 
produce complying vehicles and that manfacturers 
producing currently complying vehicles will 
continue to comply. Manufacturers who currently 
comply should experience only minor economic 
impacts, such as conducting certification tests as a 
result of compelling other manufacturers to 
comply. 

Effectiveness 

The Motor Vehicle Manufacturers Association 
(MVMA) questioned the potential effectiveness of 
Standards Nos. 201, 203 and 204. MVMA argue 
that a study done bySherman and Huelke of light 
truck and van accidents found that the standards 
would have little effect in those vehicles. However, 
a NHTSA analysis of the crashes reviewed by 
Sherman and Huelke found that a number of the 
crashes clearly edmonstrated the benefits of equip- 
ping light trucks and vans with energy absorbing 
instrument panels and steering columns and devices 
to limit the rearward displacement of the steering 
column. For example, Sherman and Huelke studied 
a 15-20 mph head-on crash of a 1976 Chevrolet 



PART 571; S 204-PRE-2 



pickup truck intx) a tree. The Chevrolet was equipped 
with a padded instrument panel, and energy- 
absorbing steering column and a device to limit the 
rearward displacement of the steering column. They 
reported, "the results of this case show that both of 
the major energy absorbing components appeared to 
have completely activated, both by the vehicle crash 
and driver impact, providing maximum benefit to the 
driver. Had this vehicle been one of the other vehicle 
cases discussed in this section, we feel that the in- 
juries sustained by the driver would have been much 
more severe." 

NHTSA believes further that the Sherman and 
Huelke study provides information indicating that 
there is a need for even more improvements in 
light trucks and vans, such as providing energy- 
absorbing padding for the lower instrument panel. 
The agency is studying the question of making 
appropriate changes in the performance 
requirements of the standards to require more pro- 
tection. However, NHTSA considers it important 
not to delay extending the current benefits of 
Standards Nos. 201, 203 and 204 while it reviews 
possible changes to the standards. 

MVMA also argued that a comparison of the 
injury experience of passenger car steering 
assemblies with the experience of steering 
assemblies in light trucks and vans shows that 
Standards Nos. 203 and 204 "would provide little 
benefit" in those vehicles. Using data from the 
agency's original analysis of the injury experience 
of passenger cars produced before and after 
Standards Nos. 203 and 204 took effect, MVMA 
said that the primary benefit of the standards is to 
reduce moderate instead of severe-to-fatal injuries. 
It pointed out that 65.6 percent of the steering 
assembly related injuries in pre-standard cars were 
minor, 22.7 percent were moderate and 11.9 per- 
cent were severe-to-fatal. In post-standard, cars 
78.8 percent of the steering assembly related 
injuries were minor, 10.2 percent were moderate 
and 11.0 were severe-to-fatal. Thus, in post- 
standard cars, many previously moderate injuries 
were only minor injuries. Using data from a 
Calspan study of light truck and van injuries, 
MVMA said that 83.5 percent of the steering 
column related injuries in those vehicles are minor, 
4.1 percent are moderate and 12.4 percent are 
severe-to-fatal. MVMA said that the Calspan data 



indicate that there is "little room" for a passenger 
car-type of injury experience change from moderate* 
to minor injuries in light trucks and vans. 

However, the Calspan data cited by MVMA are 
not comparable with the NHTSA data and prob- 
ably underestimate the percentage of moderate 
and severe-to-fatal steering assembly related 
injuries in light trucks and vans. The Calspan data 
include injuries from all types of impacts (front, 
rear and side). The NHTSA data, on the other 
hand, cover only frontal crashes, the type of 
crashes which are most likely to cause severe-to- 
fatal steering assembly related injuries. Thus, the 
percentage of moderate and severe-to-fatal 
injuries found in the NHTSA data should be 
greater. In addition, an updated NHTSA analysis 
of passenger car injury experience, discussed 
below, shows that Standards Nos. 203 and 204 are 
effective in reducing both moderate and severe-to- 
fatal injuries. Further, even if the actual light 
truck and van injury distribution were the same as 
found by Calspan, Standards Nos. 203 and 204 
would be effective in reducing the number of 
severe-to-fatal injuries. 

Several manufacturers and the MVMA objected to 
the agency's use of passenger car data to estimate 
the potential effectiveness of the three standards in 
light trucks, buses and MPV's. They argued that the 
agency should instead have conducted a study com- 
paring the accident experience of light trucks, buses 
and MPV's that currently comply with the standards 
with the experience of those that do not comply. As 
explained below, NHTSA concludes that such a study 
is impractical and that the agency's original and 
updated analyses of passenger car effectiveness data 
are valid and support application of the standards to 
light trucks, buses and MPV's. 

The primary difficulty in conducting a study of 
current light trucks, buses and MPV's is that there 
is no conclusive information identifying which 
vehicles are currently in compliance with the 
standard, since no manufacturer is required to 
certify compliance. For example. International 
Harvester (IH) requested NHTSA to conduct a 
study of currently complying light trucks, buses 
and MPV's, saying that its Scout models were 
designed to comply with the performance re- 
quirements of Standards Nos. 201, 203 and 204. 
However, IH said that if the NHTSA applies the 



PART 571; S 204-PRE-3 



standards to light trucks, buses and MPV's, it will 
have to retest the Scout, which "could conceivably 
require some additional redesigning for compliance 
assurance." NHTSA belives that the analysis the 
agency conducted of pre- and post-1968 passenger 
car injury experience, where it was known that 
passenger cars manufactured on or after January 1, 
1968, had to comply with Standards Nos. 201, 203 
and 204, provides a sound basis for estimating the 
potential effectiveness of the standards in other 
types of vehicles. 

Using information recently made available from 
the agency's National Crash Severity Study, 
NHTSA has again compared injuries sustained by 
occupants of cars manufactured before Standards 
Nos. 201, 203 and 204 went into effect with injuries 
sustained by occupants of cars manufactured after 
the standards went into effect. As with the 
agency's first analysis, cited in the November 9, 
1978, notice for this rulemaking, the new analysis 
examined injuries caused by components covered 
by Standard No. 201, such as instrument panels, 
seat backs, arm rests and sun visors. The analysis 
found that Standard No. 201 reduced severe to 
fatal occupant injuries (i.e., injuries with an 
abbreviated injury scale ranking of 3 or more) by 
approximately 38 percent. The analysis also found 
that the probability of an occupant injured in a 
crash being injured by a component covered by 
Standard No. 201 was 25.7 percent. Thus, 
multiplying the probability of injury (i.e., 25.7 
percent) by the effectiveness of the standard in 
reducing serious and fatal injuries (i.e., 38 percent) 
the analysis estimated that the overall reduction in 
severe to fatal injuries attributable to Standard 
No. 201 is 9.3 percent. 

A similar comparison was made for occupant 
injuries in cars manufactured before and after 
Standards Nos. 203 and 204 went into effect. The 
comparison examined two sets of driver injuries 
that occurred in frontal crashes. One set consisted 
of injuries that could be specifically attributed to 
contact with the steering assembly; the other set 
consisted of neck, chest and abdominal injuries sus- 
tained by drivers in frontal crashes, the types of 
steering assembly-related injuries the standards 
are designed to reduce. The comparison found that 
Standards Nos. 203 and 204 reduced severe to 
fatal injuries by an average of 20.9 percent. The 



probability of an injured driver receiving an injury 
attributable to the steering assembly was an 
average of 19.4 percent. The analysis estimated 
that Standards Nos. 203 and 204 produced an 
overall average reduction of 3.7 percent in severe 
to fatal driver injuries. 

Loading Requirements 

At present, Standared No. 204 does not specify 
the loading requirements for vehicles in the 30 mph 
fixed barrier crash test required by the standard. 
In conducting Standard No. 204 compliance tests 
for passenger cars, the agency has loaded 
passenger cars to their unloaded vehicle weight 
(i.e., the weight of the vehicle with all the fluid, 
such as gas, oil and water, necessary for its opera- 
tion but without any occupants or cargo). This is 
the least severe loading condition used in the 
Federal Motor Vehicle Safety Standards that 
involve crash testing. This notice makes a technical 
amendment to Standard No. 204 to incorporate the 
agency long-standing loading practices. Those 
practices were publicly announced in the 
compliance test procedures publicly released by the 
agency when Standard No. 204 first went into 
effect in 1968. Passenger car certification informa- 
tion provided by manufacturers to NHTSA shows 
that they have consistently used unloaded vehicle 
weight as the loading condition in their testing. In 
some instances, manufacturers have voluntarily 
used more severe loading conditions in their 
certification testing. 

Commerical Vehicles 

Several final stage manufacturers and United 
Parcel Service requested the agency to exempt 
vehicles used in commercial applications from the 
standards. A similar exemption has pre'/iously 
been sought by the Truck Body and Equipment 
Association (TBEA) for Standard No. 212-76, 
Windshield Mounting, and Standard 219-75, 
Windshield Zone Intrusion. As with the TBEA 
request, NHTSA concludes that such an exemption 
should not be adopted since it is not in the interest 
of safety and is based on vehicle use instead of 
vehicle type. Such an exemption would mean that 
standards would be applied on the basis of the 
commercial or private use of the vehicle and not 
upon the safety needs of a particular vehicle type. 
Since the safety needs of similar vehicles usually 
are similar, it would be inappropriate to treat one 
set of vehicles differently merely because they are 
used commercially. 



PART 571; S 204-PRE-4 



The National Traffic and Motor Vehicle Safety 
Act contemplates the application of the standards 
based on vehicle type instead of vehicle use. Basing 
a standard on vehicle use would present this agency 
with difficult enforcement problems. It would also 
place a manufacturer in the difficult position of 
having to assess in advance the potential future 
use of the vehicle it produces. In addition, basing 
standards application on vehicle use does not 
recognize that a vehicle may have two or more uses 
during its lifetime. 

For all these reasons, the agency concludes that 
applying standards based on vehicle use would not 
be appropriate. 

Walk-In Vans 

GM, MVMA and several final-stage manufac- 
turers requested the agency to exempt walk-in 
vans (i.e., the "step-van" city delivery type of vehicle 
that permits a person to enter the vehicle without 
stooping) from Standards Nos. 201, 203 and 204. 
In the case of Standard No. 201, they argued that 
this type of vehicle frequently has none of the com- 
ponents covered by the standard, such as arm 
rests, sun visors and instrument panels to the right 
of the steering assembly. However, those vehicles 
do have an instrument panel in front of the driver 
and some walk-in vans do have a front passenger 
seat and an instrument panel in front of that seat 
which may be struck by an occupant during a 
crash. Applying Standard No. 201 to those vehicles 
will require the instrument panel to be padded to 
cushion occupant impacts. Based on the proven 
effectiveness of Standard No. 201 in passenger 
cars, the agency is extending the performance 
requirements of the standard to include walk-in 
vans and MPV's. 

The manufacturers argued that walk-in vans 
should be exempt from Standards Nos. 203 and 
204 also. They said that the driver steering 
assembly configuration found in walk-in vans 
makes it improbable that compliance with the 
standard will reduce drivers' injuries. They noted 
that the steering column is mounted in those 
vehicles at an angle of 55-60 degrees, compared to 
the mounting angle of 30 degrees found in conven- 
tional trucks, and the columns in walk-in vans 
move upward rather than rearward in a crash. The 
manufacturers also argued that these vehicles are 
generally used in urban areas, where there is more 



slow speed traffic than in rural areas. They pointed 
out that because of these factors, the agency has 
previously exempted walk-in vans from Standards 
Nos. 212-76, Windshield Retention, and 219-75, 
Windshields Zone Intrusion. The agency agrees 
that current energy absorbing steering column 
designs probably would provide little, if any, pro- 
tection in walk-in vans because of their uniques 
driver/ steering column configuration, and thus is 
exempting walk-in vans for the present. 

Belts in Forward Control Vehicles 

Although they did not object to requiring lap- 
shoulder belts in forward control vehicles as pro- 
posed in the agency's November 9, 1978 notice, 
several manufacturers and the MVMA objected to 
what they interpreted as a conflict between the 
agency's proposal and the current requirements of 
Standard No. 208, Occupant Crash Protection. 
They argued that the agency's proposal not only 
would require lap and shoulder belts in forward 
control vehicles, but would also require such belts 
in open-body vehicles, convertibles and walk-in 
vans, which currently only have to have lap belts. 
The agency's proposal was directed only toward 
forward control vehicles and was meant to 
supersede the current requirements for those 
vehicles set in Standard No. 208. For organiza- 
tional simplicity, the agency is making a technical 
amendment to Standard No. 208 so that all belt 
requirements are centralized in that standard. The 
amendment only adopts the proposed change to 
the forward control vehicle belt requirements. It 
does not change the current belt requirements for 
open-body vehicles, convertibles and walk-in vans. 

MVMA requested the agency to require lap and 
shoulder belts in forward control vehicles for only 
one model year. MVMA did not provide any 
justification for that request. NHTSA believes that 
the important protection of lap and shoulder belts 
should be available to all forward control vehicles 
manufactured on or after September 1, 1981, and 
declines to adopt the MVMA request. 

Upgrading of Standard 

In their comments, the Center for Auto Safety 
and the Insurance Institute for Highway Safety 
renewed their requests that the agency set new 
performance requirements for Standard No. 203 to 
provide additional protection in angular impacts. 
The agency has conducted some preliminary 
testing to determine what additional requirements 



PART 571; S 204-PRE-5 



may be appropriate to increase protection in 
an^lar impacts. In addition, the agency's 
National Center for Statistics and Analysis has 
recently begun a special study to collect accident 
data on 1973 and later model vehicles to gather 
additional information on the effectiveness of 
energy absorbing steering assemblies in angular 
and other crashes. Based on that data, NHTSA 
will make a determination of what further changes 
are needed in the standard. 

The American Automobile Association asked the 
agency to delay application of Standard No. 203 
until upgraded performance requirements are 
developed. However, because the agency does not 
want to delay providing the occupants of light 
trucks, buses and MPV's with the safety benefits 
of Standard No. 203, the agency is extending the 
standards to those vehicles while it continues to 
consider the feasibility of additional performance 
requirements. 

NHTSA is also considering possible additional 
requirements for Standard No. 201. The agency 
has scheduled a meeting for December 11, 1979, so 
that the public can present its views and ideas on 
ways of improving protection for children involved 
in vehicle collisions. In the September 4, 1979, 
notice announcing the meeting, the agency 
specifically asked for comments on possible 
improvements to the interior padding of vehicles to 
provide additional protection for children (44 FR 
51623). 

Heavy Trucks 

In the November 9, 1978 notice, NHTSA 
announced that it was evaluating whether to 
extend the applicability of Standards Nos. 201, 203 
and 204 to heavy trucks (i.e., trucks with a GVWR 
of more than 10,000 pounds) and solicited 
comments on appropriate performance 
requirements for those vehicles. In their com- 
ments, the Motor Vehicle Manufacturers Associa- 
tion, Freightliner and International Harvester all 
opposed an extension of the standards to trucks 
with a GVWR greater than 10,000 pounds, arguing 
that there is no data showing a safety need for 
applying the standards to those vehicles. They also 
argued that because of the size and weight of heavy 
trucks, occupants in these vehicles do not 
experience the same energy transfers in a crash 
than passenger car occupants experience and thus 
theoretically should incur fewer or less severe 



injuries. At the agency's recent meeting on heavy 
truck safety, several participants provided in- 
formation on the need for greater crash protection 
for drivers of heavy trucks. NHTSA is currently 
analyzing that information to determine what 
additional heavy truck regulatory action may be 
needed. 

Miscellaneous Comments 

MVMA pointed out that Standard No. 201 
currently requires two sun visors in a vehicle and 
requested that a second visor not be required if 
there is no front passenger seat. NHTSA agrees 
that such a change is appropriate and has made the 
necessary amendment to the standard. 

Jeep Corp. objected to the application of 
Standard No. 201 to open-body MPV's, arguing 
that for Jeep to locate padding in the expected 
head impact area it would have to raise its padding 
or lower its seat, both of which it claimed would 
interfere with the driver's forward visibility. 
Jeep's comment appears to reflect a misunder- 
standing of Standard No. 201. The performance 
requirements of the standard only apply to areas of 
the instrument panel that are within the head 
impact area of each designated seating position. 
(The head impact area is the portion of the 
vehicle's interior that can be contacted by a head- 
form representing an occupant's head.) Thus, if a 
portion of Jeep's vehicle instrument panel is not 
within the head impact area, it does not have to 
comply. For portions of the panel that are within 
the head impact area. Jeep can make structural 
changes to the instrument panel to meet Standard 
No. 201 without adding additional padding. 
Therefore, Jeep's requested exemption for all 
open-body vehicles is denied. 

One final stage manufacturer, Boyertown Auto 
Body Works, asked NHTSA whether its driver 
side instrument panel was within the exeptions to 
Standard No. 201 and, if not, sought to have its in- 
strument panel construed to be a console assembly, 
which is exempt from the standard. Such an inter- 
pretation is not acceptable since Boyertown clearly 
labels the area in question as an instrument panel 
in its engineering drawings. However, according 
to the engineering drawing provided by Boyer- 
town, the limited section on the instrument panel 
of concern to Boyertown is within the area 
exempted by S3. 1.1(d) of the standard. That 
section provides that the area of the interior 
immediately forward of the steering column is 
exempt from the standard. 



I 



PART 571; S 204-PRE-6 



Costs and Leadtime 

NHTSA has considered the economic and other 
impacts of this final rule and determined that they 
are not significant within the meaning of 
Executive Order 12044 and the Department of 
Transportation's policies and procedures for 
implementing that order. The agency's assessment 
of the benefits and economic consequences of this 
proposal are contained in a regulatory evaluation 
which has been places in the public docket. As 
explained previously, copies of the regulatory 
evaluation can be obtained by writing NHTSA's 
docket section at the address given in the begin- 
ning of this final rule. 

As previously detailed in this notice, the agency 
has examined the effectiveness of Standards Nos. 
201, 203 and 204 in passenger cars and concluded 
that those standards have brought about a substan- 
tial reduction in overall injuries occurring to the 
passengers in those vehicles. Because they share 
the same driving environment as occupants in 
passenger cars, occupants in light trucks, buses 
and MPV's face a similar risk of injury posed by 
hazardous instrument panels and rigid steering 
columns. Based on its evaluation of the effec- 
tiveness of Standards Nos. 201, 203 and 204 in 
passenger cars, the agency has concluded that 
applying those standards to light trucks, buses and 
MPV's can result in a reduction of 120 to 240 
fatalities and 4,400 to 8,900 serious injuries per 
year when all those vehicles comply with the 
standards. 

The agency's cost estimate for meeting 
Standards Nos. 201, 203 and 204 in light trucks, 
buses and MPV's take into account that many 
manufacturers have equipped some of their 
vehicles with components designed to meet the 
performance requirements of the standards. Those 
components may need little or no redesigning to 
fully comply with the standards. For example, 
American Motors, Chrysler, Ford, General 
Motors, International Harvester and Volkswagen 
commented that some, if not all, of their vehicles 
currently have components designed to comply 
with the standards or they will install such com- 
ponents in some of their vehicles by the 1981 model 
year. 

Only two manufacturers, Nissan and Ford, pro- 
vided any information about the costs associated 
with complying with the standards. Nissan said 



that the cost associated with complying with all 
three standards was $30. Ford estimated the cost 
for compliance with Standard No. 201 as $10 per 
vehicle; based on preliminary design assumptions. 
Ford put the cost of complying with Standards 
Nos. 203 and 204 in its van-type trucks, buses and 
MPV's at $120 per vehicle. 

To provide the agency with additional informa- 
tion about the estimated costs of complying with 
the three standards, NHTSA contracted with the 
John Z. DeLorean Corp. to evaluate current 
vehicles and determine what changes would be 
needed to bring the vehicles into compliance, Bases 
on its review of current foreign and domestic light 
trucks, buses and MPV's, DeLorean concluded 
that the total cost of compliance with the three 
standards would add a sales weighted average of 
$16 to the retail price of those vehicles. The 
DeLorean study reported that the vehicles requir- 
ing the most changes to meet Standards Nos. 201, 
203 and 204 were van-type trucks, buses and 
MPV's made by GM and Ford. DeLorean 
estimated that GM and Ford van-types vehicles 
would require a $27 increase in consumer price to 
comply with Standards Nos. 203 and 204 and a 
price increase ranging between $6 and $15 to 
comply with Standard No. 201. The agency 
believes that the substantial difference between 
DeLorean's and Ford's estimate of the cost of 
compliance with Standards Nos. 203 and 204 may 
be due to Ford's overestimate of the anticipated 
changes needed in the vehicles based on its 
preliminary design asssumptions. 

The agency's November 1978 notice proposed an 
effective date of September 1, 1980, for Standard 
No. 201 for all vehicles and for Standards Nos. 203 
and 204 for nonforward control vehicles. An effec- 
tive date of September 1, 1981, was proposed for 
Standards Nos. 203 and 204 for forward control 
vehicles to allow manufacturers additional time to 
make the necessary changes in those vehicles. In 
their comments on Standard 201, Chrysler and 
Ford said they could meet the standard in all their 
vehicles by the proposed effective date. Nissan, 
Toyo Kogyo and International Harvester (IH) 
requested from 18 to 24 months leadtime. General 
Motors requested 2V2 years' leadtime and 
American Motors requested 3 years. As a part of 
its NHTSA-funded study of the costs of complying 
with the standard, the DeLorean Corp. also 
examined the leadtime necessary to comply with 



PART 571; S 204-PRE-7 



the standard. For Standard No. 201, the DeLorean 
study concluded that only one year was needed for 
all vehicles except van-type trucks, buses and 
MPV's manufactured by Chrysler and GM, which 
needed two years. 

For Standards Nos. 203 and 204, Chrysler said 
that all its vehicles, except its incomplete forward 
control van-type vehicles, can comply by 
September 1, 1980. Chrysler did not provide an 
estimate of leadtime needed for its incomplete 
forward control vans. Nissan, Toyo Kogyo and IH 
requested from 18 to 24 months leadtime. Ford 
said its 1980 model year F-series trucks and 
Bronco models would comply with the standards 
and the Courier truck chassis cab imported by Ford 
would comply by September 1, 1981. Ford 
requested until September 1, 1982, for its van-type 
trucks, buses and MPV's. General Motors 
requested 2V2 years for all its vehicles and 
American Motors requested three years. 

The DeLorean study concluded that 18-24 
months of leadtime was needed for all models, 
except those made by Ford, which would require 
three years. DeLorean made its estimate of lead- 
time for Ford based on an assumption that Ford 



would need extra steering assembly tooling 
facilities. However, since Ford plans to introduce 
complying components on its 1980 model F series 
trucks and Bronco models, Ford has apparently 
developed the needed tooling capacity. 

Based on its analysis of the DeLorean study and 
of the industry's comments, NHTSA concludes 
that setting an effective date of September 1, 
1981, will allow sufficient time for all manufac- 
turers to comply with the standards. This action 
provides an additional year for all light trucks, 
buses and MPV's to meet Standard No. 201 and for 
nonforward control vehicles to meet Standards 
Nos. 203 and 204. 

The principal authors of this notice are William 
Smith, Office of Vehicle Safety Standards, and 
Stephen Oesch, Office of Chief Counsel. 

Issued on November 12, 1979. 



Joan Claybrook 
Administrator 



44 F.R. 68470 
November 29, 1979 



PART 571; S 204-PRE-8 



PREAMBLE TO AN AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD 

NO. 204 

Steering Control Rearward Displacement— Passenger Cars 

(Docket No. 3) 



ACTION: Final rule; correction. 

SUMMARY: On November 29, 1979, NHTSA 
published in the Federal Register a final rule 
extending the applicability of Standard No. 204, 
Steering Control Rearward Displacement, to light 
trucks, buses and multipurpose passenger vehicles 
with an unloaded vehicle weight of 4,000 pounds or 
less (44 FR 68470). In amendment number 5 on 
page 68475 describing the changes made to Stand- 
ard No. 204, the notice said that a new section S6 
was added to the standard. However, the notice 
did not provide the text for a new section S6. The 
reference to a new section S6 is an error. No such 
section was to be added to Standard No. 204. The 
purpose of this correction is to make clear that the 
only changes to Standard No. 204 are the amend- 
ments to sections S2 and S4 and the addition of a 



new section S5. All of those changes are fully 
described on page 68475 of the November 29, 1979, 
Federal Register notice. 

FOR FURTHER INFORMATION CONTACT: 

Mr. William Smith, Office of Vehicle Safety 
Standards, National Highway Traffic Safety 
Administration, 400 Seventh Street, S.W., 
Washington, D.C. 20590 (202-426-2242) 
Issued on January 28, 1980. 



Michael M. Finkelstein 
Associate Administrator 
for Rulemaking 

45 F.R. 7551 
February 4, 1980 



PART 571; S 204-PRE 9-10 



MOTOR VEHICLE SAFETY STANDARD NO. 204 
Steering Control Rearward Displacement— Passenger Cars 

(Docket No. 3) 



51. Purpose and scope. This standard specifies 
requirements limiting the rearward displacement 
of the steering control into the passenger compart- 
ment to reduce the likelihood of chest, neck, or 
head injury. 

52. Application. This standard applies to 
passenger cars and to multipurpose passenger 
vehicles, trucks and buses with a GVWR of 10,000 
pounds or less. However, it does not apply to walk- 
in vans. 

53. Definitions. 

"Steering shaft" means a component that 
transmits steering torque from the steering wheel 
to the steering gear. 

54. Requirements. Each passenger car and 
each multipurpose passenger vehicle, truck and 
bus with an unloaded weight of 4,000 pounds or 
less manufactured on or after September 1, 1981, 
shall meet the requirements of S5.1. 

S4.1 Except as provided in S4.2, the upper end 
of the steering column and shaft shall not be 
displaced horizontally rearward parallel to the 
longitudinal axis of the vehicle relative to an 
undisturbed point on the vehicle more than 5 
inches, determined by dynamic measurement, in a 
barrier collision test at 30 miles per hour minimum 
conducted in accordance with Society of 
Automotive Engineers Recommended Practice 
J850, "Barrier Collision Tests," February 1963. 



S4.2 A Type 2 seat belt assembly that conforms 
to Motor Vehicle Safety Standard No. 209 shall be 
installed for the driver of any vehicle with forward 
control configuration that does not meet the 
requirements of S4.1. 

S5. Rearward displacement requirements. 

S5.1 The upper end of the steering column and 
shaft shall not be displaced horizontally rearward 
parallel to the longitudinal axis of the vehicle 
relative to an undisturbed point on the vehicle 
more than 5 inches, determined by dynamic 
measurement, when the vehicle, loaded to its 
unloaded vehicle weight, is impacted perpen- 
dicularly into a fixed collision barrier at a forward 
longitudinal velocity of 30 miles per hour. 

Interpretations 

(1) When conducting the barrier collision test, a 
driver dummy may be used without measuring the 
impact force developed on the chest. 

(2) In the event that the vehicle impacts the 
barrier at a velocity not less than 30 miles per hour 
nor more than 33 miles per hour, the displacement 
of the steering column may be corrected to 30 
miles per hour by means of the following formula: 

Di Vi^ 

32 F.R. 2414 
February 3, 1967 



PART 571; S 204-1 



i 



€ 



EffKtIv*: S~ptamb*r 19, 19«l 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 205 

Glazing Materials — Passenger Cars, Multipurpose Vehicles, Motorcycles, Trucks, and 

Buses 

(Docket No. 9) 



Motor Vehicle Safety Standard No. 205 (32 
F.R. 2414) as amended (32 F.R. 10072) specifies 
requirements for glazing materials for use in 
passenger cars, multipurpose passenger vehicles, 
motorcycles, trucks, and buses. 

As a result of inquiries seeking clarification of 
the applicability of the Federal motor vehicle 
safety standards to campers, a ruling was pub- 
lished in the Federal Register on March 26, 1968 
(FHWA Ruling 68-1) (33 F.R. 5020) which 
specified that the glazing standard is applicable 
to slide-in campers because they are items of 
motor vehicle equipment for use in motor ve- 
hicles and to chassis-mount campers. 

The glazing standard requires that glazing 
materials "conform to the United States of 
America Standards Institute 'American Standard 
Safety Code for Safety Glazing Materials for 
Glazing Motor Vehicles Operating on Land 
Highways,' ASA Standard Z26.1— 1966." As a 
result, windshields and forward facing windows 
are required to be ASl laminated glass. 

The Federal Highway Administration has re- 
ceived petitions for rule making requesting that 
forward facing windows on campers be allowed 
to use AS2 or AS3 laminated glass which is able 
to meet the Z26.1-1966 penetration resistance test. 
No. 26, required of ASl type glass. The requests 
point out that ASl type glass which is presently 
required for forward facing windows in campers 
is unduly expensive and unnecessary for camp- 
ers because ASl type glass must meet stringent 
optical tests. The petitioners argue that forward 
facing windows on campers should not have to 
meet these stringent optical tests because the 
windows are not used for driver visibility. 

The Administrator has determined that grant- 
ing the petitions would not reduce the protection 



afforded the public by the standard. Accord- 
ingly the glazing standard is being amended to 
allow AS2 or AS3 laminated glass in forward 
facing windows of campers if the glass is able 
to meet the penetration resistance test. The 
amendment will require that forward facing 
windows in campers conform to ASl type lami- 
nated safety glass ; or AS2 type laminated safety 
glass that meets Test 26 of Z26.1-1966; or AS3 
type laminated safety glass that meets the re- 
quirements of Test 26 of Z26.1-1966. The latter 
two glazing materials will be identified by the 
characters AS2-26 and AS3-26 respectively. 

The Federal Highway Administration has re- 
ceived a petition for rule making requesting that 
Standard No. 205 be amended so that paragraph 
S3.2 Edges be changed to provide that exposed 
edges must meet the Society of Automotive Engi- 
neers Recommended Practice J673a, Automotive 
Glazing, August 1967, instead of the SAE Rec- 
ommended Practice J673, Automotive Glazing, 
June 1960. The petition also requests that the 
words "except that the minimum edge radius 
dimension shall not be less than the nominal 
thickness of the glazing material" be deleted 
because this requirement is already included in 
the SAE Recommended Practice J673a. These 
requests would allow minor imperfections in 
edging that would not diminish the safety bene- 
fits derived from the requirements but would 
allow normal manufacturing tolerances. These 
requests are granted and Standard No. 206 is 
being amended accordingly. 

The Administrator has received a petition 
concerning certification requirements for prime 
manufacturers of glazing materials; prime glaz- 
ing material manufacturers being those who fab- 
ricate, laminate or temper glazing materials. 



PART 571; S 205— PRE 1 



ElhcHva: $«pl*ml>«r 19, 1968 



The Petitioner states that he has encountered 
practical problems in the use of certification 
labels because: (a) glass stored for appreciable 
lengths of time, covered by the label, may 
"weather" in a different manner from the re- 
maining areas of the glass (b) labels on indi- 
vidual lights of glass can produce pressure points 
due to local area loading and may result in 
breakage during shipment and storage, and (c) 
certification labels can become separated from 
the material prior to delivery from consigned 
stock distributors to non-stocking distributors. 

The Petitioner points out that Standard No. 
205 requires marking of safety glazing materials 
in accordance with paragraph 6 of the United 
States of America Standards Institute (USASI) 
Standard Z26.1-1966. The Petitioner requests 
that the permanent marking on the glazing ma- 
terial required by Standard No. 205, with the 
addition of the symbol "DOT", be allowed as an 
alternative method of certification required under 
Section 114 of the National Traffic and Motor 
Vehicle Safety Act of 1966 (15 USC 1401). This 
petition is granted provided that the symbol 
"DOT" and an approved two digit manufac- 
turer's code number is included in the permanent 
marking. Any prime glazing material manu- 
facturer may apply for an approved two digit 



manufacturer's code number assignment to the 
Director, National Highway Safety Bureau, 
Washington, D.C. 20591. 

Since these amendments relieve restrictions, 
provide alternative means of compliance and 
create no additional burden the Administrator 
finds, for good cause shown, that it is in the 
public interest to make them effective upon date 
of issuance. 

In consideration of the foregoing, Section 
371.21 of Part 371, Federal Motor Vehicle Safety 
Standard No. 205 (32 F.R. 2414) as amended 
(32 F.R. 10072) is amended. . . . 

These amendments are made under the author- 
ity of Sections 103 and 119 of the National Traffic 
and Motor Vehicle Safety Act of 1966 (15 USC 
1392, 1407) and the delegation of authority con- 
tained in section 1.4(c) of Part I of the Regu- 
lations of the Office of the Secretary (49 CFR 
1.4(c)). 

Issued in Washington, D.C, on September 13, 
1968. 

John R. Jamieson, Deputy 
Federal Highway Administrator 

33 F.R. 14162 
September 19, 1968 



PART 571; S 205— PRE 2 



E«h<Hv«: March 1, 1969 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 205 

Glazing Materials 
(Docket No. 23; NoHce 2) 



Motor Vehicle Safety Standard No. 205 speci- 
fies requirements for glazing materials for usa 
in passenger cars, multipurpose passenger ve- 
hicles, motorcycles, trucks, and buses. 

As a result of inquiries seeking clarification 
of the applicability of the Federal motor vehicle 
safety standards to campers, a ruling was pub- 
lished in the Federal Register on March 26, 1968 
(33 F.R. 5020), which specified that the glazing 
standard (No. 205) is applicable to slide-in camp- 
ers because they are items of motor vehicle 
equipment for use in motor vehicles. 

Standard No. 205 requires, among other things, 
that glazing materials "conform to the United 
States of America Standards Institute 'American 
Standard Safety Code of Safety Glazing Ma- 
terials for Glazing Motor Vehicles Operating on 
Land Highways,' ASA Standard Z26.1-1966" 
(hereafter Z26.1-1966). 

By order published in the Federal Register on 
September 19, 1968 (33 F.R. 14162), section S3.2 
of the Standard was amended to allow the use 
of AS2 or AS3 laminated glass in forward facing 
windows of campers provided such glass met the 
requirements of Test 26 of Z26.1-1966. On the 
assumption that Z26.1-1966, as incorporated in 
Standard No. 205, required the use of ASl type 
laminated glass in forward facing windows of 
campers, the Administrator found that this 
amendment relieved restrictions, provided alter- 
nate means of compliance and created no addi- 
tional burdens. Accordingly, the amendment 
was made effective immediately. 

Thereafter, petitions for reconsideration were 
filed on the grounds, among others, that properly 
interpreted Z26.1-1966 permitted the use of ASl, 
AS2, AS3, AS4, and,AS5 glazing material in 
forward facing camper windows and that, there- 



fore, the September amendment did not relax an 
existing requirement but in fact imposed addi- 
tional testrictions upon manufacturers by limit- 
ing the types of glazing materials allowable for 
use in such windows. Consequently, it is urged 
that notice of that amendment should have been 
given and interested parties afforded an oppor- 
tunity to comment. 

The Administrator recognizes that, prior to 
the issuance of the September amendment, 
Standard No. 205 as initially promulgated could 
have been reasonably interpreted as allowing the 
use of ASl, AS2, AS3, AS4, and AS5 glazing 
materials in the forward facing windows of 
campers, that many manufacturers could have 
reasonably acted in reliance upon such a reading, 
that a great deal of confusion concerning the 
requirements has and continues to exist and that, 
in fact, comments focusing directly upon the 
proper glazing materials required in forward 
facing windows of campers have not been spe- 
cifically solicited by the Administration. In the 
light of all of these circumstances it is consid- 
ered appropriate to revoke section S3.2 — "Ma- 
terials for use in forward facing windows of 
campers" of Federal Motor Vehicle Safety 
Standard No. 205, as amended (33 F.R. 14162), 
as well as any interpretation that would have 
required the use of ASl glass only in forward 
facing camper windows. The net effect of this 
action is to permit, subject to further rulemaking 
action,' the use of glazing materials that peti- 
tioners represent are presently being used, i.e., 
ASl, AS2, ASS, AS4, and AS5 glazing materials 
referred to in Z26.1-1966. 

Since this amendment relieves restrictions and 
creates no additional burden the Administrator 
finds good cause is shown that an effective date 
earlier than 180 days after issuance in the 



PART 571; S 205— PRE 3 



EllKtIv*: March 1, 1969 

public interest and the amendment is made ef- 
fective upon date of issuance. 

In consideration of the foregoing, § 371.21 of 
Part 371, Federal Motor Vehicle Safety Standard 
No. 205 as amended (33 F.R. 14162) is amended 
by revoking S3.2 — "Materials for use in forward 
facing windows of campers". 

(Sees. 103, 119, National TraflSc and Motor 
Vehicle Safety Act of 1966 (15 U.S.C. 1392, 
1407) ; delegation of authority contained in 



§ 1.4(c) of Part 1 of the regulations of the Office 
of the Secretary (49 CFR 1.4(c) ) 
Issued : February 27, 1969. 

John R. Jamieson, Deputy 
Federal Highway Administrator 



' See notice of proposed rule making published at 
34 F.R. 3699, which proposes glazing requirements for 
forward facing windows of campers. 

34 F.R. 3688 
March 1, 1969 



PART 571; S 205— PRE 4 



EffMHva: April 1, 1973 

(Except at noted in th* Rule) 

Reissued: June 14, 1972 



PREAMBLE TO AMENDMENT TO MOTOR VEHICLE SAFETY STANDARD NO. 205 



Glazing Materials 
(Docket No. 71-1; Notice 3) 



The purpose of this notice is to amend Motor 
Vehicle Safety Standard No. 205, "Glazing Ma- 
terials," to permit the use of certain plastic ma- 
terials in motor vehicles in addition to those 
presently allowed ; to modify the certification and 
labeling requirements ; and to modify the test for 
tlie chemical resistance of plastic materials. It 
also clarifies the applicability of the standard to 
motor vehicle equipment, and the provisions of 
the standard dealing with readily removable 
windows. 

Federal Motor Vehicle Safety Standard No. 
205 was initially published February 3, 1967 (32 
F.R. 2414), and amended July 8, 1967 (32 F.R. 
10072), September 19, 1968 (33 F.R. 14162), and 
March 1, 1969 (34 F.R. 3688). On January 9, 
1971, a notice of proposed rulemaking (Docket 
71-1, Notice 1) was published based upon peti- 
tions for rulemaking received from the Eastman 
Chemical Products, Inc., and the California 
Highway Patrol. The former requested that the 
standard be amended to allow the use of butyrate 
plastic materials, and the latter requested changes 
in the requirements of the standard dealing with 
the marking of glazing materials. This amend- 
ment responds to both of these petitions and also 
modifies the stand&rd as a result of independent 
agency action. 

Standard No. 205 is applicable to "glazing ma- 
terials for use in passenger cars, multipurpose 
passenger vehicles, trucks, buses and motorcycles." 
It is also applicable, under FHWA Ruling 68-1 
(33 F.R. 5020, March 26, 1968), to glazing for use 
in slide-in and chassis-mount campers. This 
amendment to Standard No. 205 incorporates the 
substance of FHWA Ruling 68-1 into the appli- 
cability section of the standard and specifies, in 
accordance with the notice of March 1, 1969 
(Docket 23; Notice 2, 34 F.R. 3688) the glazing 



materials that are permitted to be used in these 
equipment items. 

The notice of January 9, 1971, proposed to re- 
vise the incorporation by reference of American 
Standards Association Test (ASA) Z26.1-1966 to 
include supplement Z26.1a-1969, March 7, 1969, 
and to reflect the change in the name of the Amer- 
ican Standards Association to the American Na- 
tional Standards Institute. No objections were 
raised in the comments to these proposals, and 
they are incorporated into the standard by this 
amendment. 

The notice proposed to modify the chemical re- 
sistance tests incorporated into the standard 
(Tests 19 and 20), by deleting carbon tetrachlo- 
ride as a testing agent and by adding trichlor- 
ethylene. The tests are designed to test the 
resistance of plastic materials to chemicals that 
are commonly used to clean them. By this notice, 
carbon tetrachloride is deleted from the list of 
materials. As indicated in the notice of proposed 
rulemaking, the deletion is commensurate with 
the ban imposed by the Food and Drug Admin- 
istration on this substance because of its high 
toxicity. At the same time, the NHTSA has de- 
cided not to include either trichlorethylene or 
freon in the list of testing agents. The comments 
have indicated that these substances are not com- 
monly used as cleaning agents, and accordingly 
they are not used for test purposes. 

The major revision proposed by the notice, 
based upon a petition for rulemaking from the 
Eastman Chemical Products Co., Inc., was to al- 
low additional plastic materials to be used in 
motor vehicles. The petitioner claimed that the 
requested materials would meet any test to which 
other plastic materials are subjected, except for 
resistance to undiluted denatured alcohol (For- 



PART 571; S 205— PRE 5 



EffKtIv*: April 1, 1973 
(Except as noted in the Rul*) 
RaUsuad: June 14, 1972 



mula SD 30), where a slight tackiness would oc- 
cur. Rather than merely exempt these plastics 
from the alcohol resistance requirement, the no- 
tice suggested that they still be subjected to the 
same chemicals as other plastics, but that if 
structural integrity were maintained, a loss of 
transparency would be allowed. The notice for 
the same reason proposed not to subject these 
materials to the abrasion and weathering tests 
applied to other plastics. Instead, the proposal 
would have required labels to be affixed to the 
material specifying cleaning agents and instruc- 
tions that would minimize loss of transparency, 
and would have restricted them to locations in 
motor vehicles where loss of transparency would 
not affect driver visibility. 

Based upon information received during the 
rulemaking process, the NHTSA has determined 
that the materials in question exhibit character- 
istics which make them satisfactory