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

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Federal Motor Vehicle Safety
Standards and Regulations

^,!ra°n?p?S Supplemepit 51— Amendments

jfX'sST" and Interpretations Issued

Administration -i-i i j r\r\r\

Through 1992 i^mmBmnitr

TD8.6/2:992/SUPP.51 ^ i Sn^lfe^

Page Control Chart

Federal Hotor Uefcicle Safetg Standa... ^ DEC f 7 ^93

(1) Federal Motor Vehicle Safety Standard No. 105 , ' V^UUutJUMHv

(a) Insen attached pages numbered PART 571; S 105— PRE 113 through PRE 123 behind page m't)t5Wminilwitqi)|t)ir
PART 571; S105-PRE 111-112.

(b) Substitute attached Standard 105 for Standard 105 in book.

(2) Federal Motor Vehicle Safety Standard No. 108

(a) Insert attached pages numbered PART 571; S108-PRE 391 through PRE 404 behind page in book numbered
PART 571; S108-PRE 389.

(b) Substitute attached Standard 108 (except for Art Pages) for Standard 108 in book.

(3) Federal Motor Vehicle Safety Standard No. 1 1 1

• (a) Insert attached pages numbered PART 571; Slll-PRE 29 through PRE 57 behind page in book numbered

PART572;S111-PRE28.
(b) Substitute attached Standard 111 for Standard 1 1 1 in book.

(4) Federal Motor Vehicle Safety Standard 121

(a) Insert attached pages numbered PART 571; S121-PRE 223 through PRE 239 behind page in book numbered
PART 571; S121-PRE 222.

(b) Substitute attached Standard 121 for Standard 1 2 1 in book.

(5) Federal Motor Vehicle Safety Standard No. 131

(a) Insert attached pages numbered PART 571; S131-PRE 13 through PRE 16 behind page in book numbered
PART 571; S131-PRE 12.

(b) Substitute attached Standard 131 for Standard 131 in book.

(6) Federal Motor Vehicle Safety Standard No. 213

(a) Insert attached pages numbered PART 571; S213-PRE 73 through PRE 91 behind page in book numbered
PART 571; S213-PRE 71-72.

(b) Substitute attached Standard 213 for Standard 213 in book.

(7) Federal Motor Vehicle Safety Standard No. 214

(a) Insert attached pages numbered PART 571; S214-PRE 75 through PRE 87 behind page in book numbered
PART571;S214-PRE74.

(b) Substitute attached Standard 214 for Standard 214 in book.

(Continued on reverse)

^P The Federal Motor Vehicle Safety Standards and amendments published In this format are for reference purposes

only. They should not be considered as legally binding or be used as a source of authority In matters of litigation.
The United States Code of Federal Regulations is the only source of legal authority for the standards.

(8) Federal Motor Vehicle Safety Standard No. 217

(a) Insert attached pages numbered PART 571: S217-PRE 23 through PRE 47 behind page in book numbered
PART571;S217-PRE22.

(b) Substitute attached Standard 217 for Standard 217 in book.

(9) Part 572 — Anthropomorphic Test Dummies

(a) Insert attached page numbered PART 572-PRE 103 behind page in book numbered PART 572-PRE 102.

(b) Substitute attached PART 572 for PART 572 in book.

(10) PART 586— Side Impact Protection

(a) Insert attached pages numbered PART 586-PRE 5 through PRE 15 behind page in book numbered PART
586-PRE 4.

(b) Substitute attached PART 586 for PART 586 in book.

(11) PART 588— Child Restraint Systems Recordkeeping

Insert attached pages numbered PART 588-PRE 1 through PART 588-1 behind page in book numbered PART

587-2.

(12) PART 591 — Importation of Vehicles and Equipment Subject to Federal Safety Bumper and Theft

Protection Standards

(a) Insert attached page numbered PART 591 -PRE 51 behind page in book numbered PART 591 -PRE 50.

(b) Substitute attached PART 591 for PART 591 in book.

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR

VEHICLE SAFETY STANDARD NO. 105

Hydraulic Brake Systems

(Docket No. 91-21; Notice 2)
RIN: 2127 -AD34

ACTION: Final rule.

SUMMARY: This rule amends Federal Motor
Vehicle Safety Standard No. 121, Air Brake Sys-
tems, to require automatic brake adjusters on all
air-braked vehicles and adjustment indicators on
air-braked vehicles with external adjustment
mechanisms. This rule also amends Standard No.
105, Hydraulic Brake Systems, to require auto-
matic brake adjusters on vehicles with hydraulic
brake systems. However, the rule does not require
adjustment indicators on hydraulically-braked
vehicles because there do not appear to be signifi-
cant problems with monitoring automatic brake
adjusters on such vehicles. These amendments
should improve the braking performance of
vehicles by ensuring that their brakes are properly
adjusted.

DATES: Effective Dates: The amendments to
Standard No. 105 become effective October 20,
1993.

The amendments to Standard No. 121 become
effective October 20, 1994.

SUPPLEMENTARY INFORMATION:

Background

General Information
Proper brake adjustment is critical for maintain-
ing safe stopping performance. Devices known as
automatic brake adjusters automatically maintain
proper brake adjustment, thus eliminating the
need for frequent inspection and manual adjust-
ment of the brakes. Automatic brake adjusters
have been used on passenger cars and light trucks
since the early 1960s and have been standard
equipment on all such vehicles sold in recent
years in the United States. In addition, the vast
majority of medium and heavy duty vehicles with
hydraulic brake systems have automatic brake

adjusters. Automatic brake adjusters were intro-
duced for use on heavy duty air-braked vehicles
in the early 1960s and are widely used today. The
installation rates of automatic brake adjusters by
manufacturers of heavy duty air-braked vehicles
range from 30 to 100 percent of their fleets.

Safety Need and Practicability of Automatic
Adjustment Devices

Notwithstanding the importance of proper brake
adjustment for maintaining safe stopping perform-
ance, numerous studies have shown that brake
adjustment is not being maintained on some air-
braked medium and heavy duty vehicles that are
not equipped with automatic brake adjusters. (See
Automatic Slack Adjusters for Heavy Vehicle Air
Brake Systems, DOT HS 807 724, February
1991.) When brakes are under-adjusted, stopping
ability is reduced and the probability of a crash
is increased. When brakes are over-adjusted,
maintenance costs and the possibility of a crash
are increased as a result of excessive lining wear,
wheel lock, or brake drum cracking. Such
improper brake adiustment contributes to a
significant number of crashes, including those in
which vehicles are unable to stop in time and
those in which there are "runaways" on steep
mountain grades.

As detailed in the notice of proposed rule-
making (NPRM) for this rulemaking (56 FR
20396, May 3, 1991), several studies highlight the
problems associated with improper brake adjust-
ment, especially on air-braked vehicles. These
studies include the Office of Technology Assess-
ment's (OTA's) September 1988 report Gearing
Up for Safety, NHTSA's March 1987 Heavy
Truck Safety Study Report to Congress, the
National Transportation Safety Board's investiga-
tions of heavy truck crashes, and a Federal High-
way Administration study.

PART 571; S105— PRE-113

Based on the above-mentioned concerns, the
National Transportation Safety Board rec-
ommended that NHTSA develop a Federal Motor
Vehicle Safety Standard requiring all newly
manufactured commercial vehicles to have equip-
ment ensuring that brakes are always properly
adjusted.

Automatic brake adjusters are now used on
approximately 60 percent of new medium and
heavy duty vehicles with air brakes. However,
one major, and a number of smaller vehicle
manufacturers, do not provide automatic brake
adjusters as standard equipment, and many pur-
chasers do not order them as optional equipment.

NHTSA believes that automatic brake adjuster
use has stabilized at about the current 60 percent
level. NHTSA has conducted a large-scale fleet
evaluation to assess the performance and reliabil-
ity of automatic brake adjusters, as compared to
manual adjusters on heavy commercial vehicles
with S-cam air brakes. NHTSA collected brake
adjustment data from several hundred fleet
vehicles equipped with automatic and manual
brake adjusters for approximately five years. The
conclusions regarding the fleet examination are
detailed in the NPRM. Among the principal
conclusions were that:

• Automatic brake adjusters generally maintained
brake adjustments within the limits specified by
the vehicle manufacturer. The medium percent-
age of out-of-adjustment brakes for the fleet
applications was about four percent. This rep-
resents a far lower out-of-adjustment rate than
is commonly found in roadside check studies of
brake adjustment for manually-adjusted air
brakes.

• In the most successful applications, automatic
brake adjusters consistently exhibited out-of-
adjustment percentages of less than one per-
cent. Thus, automatic brake adjusters dem-
onstrated the potential for very effective
performance levels.

• The incidence of brake over-adjustment with
automatically-adjusted brakes was low. In the
fleet test, there was no case of an automatic
brake adjuster over adjusting a brake enough to
cause brake over-heating, wheel lockup, or
excessive brake lining wear.

Automatic Adjusters and Indicators
on Air Brake Systems

There are three principal types of air-braked
systems used in this country: 1) S-cam actuators,
2) wedge type actuators, and 3) disc brakes. For
S-cam brakes, which comprise about 95 percent
of air-brake systems, two major types of auto-
matic brake adjusters are available. One adjusts
on the basis of actual shoe-to-drum clearance. The
other adjusts on the basis of the air chamber push
rod stroke. All wedge type brakes, which com-
prise about three percent of the market, have an
internal automatic adjustment mechanism. As for
disc brakes which comprise about two percent of
air-brake systems, some have external self-adjust-
ing mechanisms, while others have internal
adjustment features. The external adjustment
mechanism of an air disc brake system operates
similarly to those on S-cam brakes.

Brake adjustment indicators improve brake
adjustment by increasing the convenience of
checking brake adjusters and their proper func-
tioning. Without brake adjustment indicators,
measuring brake adjustment requires following a
laborious and time-consuming manual procedure
in which the push rod length must be measured
before and during brake application. The proce-
dure is especially difficult for brake chambers
located at positions under the vehicle that are dif-
ficult to reach. Also, a person checking brake
adjustment must know the specific adjustment
data for each chamber because some manufactur-
ers have slightly different stroke lengths for the
same size chamber. The procedure is also com-
plicated because the chamber's make and model
may be difficult to identify when it is covered
with road dirt and corrosion.

Several types of brake adjustment indicators are
cuiTently available. One type involves air brake
chambers with paint markings on push rods that
indicate the level of adjustment. However, such
markings may not be useful in certain applica-
tions (e.g., with wedge brakes when the push rod
is enclosed in a sleeve and with S-cam brakes
having push rods with protective rubber boots). A
second type of brake adjustment indicator is
installed by inserting a guide arm and sliding
stem assembly into a small hole in the air booster
can. A third method involves attaching a hose
clamp to the air chamber push rod to mark the

PART 5/1: S105— PRE-114

fully adjusted brake position relative to the air
chamber housing. To check the brake adjustment,
the space between the air chamber housing and
hose clamp is compared with a bar gauge.

Notice of Proposed Rulemaking

On May 3. 1991, NHTSA published an NPRM
in which the agency proposed to amend Standard
No. 121 to require automatic brake adjusters and
adjustment indicators on vehicles with air brake
systems. (56 FR 20396) The NPRM also pro-
posed to amend Standard No. 105 to require auto-
matic brake adjusters on vehicles with hydraulic
brake systems. NHTSA decided not to propose
requiring adjustment indicators on hydraulically-
braked vehicles because the agency believed that
there were no significant problems with automatic
brake adjusters for these vehicles or with check-
ing the adjustment of such systems.

Among the issues discussed in the NPRM were
(1) the need to require automatic brake adjusters
in passenger cars and other hydraulically braked
vehicles, (2) specific provisions in the proposed
language to require automatic brake adjusters on
passenger cars, (3) the need for automatic brake
adjusters on air-braked vehicles to correct for
both under and over-adjustment, (4) the apparent
absence of a need for automatic adjustment
indicators for hydraulically braked vehicles, (5)
visibility requirements for adjustment indicators
on air-braked vehicles, (6) the necessary leadtime
for the proposal, and (7) the costs associated with
the rulemaking.

Comments to the NPRM and the
Agency's Response

NHTSA received about 35 comments in
response to the NPRM. These were from vehicle
manufacturers, brake manufacturers, manufactur-
ers of brake adjusters and adjustment indicators,
heavy vehicle users, trade associations, and oth-
ers. The majority of commenters generally agreed
with the proposal to require brake adjusters on
both hydraulic and air-braked vehicles and to
require adjustment indicators on air-braked
vehicles. In addition, commenters addressed spe-
cific matters in the proposed regulation, including
the issues of over-adjustment, visibility require-
ments, and other provisions in the proposed regu-
latory text.

The agency has considered the points raised by
the commenters in developing the final rule. The

agency's discussion of the more significant com-
ments and other relevant information is set forth
below. The notice first addresses issues about
automatic adjusters and indicators on vehicles
equipped with air brakes because the safety prob-
lem primarily involves, and consequently the
agency's rulemaking efforts focus on, these
vehicles. The notice then discusses adjustment
devices on hydraulically-braked vehicles.

Air-Braked Vehicles

1. General Considerations

As explained above, the safety problem with
out-of-adjustment brakes primarily involves air-
braked vehicles. Accordingly, the agency's rule-
making efforts have focused on requiring auto-
matic adjusters and adjustment indicators on such
vehicles.

In response to the NPRM's proposal to require
automatic adjusters on air-braked vehicles, all but
one commenter addressing this issue supported
requiring automatic adjusters on air-braked
vehicles. Those supporting the rulemaking
included the American Trucking Associations
(ATA). Truck Trailer Manufacturers Association
(TTMA), General Motors (GM), Ford, and Advo-
cates for Highway and Auto Safety (AHAS).
AHAS stated that the amendments would mitigate
the extent and severity of fatal and injury produc-
ing accidents. Only one commenter, Mr. Robert
Crail, a brake consultant, disputed the need for
and effectiveness of automatic adjusters on air-
braked vehicles. Mr. Crail stated that automatic
adjusters are not accurate enough to be mandated,
citing raw data about automatic slack adjusters.

Based on the comments and other available
information, NHTSA has determined that requir-
ing automatic adjusters on air-braked vehicles will
improve the brake performance of these vehicles.
As the NPRM explained, out-of-adjustment brakes
pose a significant safety problem that could be
alleviated by requiring automatic brake adjusters.
The agency notes that Mr. Crail's critical com-
ments were based, in part, on raw data gathered
from unscreened sources and uncontrolled test
conditions. Therefore, his conclusions based on
the data are questionable. While NHTSA
acknowledges that older brake adjuster designs
may not perform as well as properly maintained
manual adjusters, the new generation of currently
produced automatic adjusters provide superior
brake adjustment. In addition, even the previous

PART 571; S105— PRE-115

generation of automatic brake adjusters are often
superior to manual adjusters because some owners
of vehicles with manual adjusters do not take the
time to properly adjust or otherwise properly
maintain their brakes.

2. Proposed Regulatory Text
The NPRM proposed amending Standard No.
121 to require all vehicles with air brakes to be
equipped with automatic adjusters. Specifically,
the NPRM proposed that the standard be amended
to require these devices on trucks, buses, and
trailers, as follows:

Each vehicle shall be equipped with a service
brake system acting on all wheels. Wear of the
service brakes shall be compensated for by
means of a system of automatic adjustment,
which maintains brake adjustment within the
manufacturer's recommended adjustment limits.
The condition of service brake adjustment shall
be provided by a brake adjustment indicator
that is discernible when viewed with 20/40
vision, using an ordinary flashlight with two D-
cell batteries from a position 8 feet away on
the adjacent pavement surface. The brake
adjustment indicator shall be capable of
displaying the service brake adjustment condi-
tions of: under-adjustment, over-adjustment,
and fully adjusted within the manufacturer's
specified limits.

Commenters addressed various aspects of the
proposed regulatory text, including specifying that
brake adjustment be maintained within the manu-
facturer's recommended adjustment limits, having
adjusters correct for under and over adjustment,
having indicators display the conditions of under,
over, and full adjustment, and having visibility
requirements. Along with the comments address-
ing each of these considerations, the agency's
response to the comments is presented below.

a. Brake Adjustment within Manufacturer' s
Recommended Adjustment Limits

As explained above, the NPRM proposed that
brake adjustment would have to be maintained
"within the manufacturer's recommended adjust-
ment limits." The agency had tentatively believed
that requiring adjustment within the manufactur-
er's recommended adjustment limits would pro-
vide a more specific performance requirement.

Several commenters, including White GMC/
Volvo, GM, Ford, Midland-Grau, and a brake
indicator manufacturer, criticized the proposal to

require maintaining brake adjustment within the
manufacturer's recommended adjustment limits. ^^
These commenters believed that the proposal was ^H
unnecessary, ambiguous, and would unreasonably
burden manufacturers. GM and Ford stated that
the proposal was potentially ambiguous since
determining what "maintaining brake adjust-
ment" means could be interpreted several ways.
Accordingly, these commenters believed that
some compliance test would be necessary if the
agency adopted this provision. White GMC/
Volvo, GM, and Ford believed that the proposal
might be interpreted as requiring the manufacturer
to be responsible for brake adjustment throughout
the vehicle's life, even though the manufacturer is
typically responsible for compliance only until the
first consumer purchase. In addition, some com-
menters were concerned that the proposal did not
specify an objective measure about the proper
level of adjustment. This consideration led Mid-
land-Grau to recommend that the standard incor-
porate the Federal Highway Administration's
requirements in appendix G to subchapter B of
Chapter III, Title 49, Code of Federal Regula-
tions. FHWA, based on input from the Commer-
cial Vehicle Safety Alliance and brake chambers ^M
manufacturers, has established a set of brake ^B
adjustment tables that are published in the North
American Uniform Vehicle Out-of-Service Cri-
teria. The States rely on these roadside inspection
tables to place a vehicle out of service if the
adjustment limits are exceeded.

After reviewing the comments and the available
infomiation, NHTSA has determined that the final
rule should not include a reference to maintaining
adjustment within the manufacturer's rec-
ommended limits. The agency agrees with com-
menters that such a provision would not provide
any significant safety benefits but might cause
unnecessary complications and confusion. In
terms of safety benefits, the final rule addresses
the most important issue by requiring each
vehicle to be equipped with a service brake sys-
tem including means for automatic adjustment to
compensate for wear of the system. The reference
to the manufacturer's adjustment limits would
have been superfluous and potentially confusing.
Nevertheless, as explained below, the agency has
decided to reference the FHWA's regulations ^

about "Vehicle Out-of-Service Criteria." By not fl
including reference to maintaining adjustment
based on the manufacturer's recommendations.

PART 3/1; SI 05— PRE- 11 6

this amendment is consistent with the proposed
requirement about brake adjustment in Standard
No. 135, Passenger Car Braise Systems. (56 FR
30528, July 3, 1991). Accordingly, the final rule
specifies that "Wear of the service brakes shall
be compensated for by means of a system of
automatic adjustment," without reference to a
manufacturer's adjustment limits. The agency
notes that there is no objective criteria as to what
constitutes "maintains adjustment." In addition,
as a general rule, the agency does not establish
extended durability testing. The agency believes
that to require that the adjustment be maintained
throughout the lifetime of the vehicle is unrealis-
tic, dependent upon the vehicle's exposure, and
beyond the scope of NHTSA's authority.

As for Midland-Grau's recommendation to use
FHWA's regulations for "Driver Out-of-Service
Criteria" for brake adjustment, NHTSA has
decided to reference these provisions in Standard
No. 121 because they are relevant to in-use heavy
truck operation regulated by FHWA. Because
amendments to Standard No. 121 require the use
of brake adjustment indicators which require the
display of underadjustment, a reference to adjust-
ment limits is necessary. Those limits are speci-
fied in Appendix G to Subchapter B of Chapter
III, 49 CFR Parts 200 to 399.

b. Brake Over-adjustment and Under-adjiist-
ment

The NPRM tentatively concluded that auto-
matic brake adjusters should have the capability
of correcting for both under and over-adjustment.
The NPRM also proposed that a brake adjustment
indicator be capable of displaying the brake
adjustment conditions of under-adjustment, over-
adjustment, and fully adjusted. The notice
requested comments about whether these require-
ments were feasible and whether they should be
specified in the regulatory text.

Twelve commenters, primarily heavy brake and
vehicle manufacturers, opposed requiring brake
adjusters to correct for over-adjustment. These
commenters also opposed requiring the brake
adjustment indicators to identify the over-adjusted
and fully adjusted conditions. User groups, such
as the Owner-Operator Independent Drivers
Association supported these proposals. Navistar,
Haldex, Bendix, Midland-Grau, Rockwell, Ford,
the MVMA, Chrysler, Eaton, and the ATA
believed that requiring the device to control for
over-adjustment and having the adjustment indica-

tor identify this condition were unnecessary and
impracticable. MVMA stated that the incidence of
over-adjustment is very infrequent and poses a
minimal risk to safety. In addition, several manu-
facturers explained that the condition of over-
adjustment can be ascertained by excessive wear,
abuse of the equipment, and in extreme cases,
smoke. The commenters also stated that the pro-
posal was impracticable because there was no
current technology that reliably indicates the over-
adjusted condition. After reviewing the comments
and available infomiation, NHTSA concludes that
requiring brake adjusters to correct for over-
adjustment and having adjustment indicators show
the over-adjusted and fully-adjusted conditions are
unnecessary for safety and would be impractica-
ble. In terms of the safety need, the fleet evalua-
tion cited in the NPRM concluded that the
incidence of brake over-adjustment was extremely
low. NHTSA further notes that potential problems
associated with over-adjustment will not be
significant. The driver typically will be aware of
over-adjustment because the brake system will
drag and may begin to smoke. In terms of prac-
ticability, the NPRM's tentative determination
about the availability of automatic brake adjusters
to correct for over-adjustment appears to be
inconsistent with the current state of brake tech-
nology. The agency now agrees with the com-
ments that regulating over-adjustment would be
impracticable given that such devices are not
readily available. Based on the above, the final
rule does not require brake adjusters to correct for
over-adjustment and does not require the adjust-
ment indicators to show the over-adjusted and
fully-adjusted conditions.

As for the condition of under-adjustment, most
commenters, including Rockwell, MVMA, Ford,
and GM believed that the agency should intro-
duce requirements to prevent this brake condition.
MVMA stated that the primary motivation and
safety benefit underlying automatic brake adjust-
ers is to minimize the incidence of under-adjust-
ment.

After reviewing the comments and the available
information, NHTSA has decided to adopt provi-
sions requiring brake adjusters to correct for the
condition of service brake under-adjustment and
have a device that indicates the under-adjusted
condition. The agency agrees with the com-
menters that under adjustment poses a significant
risk to safety. In addition, NHTSA believes that

PART 571; SI 05— PRE-

this requirement is practicable since there cur-
rently are several devices that are capable of
indicating the under-adjusted condition. Accord-
ingly, Sections 5.1.8 and S5.2.2 are amended to
read, in relevant part, '"(b) Brake indicator. .. the
condition of service brake under-adjustment shall
be provided by a brake adjustment indicator ...

c. Visibility' Requirements for Brake Adjust-
ers

The NPRM proposed that the brake adjustment
indicator be discernible when viewed with 20/40
vision, using an ordinary flashlight with two D-
cell batteries from a position at least eight feet
away on the adjacent pavement surface. The
agency believed that these visibility requirements
would allow a person to check brake adjustment
without having to crawl under the vehicle.

Commenters offered various views about the
proposed visibility requirements. Manufacturers of
aftermarket add-on indicators favored the pro-
posal, while vehicle manufacturers and custom
builders objected. Users of brake equipment
offered mixed views.

Several commenters, including Mack, Navistar,
GM, the National Truck Equipment Association
(NTEA), Haldex, the Truck Trailer Manufacturers
Association (TTMA), and Flxible stated that the
proposed visibility requirements were impractica-
ble, especially for those vehicle configurations in
which the line of sight to the air brake chambers
is obscured. In many vehicles, including buses,
beverage haulers, walk-in vans, ambulances, low-
bed trucks, utility trailers, and tank-trucks, the
brake adjustment indicator may only be inspected
by crawling under a vehicle. Mack explained that
many vehicle configurations make it difficult or
impossible to view the chamber from eight feet
away because brake chambers are frequently
located in positions that are obscured by tires,
hoods, and other vehicle components. In addition,
Rockwell stated that in-service environmental fac-
tors such as mud, salt, and grease would prevent
the reading of the adjustment indicator unless the
chamber were wiped off.

These practicability concerns with the proposed
visibility requirements led commenters to rec-
ommend modifying the proposal. GM rec-
ommended a simplified requirement in which the
indicator would have to be discernible when
viewed with 20/40 vision from outside or the
underside of the vehicle. Ford suggested that the

visibility requirement allow inspection from either
side of or under the vehicle.

After reviewing the comments, NHTSA has^
decided not to adopt the detailed visibility pro-
posal because the requirement would raise signifi-
cant practicability problems. The agency notes
that the proposed eight foot requirement would
necessitate extensive redesign of certain vehicle
configurations such as drop floor and moving
vans. In addition, the proposed visibility require-
ment would be impracticable for evaluating brake
adjusters that have been covered by road contami-
nants such as dirt, grime, and snow. NHTSA
believes that by not adopting the eight foot view-
ing requirement, the standard will encourage
closer hands-on inspection of the equipment.
Based on the above considerations, the agency
has decided not to require that the adjustment
indicator be readable at a distance of eight feet.
The visibility provision now states that "the
condition of service brake under-adjustment shall
be provided by a brake adjustment indicator that
is discernible when viewed with 20/40 vision
from a location adjacent to or underneath the
vehicle."

d. Vehicle Type ^

The NPRM proposed that all air-braked
vehicles be equipped with an adjustment indica-
tor, regardless of brake system type. The NPRM
explained that there were three principal types of
air brake systems: S cam brakes which account
for 95 percent of the brake market; wedge type
brakes, three percent of the market; and disc
brakes, two percent of the market. While S cam
brakes have external adjustment mechanisms,
wedge brakes and some disc brakes have internal
mechanisms.

Several commenters, including Volvo GM
Heavy Truck, Navistar, GM, Bendix, Rockwell,
and MVMA, stated that adjustment indicators are
only practicable with external adjustment designs
such as S cam brakes with exposed push rods.
MVMA stated that there was little if any need to
require adjustment indicators on internally
adjusted brakes. Like hydraulic brakes, air-brake
systems with internal adjustment designs would
have to be significantly redesigned to incorporate
an adjustment indicator. Rockwell believed that
the nominal benefits from having wedge brakes
and internally adjusted disc brakes equipped with
indicators did not wanant the significant costs
that would be needed to redesign these systems.

PART 571; S105— PRE-lli

Bendix and Lear Siegler explained that some

(external actuators are equipped with a protective
boot or a scraper seal.

After reviewing the comments and the available
information. NHTSA has determined that
although all air brakes should have a system of
automatic adjustment, it is not necessary to
require adjustment indicators on internally
adjusted brakes. The agency is not aware of any
significant adjustment problems with internally
adjusted brakes. In addition, such a requirement
for these designs would not be practicable given
the significant feasibility concerns and redesign
costs to require an adjustment indicator on
internally adjusted brake systems. The agency
notes that S cam brakes, except the approximately
one percent that have protective pushrod boots,
have exposed air chamber pushrods which easily
can be marked to indicate brake adjustment.

S cam brakes whose pushrods are covered
by protective boots cannot be simply marked,
since the markings would not be visible to outside
inspection. The NPRM did not propose to exempt
booted systems from having to have adjustment
indicators, describing two designs that have the
potential to indicate adjustment of such systems.
In commenting to the docket, Lear Siegler, a
major air chamber manufacturer, stated that air
brake actuators equipped with protective boots
should be exempt from adjustment indication in
its current technological form. Bendix commented
that brake actuators with pushrod boots or scraper
seals should be exempted.

After a review of the comments to the docket
and other information on this issue, the agency
has decided not to require adjustment indicators
on service brake systems that have pushrod boots.
Systems having scraper seals and exposed
pushrods will be required to have adjustment
indicators, since the pushrods can be easily
marked and inspected. Brake acmators with
pushrod boots are made to provide performance
and reliability under severe operating conditions,
such as corrosive or hazardous material handling
and refuse collection and disposal. The heavy-
duty, durable adjustment indicators, adequately
integrated into the actuator system, that would be
necessary to withstand these severe operating
environments, would cost substantially more than
indicators on exposed pushrods. Brake systems
with pushrod boots account for perhaps one per-
cent of the brake actuator market, as previously

noted. These systems are being required to have
automatic brake adjusters. Further, many booted
systems are used with rolling diaphragm brake
chambers (roto chambers) that have longer strokes
than conventional chambers and thus provide a
greater operating range for automatic slack adjust-
ers and a longer period of use before the
underadjustment condition is reached. While the
agency is not requiring brake systems with booted
pushrods to have adjustment indicators, it would
revisit this issue if the number of these systems
increase substantially in the future. Thus, the
agency is only requiring externally adjusted
brakes with exposed pushrods to be equipped
with adjustment indicators. The agency estimates
that about 94 percent of air brakes will be
equipped with indicators.

3. Miscellaneous Concerns

Several commenters, including brake indicator
manufacturers and user groups, requested that the
agency require air-braked vehicles that are cur-
rently in use to be retrofitted with automatic
adjusters and adjustment indicators. NHTSA notes
that the National Traffic and Motor Vehicle
Safety Act of 1966 (15 U.S.C. 1381) authorizes
the agency to promulgate safety standards for new
vehicles only. The Act does not provide the
agency with out authority to require the retro-
fitting of in-use vehicles. Therefore, the agency
cannot require in-use vehicles to be equipped with
automatic brake adjusters or adjustment indica-
tors.

Flxible commented that it should be allowed
the option of using manual slack adjusters during
its certification testing. NHTSA notes that Flxible
can do whatever it wants in its compliance test-
ing, if it can establish, should it become necessary
to do so, that use of its test procedure constitutes
due care. Nevertheless, NHTSA believes that
Flxible may have difficulty establishing due care
if it uses manual adjusters during its certification
testing, because an earlier rulemaking prohibited
the disconnecting of automatic adjusters during
agency compliance testing. (54 FR 40080,
September 28, 1989). That notice explained that
an important purpose behind the test conditions
and procedures is to test vehicles as they will per-
form when used on the road. Since automatic
brake adjusters are operational during normal use,
specifying that they be operational during agency
compliance testing helps approximate real-world

PART 571: S105— PRE-1 19

conditions and provides a better test of real-world
performance.

Advocates for Highway and Auto Safety asked
whether dollies are required to be equipped with
automatic adjusters and adjustment indicators
under the proposals. The requirement for auto-
matic adjusters and adjustment indicators is
applicable to dollies since section 571.3 defines a
"trailer converter dolly" as "a trailer chassis
equipped with one or more axles, a lower half of
a fifth wheel and a drawbar." Since trailer chassis
are trailers and trailers are subject to the require-
ment, trailer converter dollies also are subject to
the requirement.

The ATA requested an exclusion from the
automatic adjuster requirements for vehicles
involved in "permit" operations such as
transporting hazardous waste and explosives.
While NHTSA has the authority to set standards
based on vehicle type, it does not typically have
the authority to set standards based on end use
(aside from school buses). Even if it had such
authority, vehicle manufacturers could not predict,
in many instances, which vehicles were ultimately
going to be used for permit operations and thus
could not identify which vehicles were excluded.
Many vehicles used in permit operations are
standard trucks and trailers with no special fea-
tures. If the agency were to attempt to exclude the
permit operation vehicles by excluding whole
vehicle types, the exclusion would be overbroad.
The agency notes that a variety of vehicle types
are used for these permit operations, and if
NHTSA were to exclude all of these types, it
would be excluding many vehicles not used for
permit operations. In addition, the professed rea-
son to exclude vehicles in permit operations (i.e.,
the presumed frequency of manual brake adjust-
ments) can be accomplished with brakes equipped
with automatic adjusters. Some truckers involved
in dangerous activities adjust their brakes every
day instead of relying on their automatic adjust-
ers, because automatic adjusters are equipped with
external adjusting mechanisms similar to the man-
ual adjusters. Therefore, if a permit hauler desires
to adjust its brakes manually, it can do so. Based
on the above, the agency believes that heavy
haulers involved in permit operations should be
required to comply with the automatic adjustment
requirements.

International Transquip recommended a salt
spray test and a stroke cycle test for accuracy.

performance, and readability. NHTSA notes that
these tests were not proposed in the NPRM and
does not believe they are necessary at this time.
The agency believes that a safety need for these
additional requirements could not be established.
In addition, the existing SAE Recommended Prac-
tice on automatic adjusters already requires
environmental chamber tests along with cycle
testing. If additional information indicated that
these tests would provide significant safety bene-
fits at reasonable costs, the agency would con-
sider proposing them.

MGM Brakes commented that the SAE Truck
and Bus Brake Actuator Sub-Committee has writ-
ten and approved a recommended practice for
cam or disc brake actuators. However, the SAE
has withheld this document from publication
because its policy is to not publish any rec-
ommended practice that will require another
manufacturer to infringe a patent. Apparently, one
air brake actuator manufacturer was recently
issued a patent on a stroke indicator marking sys-
tem. Notwithstanding the SAE's concern about
patent infringement, NHTSA notes that this rule
specifies a general performance standard. There-
fore, the agency does not anticipate that restric-
tions caused by patents will be a problem because
there are many different indicator designs and air
chamber push rods may be marked in many ways.

HydrauUcally-Braked Systems

1 . Brake Adjusters

The NPRM discussed the need for automatic
brake adjusters on hydraulically-braked vehicles,
including passenger cars. The notice explained
that all new passenger cars have been manufac-
tured with automatic adjusters for several years.
The agency stated that such a requirement would
be consistent with the agency's proposal in Stand-
ard No. 135 about international brake harmoni-
zation (52 PR 1474, January 14, 1987, 56 PR
30528, July 3, 1991). The proposal requested
comments on whether passenger cars should be
covered by this amendment to Standard No. 105.
The proposal also requested comment about
whether other hydraulically-braked vehicles
should be required to have automatic brake
adjusters.

No commenter expressly supported equipping
passenger cars and other hydraulic braked
vehicles with automatic brake adjusters. However,
several commenters, including General Motors

PART 571; SI 05— PRE- 120

and the Motor Vehicle Manufacturers Association
(MVMA), implicitly supported this requirement
by commenting that an immediate effective date
for such vehicles was feasible, provided that the
requirements did not require the development of
new designs. Chrysler and Toyota questioned the
need for such a requirement, claiming that
hydraulically-braked vehicles are already
equipped with such devices.

In addition, Ford and GM commented that, in
the interests of international brake harmonization,
the requirements about brake adjusters in Stand-
ard No. 105 and 135 should be identical. This
consideration led Ford to state that the proposal
in Standard No. 10105 about automatic correction
for over-adjustment was not needed.

After reviewing these comments. NHTSA has
determined that Standard No. 105 should be
amended to require automatic brake adjusters.
Because vehicles subject to Standard No. 105
typically are equipped with these devices, the
agency does not anticipate that the requirement
would pose a burden on manufacturers. In addi-
tion, amending Standard No. 105 to require these
devices will result in consistency between that
Standard and Standard No. 135. The agency notes
that such consistency is important because under
the Standard No. 135 proposal, a manufacturer
could comply with either standard during the five-
year phase-in period for Standard No. 135.

2. Adjustment Indicators

The NPRM stated that even though brake
adjusters would be required on hydraulically-
braked vehicles, automatic adjustment indicators
would not be required on these vehicles. The
notice explained that the agency believed that
there were no significant problems with automatic
brake adjusters for hydraulically-braked vehicles
or with checking the adjustment of the brakes on
such vehicles. Nevertheless, the agency requested
comments about whether adjustment indicators
should be required on hydraulically-braked
vehicles.

Chrysler believed that allowing continued vol-
untary compliance would be more appropriate
than mandating installation through rulemaking.
GM and MVMA stated that indicators should not
be required on hydraulic brakes because no safety
need for such a requirement has been dem-
onstrated.

NHTSA continues to believe that there is no
significant safety problem with automatic adjust-

ers for hydraulically-braked vehicles or with
checking the adjustment of such vehicles. Accord-
ingly, the agency has decided not to require
adjustment indicators on hydraulically-braked
vehicles.

Effective Date

The NPRM proposed that the amendments
become effective two years after promulgation of
the final rule. The agency proposed the same
leadtime for both air-braked and hydraulically-
braked vehicles.

With respect to automatic brake adjusters on
air-braked vehicles, the notice explained that most
truck and bus manufacturers already offer auto-
matic brake adjusters as standard equipment. The
agency acknowledged that most truck trailer
manufacturers do not offer automatic brake
adjusters as standard equipment; about 30 percent
of all new trailers are presently ordered with auto-
matic brake adjusters. In addition, the agency esti-
mated that about 60 percent of all new medium
and heavy trucks, buses, and trailers already have
automatic brake adjusters. NHTSA believed that a
switch from manual to automatic brake adjusters
would not require major redesigns of more than
a few, if any, vehicles because automatic brake
adjusters are already available for most vehicles
with manual adjusters and the overall brake sys-
tem is about the same size, with or without auto-
matic adjusters. The NPRM further stated that
manufacturers of automatic brake adjusters could
easily supply enough adjusters to equip all new
air-braked trucks, buses, and trailers within two
years.

The NPRM also stated that two years was
sufficient leadtime for the brake adjustment
indicator requirement, noting that two major air
brake manufacturers, with over 75 percent of the
market, already mark their push rods with a visual
indicator for under-adjustment. The notice stated
that other manufacturers should be able to
develop a brake adjustment indicator within two
years. The agency requested comments on the
adequacy of the leadtime generally and specifi-
cally for any particular types of vehicles or brake
systems which would require extensive redesign.
The notice explained that the agency would con-
sider providing longer leadtime for vehicles or
brake systems which needed additional leadtime.

Thirteen commenters addressed the proposed
leadtime for requiring brake adjusters and adjust-

PART571;S105— PRE-121

ment indicators on air-braked vehicles. The Inter-
national Brotherhood of Teamsters and a brake
consultant believed that a leadtime of one year or
less was appropriate, claiming that the equipment
is already available. Haldex stated that a one year
lead time would be possible provided that the
issue of adjustment indicators was separated. Sev-
eral commenters, including Ford, the National
School Transportation Association (NSTA), the
American Petroleum Institute, the Owner-Operator
Independent Drivers Association, TTMA, GM,
and MVMA believed that the proposed two year
leadtime was appropriate for requirements similar
to those being adopted in this final rule. Chrysler
believed that leadtime of three years would be
necessary for some manufacturers to develop
automatic adjusters and indicators.

NHTSA continues to believe that a two year
leadtime will provide manufacturers adequate
time to equip air-braked vehicles with brake
adjusters and adjustment indicators. The agency
notes that the final rule omits several provisions
that would have raised significant practicability
concerns for some vehicle and brake designs.
NHTSA further notes that although some manu-
facturers already comply or could quickly bring
their vehicles into compliance with the require-
ments, a significant number of small trailer manu-
facturers would have difficulty complying with
the amendments unless a two year leadtime is
provided.

As for hydraulically-braked vehicles, the notice
also proposed that the amendment become effec-
tive two years after publication of the final rule.
The NPRM requested comment on whether a
shorter leadtime for hydraulically-braked vehicles
was appropriate since these vehicles are typically
produced with automatic brake adjusters.

GM and MVMA stated that an immediate
effective date for hydraulically-braked vehicles
would be acceptable, provided that the amend-
ments did not require the development of new
designs. Ford stated that the two year time period
was more than adequate. No commenter requested
a leadtime for hydraulically-braked vehicles
longer than two years.

Based on the comments and available informa-
tion, NHTSA has determined that a one year lead-
time is appropriate for requiring automatic adjust-
ers on hydraulically-braked vehicles. Those com-
menters that addressed the issue indicated that an
immediate effective date would be acceptable. No

commenter stated that an effective date longer
than one year was necessary or that a one year
leadtime would pose an unreasonable burden.
Based on its review of hydraulically-braked
vehicles, NHTSA believes that all such passenger
cars and light trucks are equipped with an auto-
matic adjuster. As for hydraulically-braked
medium and heavy duty vehicles, the agency
notes that these vehicles are typically manufac-
tured by specialty manufacturers that purchase the
axle sets and brake components from major
manufacturers. The agency believes that the major
manufacturers or trade groups representing the
specialty manufacturers would have expressed
their concern if a shorter leadtime had posed a
hardship.

This final rule does not have any retroactive
effect. Under section 103(d) of the National Traf-
fic and Motor Vehicle Safety Act (15 U.S.C.
1392(d)), whenever a Federal motor vehicle safety
standard is in effect, a state may not adopt or
maintain a safety standard applicable to the same
aspect of performance which is not identical to
the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending or
revoking Federal motor vehicle safety standards.
That section does not require submission of a
petition for reconsideration or other administrative
proceedings before parties may file suit in court.

Part 571— [Amended]

In consideration of the foregoing, 49 CFR Part
571 is amended as follows:

1. The authority citation for Part 571 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403. 1407;
delegation of authority at 49 CFR 1 .50.

§571.105 [Amended]

2. S5.1 of §571.105 is amended by adding the
following after the current heading:

Each vehicle shall be equipped with a service
brake system acting on all wheels. Wear of the
service brake shall be compensated for by means
of a system of automatic adjustment.

§571.121 [Amended]

3. S5.1.8 of §571.121 is revised to read as fol-
lows:

PART 571: S105— PRE-122

S5.1.8 Brake distribution and automatic adjust-
ment. Each vehicle shall be equipped with a serv-
ice brake system acting on all wheels.

(a) Brake adjuster. Wear of the service brakes
shall be compensated for by means of a system
of automatic adjustment. The readjustment limits
shall be in accordance with those specified in
Appendix G to Subchapter B of Chapter III -
"Minimum Periodic Inspection Standards,"' 49
CFR Parts 200 to 399.

(b) Brake indicator. For each brake equipped
with an external automatic adjustment mechanism
and having an exposed pushrod, the condition of
service brake under-adjustment shall be displayed
by a brake adjustment indicator that is discernible
when viewed with 20/40 vision from a location
adjacent to or underneath the vehicle.

4. S5.2.2 of §571.121 is revised to read as fol-
lows:

S5.2.2 Brake distribution and automatic adjust-
ment. Each vehicle shall be equipped with a serv-
ice brake system acting on all wheels.

(a) Brake Adjuster. Wear of the service brakes
shall be compensated for by means of a system
of automatic adjustment. The readjustment limits
shall be in accordance with those specified in
Appendix G to Subchapter B of Chapter III —
"Minimum Periodic Inspection Standards," 49
CFR Parts 200 to 399.

(b) Brake Indicator. For each brake equipped
with an external automatic adjustment mechanism
and having an exposed pushrod, the condition of
service brake under-adjustment shall be displayed
by a brake adjustment indicator in a manner that
is discernible when viewed with 20/40 vision
from a location adjacent to or underneath the
vehicle.

Issued on October 14, 1992.

Marion C. Blakey
Administrator

57 F.R. 47793
October 20, 1992

PART 571; S105— PRE-123

MOTOR VEHICLE SAFETY STANDARD NO.
Hydraulic Brake Systems

105

51. Scope. This standard specifies requirements
for hydraulic service brake and associated parking
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 pas-
senger cars, multipurpose passenger vehilces,
trucks, and buses with hydraulic service brake sys-
tems.

54. Definitions. Antilock system means a portion
of a service brake system that automatically con-
trols the degree of rotational wheel slip at one or
more road wheels of the vehicle during braking.

Backup system means a portion of a service
brake system, such as a pump, that supplies
energy in the event of a primary brake power
source failure.

Brake power assist unit means a device
installed in a hydraulic brake system that reduces
the operator effort required to actuate the system,
and that if inoperative does not prevent the opera-
tor from braking the vehicle by a continued
application of muscular force on the service brake
control.

Brake power unit means a device installed in a
brake system that provides the energy required to
actuate the brakes, either directly or indirectly
therugh an auxiliary device, with the operator
action consisting only of modulating the energy
application level.

Hydraulic brake system means a system that
uses hydraulic fluid as a medium for transitting
force from a service brake control to the service
brake, and that may incorporate a brake power
assist unit, or a brake power unit.

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.

Lightly loaded vehicle weight means:

(a) for vehicles with a GVWR of 10,000
pounds or less, unloaded vehicle weight plus 500
pounds (including driver and instrumentation);

(b) for vehicles with a GVWR greater than
10,000 pounds, unloaded vehicle weight plus 500
pounds (including driver and instrumentation).

Parking mechanism means a component or sub-
system of the- drive train that locks the drive
train when the transmission control is placed in a
parking or other gear position and the ignition
key is removed.

Pressure component means a brake system
component that contains the brake system fluid
and controls or senses the fluid pressure.

Skid number means the frictional resistance of
a pavement measured in accordance with Amer-
ican Society for Testing and laterials (ASTM)
Method E-274-70 (as revised July, 1974) at 40
mph, omitting water delivery as specified in para-
graphs 7. 1 and 7.2 of that method.

Snub means the braking deceleration of a
vehicle from a higher reference speed to a lover
reference speed that is greater than zero.

Spike stop means a stop resulting from the
application of 200 pounds of force on the service
brake control in 0.08 second.

Split service brake system means a brake sys-
tem 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 two or more sub-sys-
tems) shall not impair the operation of any other
subsystem.

Stopping distance means the distance traveled
by a vehicle from the point of application of force
to the brake control to the point at which the
vehicle reaches a full stop.

Variable proportioning brake system means a
system that automatically adjusts the braking
force at the axles to compensate for vehicle static

PART 571; S 105-1

axle loading and/or dynamic weight transfer
between axles during deceleration.

S5. Requirements.

S5.1 Service brake systems. [Each vehicle
shall be equipped with a service brake system act-
ing on all wheels. Wear of the service brake shall
be compensated for by means of a system of auto-
matic adjustment. (57 F.R. 47793— October 20,
1992. Effective: October 20, 1993)]

S5.1.1 Stopping distance. The service brakes
shall be capable of stopping each vehicle, other
than a vehicle which both has a GVV/R of not less
than 8,000 pounds and not greater than 10,000
pounds and is not a school bus, in four effective-
ness tests within the distances and from thespeeds
specified in S5. 1.1.1, S5.1.1.2, S5.1.1.3, and
S5.1.1.4. The service brakes shall be capable of
stopping each vehicle which both has a GVWR of
not less than 8,000 pounds and not greater than
10,000 pounds and is not a school bus, in three
effectiveness tests within the distances and from
the speeds specified in S5. 1.1.1, S5.1.1.2, and
S5.1.1.4.

S.1.1.1 In the first (prebumished) effectiveness
test, the vehicle shall be capable of stopping from
30 mph and 60 mph within the corresponding dis-
tances specified in Column I of Table II.

S5.1.1.2 In the second effectiveness test, the
vehicle shall be capable of stopping from 30 and
60 mph within the corresponding distances speci-

fied in Column II of Table II. If the speed attain-
able in 2 miles is not less than 84 mph. a pas-
senger car or other vehicle with a GVWR of (
10,000 pounds or less shall also be capable of
stopping from 80 mph within the corresponding
distances specified in Column II of Table II.

55.1.1.3 In the third effectiveness test the vehicle
shall be capable of stopping at lightly loaded
vehicle weight from 60 mph within the cor-
responding distance specified in Column III of
Table II.

55.1.1.4 In the fourth effectiveness test, a vehicle
with a GVWR of 10,000 pounds or less shall be
capable of stopping from 30 and 60 mph within
the corresponding distances specified in Column I
of 7 Table II. If the speed attainable in 2 miles is
not less than 84 mph, a passenger-car lor other
vehicle with a GVWR of 10,000 lbs. or less shall
also be capable of stopping from 80 mph within
the corresponding distance specified in Column I
of Table II.

If the speed attainable in 2 miles is not less
than 99 mph, a passenger car shall, in addition,
be capable of stopping from the applicable speed
indicated below, within the corresponding dis-
tance specified in Column I of Table II.

Speed attainable in 2 miles (mph)

Required to stop
from (mph)

Not less than 99 but less than 104
104 or more

TABLE I— BRAKE TEST PROCEDURE SEQUENCE AND REQUIREMENTS

Sequ

Light

Test Procedure

Instrumentation check

First (prebumish) effectiveness test

Burnish procedure

Second effectiveness

First rebumish

Parking brake

Third effectiveness (lightly loaded vehicle)

Partial failure

Inoperative brake power and power assist ur

First fade and recovery

Second rebumish

Second fade and recovery

Third rebumish

Fourth effectiveness

Water recovery

Spike stops

Final inspection

Moving barrier test

S7.2

S7.3

S5. 1.1.1

S7.4

S7.5

S5.I.1.2

S7.6

S7.7

S5.2

S7.8

S5.1.1.3

S7.9

S5.1.2

S7.10

S5.1.3

S7.ll

S5.1.4

S7.12

—

S7.13

S.'i.l.4

S7.14

—

S7.15

S5.1.1.4

S7.16

S.S.L.'S

S7.17

S5.1.6

S7.18

S.5.6

S7.19

S5.2.2.3

(Rev. 10/20/92)

PART 571: S 105-2

S5.1.2 Partial failure.

55. 1.2.1 In vehicles manufactured with a spHt
service brake system, in the event of a rupture or
leakage type of failure in a single subsystem, other
than a structural failure of a housing that is com-
mon to two or more subsystems, the remaining
portion(s) of the service brake system shall con-
tinue to operate and shall be capable of stopping
a vehicle from 60 mph within the corresponding
distance specified in Column IV of Table II.

55.1.2.2 In vehicles not manufactured with a split
service brake system, in the event of any one rup-
ture or leakage type of failure in any component
of the service brake system the vehicle shall by
operation of the service brake control, be capable
of stopping 10 times consecutively from 60 mph
within the corresponding distance specified in
Column IV of Table II.

[S5.1.3 Inoperative brake power assist unit or
brake power unit. A vehicle equipped with one
or more brake power assist units shall meet the
requirements of either S5. 1.3.1, S5. 1.3.2, or
S5. 1.3.4 (chosen at the option of the manufac-
turer), and a vehicle equipped with one or more
brake power units shall meet the requirements of
either S5. 1.3.1, S5. 1.3.3, or S5. 1.3.4 (chosen at the

option of the manufacturer). (46 F.R. 55 — January
2, 1981. Effective: 9/1/83)]

55.1.3.1 The service brakes on a vehicle equipped
with one or more brake power assist units or brake
power units, with one such unit inoperative and
depleted of all reserve capability, shall be capable
of stopping a vehicle from 60 mph within the cor-
responding distance specified in Column IV of
Table II.

55.1.3.2 Brake power assist units. The service
brakes on a vehicle equipped with one or more
brake power assist units, with one such unit inop-
erative, shall be capable of stopping a vehicle
from 60 mph —

(a) In six consecutive stops at an average
deceleration for each stop that is not lower than
that specified in Column I of Table UI, when the
inoperative unit is not initially depleted of all
reserve capability; and

[(b) In a final stop, at an average deceleration
that is not lower than 7 fpsps for passenger cars
(equivalent stopping distance 554 feet) or 6 fpsps
for vehicles other than passenger cars (equivalent
stopping distance 646 feet), as applicable, when
the inoperative unit is depleted of all reserve
capacity. (46 F.R. 55— January 2, 1981. Effective:
9/1/83)]

[TABLE II— STOPPING DISTANCES

STOPPING DISTANCE IN FEET FOR TESTS INDICATED

III

Vehicle test

speed (miles

per hour)

1st (prebumish) power and 4th ef-
fectiveness: spike effectiveness
check

2d
effectiveness

3d (lightly loaded vehicle)
effectiveness

Inoperative brake
power and power as-
sist unit: partial failure

(a) (b) (c) (d)

(b)
(a) and (d)

(a) (b) (c) (d)

(b)

(a) and (d)

(c)

30 '57 '65 '-69(lst) '88 '54 '57 '81 51 57 65 81 114 130 170

'2 65 (4th

and
spike)

'72

35 74 83 91 132 70 74 132 67 74 83 132 155 176 225

40 96 108 119 173 91 96 173 87 96 108 173 202 229 288

45 121 137 150 218 115 121 218 110 121 137 218 257 291 358

50 150 169 185 264 142 150 264 135 150 169 264 317 359 435

55 181 204 224 326 172 181 326 163 181 204 326 383 433 530

60 '216 '242 '267 '388 '204 '216 '388 '194 '216 '242 '388 '456 '517 '613

80 '405 '459 '510 NA '383 NA NA NA NA NA NA NA NA NA

95 1607 NA NA NA NA NA NA NA NA NA NA NA NA NA

100 '673 NA NA NA NA NA NA NA NA NA NA NA NA NA

' Distances for specified tests. -Applicable to school buses only. NA=Not applicable.

Note — (a) passenger cars: (b) vehicles other than passenger cars with GVWR of less than 8.000 lbs: (c) vehicles with GVWR of not less

than 8,000 lbs. and not more than 10,000 lbs.; (d) vehicles with GVWR greater than 10.000 lbs. (46 F.R. 55— January 2, 1981. Effective: 9/
1/83)1

PART 571; S 105-3

[TABLE III— INOPERATIVE BRAKE POWER ASSIST AND BRAKE POWER UNITS

Stop No.

Average Deceleration, FPSPS

Equivalent Stopping Distance, Feet

Column 1-

-brake

power

Column 2-

-brake

power

Column 3-

-brake

power

Column 4— brake

assist

init

iSlSt

power

uni

(a)

(b) and (c)

(a)

(b)and(c)

(a)

(b) and (c)

(a)

(b)

and (c)

16.0

14.0

16.0

13.0

242

277

242

298

12.0

13.0

11.0

323

298

352

10.0

12.0

10.0

388

323

388

9.0

8.5

II.O

9.5

431

456

352

409

8.0

7.5

10.0

9.0

484

517

388

431

7.5

6.7

9.5

8.5

517

580

409

456

'7.0

'6.0

9.0

8.0

554

646

431

484

8.5

7.5

456

517

8.0

7.0

484

554

7.5

6.5

517

596

'7.0

'6.0

554

646

' Depleted, (a) passenger cars; (b) vehicles other than passenger cars with GVWR of 10,000 lbs. or less; (c) vehicles with GVWR greater
than 10,000 lbs.; NA=Not Applicable. (46 F.R. 55— January 29, 1981. Effective: 9/1/83)]

55.1.3.3 Brake power units. The service brakes
of a vehicle equipped with one or more brake
power units with an accumulator-type reserve sys-
tem, with any one failure in any one unit, shall be
capable of stopping the vehicle from 60 mph:

(a) In 10 consecutive stops at an average decel-
eration for each stop that is not lower than that
specified in Column II of Table III, when the unit
is not initially depleted of all reserve capability;
and

55.1.3.4 Brake power assist and brake power
units. The service brake of a vehicle equipped
with one or more brake power assist units or brake
power units with a backup system, with one brake
power assist unit or brake power unit inoperative
and depleted of all reserve capability and with
only the backup system operating in the failed
subsystem, shall be capable of stopping the
vehicle from 60 mph in 15 consecutive stops at an
average deceleration for each stop that is not
lower than 12 fpsps (equivalent stopping distance
323 feet).

S5.1.4 Fade and recovery. The service brakes
shall be capable of stopping each vehicle in two
fade and recovery tests as specified below.

55.1.4.1 The control force used for the base line
check stops or snubs shall be not less than 10
pounds, nor more than 60 pounds, except that the
control force for a vehicle with a GVWR of
10,000 pounds or more may be between 10
pounds and 90 pounds.

55.1.4.2 (a) Each vehicle with GVWR of 10,000
pounds or less shall be capable of making five
fade stops (10 fade stops on the second test) from
60 mph at a deceleration not lower than 15 fpsps
for each stop, followed by five fade stops at the
maximum decleration attainable from 5 to 15
fpsps.

(b) Each vehicle with a GVWR greater than
10,000 pounds shall be capable of making 10 fade
snubs (20 fade snubs on the second test) from 40
mph to 20 mph at 10 fpsps for each snub.

55.1.4.3 (a) Each vehicle with a GVWR of 10,000
pounds or less shall be capable of making five
recovery stops from 30 mph at ten fpsps for each
stop, with a control force application that falls
within the following maximum and minimum lim-
its:

(1) A maximum for the first four recovery
stops of 150 pounds, and for the fifth stop, of 20
pounds more than the average control force for
the baseline check; and

(2) A minimum of—

(A) The average control force for the base-
line check minus 10 pounds, or

(B) The average control force for the base-
line check times 0.60,

whichever result is lower (but in no case lower
than 5 pounds).

(Rev. 1/2/81)

PART 571; S 105-^

(b) Each vehicle with a GVWR of more than
10,000 pounds shall be capable of making five
recovery snubs from 40 mph to 20 mph at 10
fpsps of each snub, with a control force applica-
tion that falls within the following maximum and
minimum limits:

(1) A maximum for the first four recovery
snubs of 150 pounds, and for the fifth snub, of 20
pounds more than the average control force for
the baseline check (but in no case more than 100
pounds); and

(2) A minimum of —

(A) The average control force for the base-
line check minus 10 pounds, or

(B) The average control force for the base-
line check times 0.60, whichever is lower (but
in no case lower than 5 pounds).

S5.1.5 Water recovery. The service brakes shall
be capable of stopping each vehicle in a water
recovery test, as specified below.

55.1.5.1 The control force used for the baseline
check stops or snubs shall be not less than 10
pounds, nor more than 60 pounds, except that the
control force for a vehicle with a GVWR of
10,000 pounds or more may be between 10 and 90
pounds.

55. 1.5.2 (a) After being driven for 2 minutes at a
speed of 5 mph in any combination of forward
and reverse directions through a trough having a
water depth of 6 inches, each vehicle with a
GVWR of 10,000 pounds or less shall be capable
of making five recovery stops from 30 mph at 10
fpsps for each stop with a control force application
that falls within the following maximum and mini-
mum limits:

(1) A maximum for the first four recovery
stops of 150 pounds, and for the fifth stop, of 45
pounds more than the average control force for
the baseline check (but in no case more than 90
pounds, except that the maximum control force
for the fifth stop in the case of a vehicle manufac-
tured before September 1, 1976, shall be not more
than plus 60 pounds of the average control force
for the baseline check) (but in no case more than
110 pounds).

(2) A minimum of —

(A) The average control force for the base-
line check minus 10 pounds, or

(B) The average control force for the base-
line check times 0.60.
whichever result is lower (but in no case lower
than 5 pounds).

(b) After being driven for 2 minutes at a speed
of 5 mph in any combination of forward and
reverse directions through a trough having a water
depth o 6 inches, each vehicle with a GVWR of
more than 10,000 pounds shall be capable of
making five recovery snubs from 40 mph to 20
mph at 10 fpsps for each snub, with a control
force application that falls within the following
maximum and minimum limits:

(1) A maximum for the first four recovery
stops of 150 pounds, and for the fifth stop, of 60
pounds more than the average control force for
the baseline check (but in no case more than 110
pounds); and

(2) A minimum of —

(A) The average control force for the base-
line check minus 10 pounds, or

(B) The average control force for the base-
line check times 0.60, whichever is lower (but
in no case lower than 5 pounds).

S5.1.6 Spike stops. Each vehicle with a GVWR
of 10,000 lbs. or less shall be capable of making
10 spike stops from 30 mph, followed by
effectiveness (check) stops from 60 mph, at least
one of which shall be within a corresponding stop-
ping distance specified in Column I of Table II.

S5.2 Parking brake system. Each vehicle [with
a GVWR of 10,000 lbs. or less and each school
bus with a GVWR greater than 10,000 lbs.] shall
be manufactured with a parking brake system of
a friction type with a solely mechanical means to
retain engagement, which shall under the condi-
tions of S6, when tested according to the proce-
dures specified in S7, meet the requirements
specified in S5.2.1, S5.2.2, or S5.2.3 as appro-
priate, with the system engaged —

(a) In the case of a [vehicle with a GVWR of
10,000 lbs. or less] with a force applied to the
control not to exceed 125 pounds for a foot-oper-
ated system and 90 pounds for a hand-operated
system; and

(b) In the case of a school bus [with a GVWR
greater than 10,000 lbs.] with a force applied to
the control not to exceed 150 pounds for a foot-
operated system and 125 pounds for a hand-oper-

PART571; S 105-5

(Rev. 12/21/81)

ated system. (46 F.R. 61887— December 21, 1981.
Effective: 9/1/83)

55.2.1 Except as provided in S5.2.2, the parking
brake system on a [passenger car and on a school
bus] with a GVWR of 10.000 pounds or less shall
be capable of holding the vehicle stationary (to the
hmit of traction on the braked wheels) for 5 min-
utes in both a forward and reverse direction on a
30 percent grade. (46 F.R. 61887— December 21,
1981. Effective: 9/1/83)

55.2.2 A vehicle of a type described in S5.2.1 at
the option of the manufacturer may meet the
requirements of S5.2.2.I, S5.2.2.2, and S5.2.2.3
instead of the requirements of S5.2.1 if:

(a) The vehicle has a transmission or trans-
mission control which incorporates a parking
mechanism, and

(b) The parking mechanism must be engaged
before the ignition key can be removed.

55.2.2.1 The vehicle's parking brake and parking
mechanism, when both are engaged, shall be
cpable of holding the vehicle stationary (to the
limit of traction of the braked wheels) for 5 min-
utes, in both forward and reverse directions, on a
30 percent grade.

55.2.2.2 The vehicle's parking brake, with the
parking mechanism not engaged, shall be capable
of holding the vehicle stationary for 5 minutes, in
both forward and reverse directions, on a 20 per-
cent grade.

55.2.2.3 With the parking mechanism engaged
and the parking brake not engaged, the parking
mechanism shall not disengage or fracture in a
manner permitting vehicle movement, when the
vehicle is impacted at each end, on a level surface,
by a barrier moving at IVi mph.

55.2.3 The parking brake system on a multipur-
pose passenger vehicle, truck, and bus (other than
a school bus) with a GVWR greater than 10,000
pounds shall be capable of holding the vehicle
stationary for 5 minutes, in both forward and
reverse directions, on a 20 percent grade.

S5.3 Brake system Indicator lamp. Each
vehicle shall have one or more brake system
indicator lamps, mounted in front of and in clear
view of the driver, which meet the requirements of

S5.3.1 through S5.3.5. However, the options pro-
vided in S5.3.1(a) shall not apply to a vehicle
manufactured without a split service brake system:
such a vehicle shall, to meet the requirements of
S5.3.1(a), be equipped with a warning indicator
that activates under the conditions specified in
S5. 3. 1(a)(4). This warning indicator shall, instead
of meeting the requirements of S5.3.2 through
S5.3.5, activate (while the vehicle remains capable
of meeting the requirements of S5. 1.2.2 and the
ignition switch is in the "on" position) a continu-
ous or intermittent audible signal and a flashing
warning light displaying the words "STOP —
BRAKE FAILURE" in block capital letters not
less than one-quarter of an inch in height.

55.3.1 An indicator lamp shall be activated when
the ignition (start) switch is in the "on" ("run")
position and whenever any of conditions (a), (c),
or (d) occur, or, at the option of the manufacturer,
whenever any of conditions (b), (c), or (d) occur:

(a) A gross loss of pressure (such as caused by
rupture of a brake line but not by a structural fail-
ure of a housing that is common to two or more
subsystems) due to one of the following condi-
tions (chosen at the option of the manufacturer):

(1) Before or upon application of a differen-
tial pressure of not more than 225 lb/in-
between the active and failed brake system
measured at a master cylinder outlet or a slave
cylinder outlet.

(2) Before or upon application of 50 pounds
of control force upon a fully manual service
brake.

(3) Before or upon application of 25 pounds
of control force upon a service brake with a
brake power assist unit.

(4) When the supply pressure in a brake
power unit drops to a level not less than one-
half of the noiTnal system pressure.

(b) A drop in the level of brake fluid in any
master cylinder reservoir compartment to less
than the recommended safe level specified by the
manufacturer or to one-fourth of the fluid capac-
ity of the reservoir compartment, whichever is
greater.

(d) Application of the parking brake.

55.3.2 [(a) Except as provided in paragraph (b) of
this section, all indicator lamps shall be activated

(Rev. 12/21/81)

PART 571; S 105-6

as a check of lamp function either when the igni-
tion (start) switch is turned to the "on" (run)
position when the engine is not running, or when
the ignition (start) switch is in a position between
"on" (run) and "start" that is designated by the
manufacturer as a check position.

(b) The indicator lamps need not be activated
when a starter interlock is in operation. (54 F.R.
40080— September 29, 1989. Effective: September
1, 1991)]

55.3.3 Each indicator lamp activated due to a
condition specified in S5.3.1 shall remain acti-
vated as long as the condition exists, whenever the
ignition (start) switch is in the "on" ("run")
position, whether or not the engine is running.

55.3.4 When an indicator lamp is activated it may
be steady burning or flashing.

S5.3.5(a) (a) Each indicator lamp shall display
word, words, or abbreviation, in accordance with
the requirements of Standard No. 101 (49 CFR
571.101) and/or this section, which shall have let-
ters not less than '/s-inch high and be legible to
the driver in daylight when lighted.

(b) If a single common indicator is used, the
lamp shall display the word "Brake". The letters
and background of a single common indicator
shall be of contrasting colors, one of which is red.

(c)(1) I separate indicator lamps are used for
one or more than one of the functions described
in S5.3.1(a) through S5.3.1(d), the display shall,
except as provided in (c)(1) (A) through (D) of
this section, include the word "Brake" and
appropriate aditional labeling.

(A) If a separate indicator lamp is provided for
gross loss of pressure, the words "Brake Pres-
sure" shall be used for S5.3.1(a).

(B) If a separate indicator lamp is provided for
low brake fluid, the words "Brake Fluid" shall
be used for S5.3.1(b), except for vehicles using
hydraulic system mineral oil.

(C) If a separate indicator lamp is provided for
an anti-lock system, the single word "Antilock"
or "Anti-lock" may be used for S5.3.1(c).

(D) If a separate indicator lamp is provided for
application of the parking brake, the single word
"Park" may be used for S5.3.1(d).

(2) Except for a separate indicator lamp for an
anti-lock system, the letters and background of
each separate indicator lamp shall be of contrast-
ing colors, one of which is red. The letters and

background of a separate indicator lamp for an
anti-lock system shall be of contrasting colors,
one of which is yellow.

S5.4 Reservoirs.

55.4.1 Master cylinder reservoirs. A master
cylinder shall have a reservoir compartment for
each service brake subsystem serviced by the mas-
ter cylinder. Loss of fluid from one compartment
shall not result in a complete loss of brake fluid
from another compartment.

55.4.2 Reservoir capacity. Reservoirs, whether
for master cylinders or other type systems, shall
have a total minimum capacity equivalent to the
fluid displacement resulting when all the wheel
cylinders or caliper pistons serviced by the res-
ervoirs move from a new lining, fully retracted
position (as adjusted initially to the manufacturer's
recommended setting) to a fully worn, fully
applied position, as determined in accordance with
S7. 18(c) of this standard. Reservoirs shall have
completely separate compartments for each sub:
system except that in reservoir systems utilizing a
portion of the reservoir for a common supply to
two or more subsystems, individual partial
compartments shall each have a minimum volume
of fluid equal to at least the volume displaced by
the master cylinder piston servicing the subsystem,
during a full stroke of the piston. Each brake
power unit reservoir servicing only the brake sys-
tem shall have a minimum capacity equivalent to
the fluid displacement required to charge the sys-
tem piston(s) or accumulator(s) to normal operat-
ing pressure plus the displacement resulting when
all the wheel cylinders or caliper pistons serviced
by the reservoir or accumulator(s) move from a
new lining fully retracted position (as adjusted ini-
tially to the manufacturer's recommended setting)
to a fully worn, fully applied position.

55.4.3 Reservoir labeling. Each vehicle shall
have a brake fluid warning statement that reads as
follows, in letters at least Vs 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
embossed;

PART 571; S 105-7

(Rev. 9/29/89)

(b) Located so as to be visible by direct view,
either on or within 4 inches of the braice fluid res-
ervoir filler plug or cap; and

55.5 Antilock and variable proportioning
bral<e systems. In the event of failure (structural
or functional) in an antilock or variable propor-
tioning brake system the vehicle shall be capable
of meeting the stopping distance requirements
specified in S5.1.2 for service brake system partial
failure.

55.6 Brake system Integrity. Each vehicle shall
be capable of completing all performance require-
ments of S5 without —

(a) Detachment or fracture of any component
of the braking system, such as brake springs and
brake shoe or disc pad facing, other than minor
cracks that do not impair attachment of the fric-
tion facing. All mechanical components of the
braking system shall be intact and functional.
Friction facing tearout (complete detachment of
lining) shall not exceed 10 percent of the lining
on any single frictional element.

(b) Any visible brake fluid or lubricant on the
friction surface of the brake, or leakage at the
master cylinder or brake power unit reservoir
cover, seal, and filler openings.

S6. Test conditions. The performance require-
ments of S5 shall be met under the following
conditions. Where a range of conditions is speci-
fied, the vehicle shall be capable of meeting the
requirements at all points within the range.

S6.1 Vehicle weight.

S6.1.1 Other than tests specified at lightly loaded
vehicle weight in S7.7, S7.8, and S7.9, the vehicle
is loaded to its GVWR such that the weight on
each axle as measured at the tireground interface
is in proportion to its GAWR, except that [each]
fuel tank is filled to any level from 100 percent
of capacity (corresponding to full GVWR loading)
to 75 percent. (46 F.R. 55— January 2, 1981. Effec-
tive: 9/1/83)

However, if the weight on any axle of a vehicle
at lightly loaded vehicle weight exceeds the axle's
proportional share of the gross vehicle weight rat-
ing, the load required to reach GVWR is placed

so that the weight on that axle remains the same
as at lightly loaded vehicle weight.

S6.1.2 For the applicable tests specified in S7.7,
S7.8, and S7.9, vehicle weight is lightly loaded
vehicle weight, with the added weight distributed
in the front passenger seat area in passenger cars
[multipurpose vehicles and trucks] and in the
area adjacent to the driver's seat in buses. (46 F.R.
55— January 2, 1981. Effective: 9/1/83)

56.2 Test loads. [Reserved.]

56.3 Tire Inflation pressure. Tire inflation pres-
sure is the pressure recommended by the vehicle
manufacturer for the GVWR of the vehicle.

56.4 Transmission selector control. For S7.3,
S7.5, S7.8, S7.15, S7.17, S7.ll. 1.2. S7. 11.2.2,
S7.11.3.2, and as required for S7.13, the trans-
mission selector control is in neutral for all decel-
erations. For all other tests during all decelera-
tions, the transmission selector is in the control
position, other than overdrive, recommended by
the manufacturer for driving on a level surface at
the applicable test speed. To avoid engine stall
during tests required to be run in gear a manual
transmission may be shifted to neutral (or the
clutch disengaged) when the vehicle speed
decreases to 20 mph.

56.5 Engine. Engine idle speed and ignition tim-
ing settings are according to the manufacturer's
recommendations. If the vehicle is equipped with
an adjustable engine speed governor, it is adjusted
according to the manufacturer's recommendation.

56.6 Vehicle Openings. All vehicle openings
(doors, windows, hood, trunk, convertible top,
cargo doors, etc.) are closed except as required for
instrumentation purposes.

56.7 Ambient temperature. The ambient
temperature is any temperature between 32° F.
and 100° F.

56.8 Wind velocity. The wind velocity is zero.

56.9 Road surface. Road tests are conducted on
a 12-foot-wide, level roadway having a skid num-
ber of 8 1 . Burnish stops are conducted on any sur-
face. The parking brake test surface is clean, dry
smooth Portland cement concrete.

(Rev. 1/2/81)

PART 571; S 105-

S6.10 Vehicle position. The vehicle is ahgned
in the center of the roadway at the start of each
brake appHcation. Stops, other than spiiie stops,
are made without any part of the vehicle leaving
the roadway. Except as noted below, stops are
made without lockup of any wheel at speeds
greater than 10 mph. There may be controlled
lockup on an antilock-equipped axle, and lockup
of not more than one wheel per vehicle, uncon-
trolled by an antilock system. [Dual wheels on
one side of an axle are considered a single
wheel.] Locked wheels at speeds greater than 10
mph are allowed during spike stops (but not spike
check stops), partial failure stops, and inoperative
brake power or power assist unit stops. (46 F.R.
55)— January 2, 1981. Effective: 9/1/83)

S6.11 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. A second
thermocouple may be installed at the beginning of
the test sequence if the lining wear is expected to
reach a point causing the first thermocouple to
contact the metal rubbing surface of a drum or
rotor. For center-grooved shoes or pads,
thermocouples are installed within one-eighth of
an inch to one-quarter inch of the groove and as
close to the center as possible.

CO DRILL NO. 31
0.100 MAX DEPTH
BEFORE GRIND

Figure 1 — Typical Plug Thermocuple Installations

PART 571; S 105-9

(Rev. 1/2/81)

S6.12 Initial brake temperature. Unless other-
wise specified, the brake temperature is 150° F to
200° F.

equipped with a headlighting ststem designed to
conform to the requirements of S7.3, S7.4, S7.5,
or S7.6.

S6.13 Control forces. Unless otherwise speci-
fied, the force applied to a brake control is not
less than 15 pounds and not more than 150
pounds.

S7. Test procedures and sequence. [Each
vehicle shall be capable of meeting all the
applicable requirements of S5 when testing
according 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 pennitted in burnish and
rebumish procedures and in S7.9 and S7.10. (For
vehicles only having to meet the requirements of
S5.1.2 and S5.1.3 in section S5.1, the applicable
test procedures and sequence are S7.1, S7.2, S7.4,
S7.9, S7.10, and S7.18. However, at the option of
the manufacturer, the following test procedures
and sequence may be conducted: S7.1, S7.2, S7.3,
S7.4, S7.5, S7.6, S7.7, S7.8, S7.9, S7.10 and
S7.18. The choice of this option shall not be con-
strued as adding to the requirements specified in
S5.1.2 and S5.1.3.) For vehicles manufactured
before September 1, 1991, automatic adjusters
may be locked out, at the option of the manufac-
turer, when the vehicle is prepared for testing. If
this option is selected, adjusters must remain
locked out for the entire sequence of tests. For
vehicles manufactured on or after September 1,
1991, automatic adjusters must remain activated at
all times. A vehicle shall be deemed to comply
with the stopping distance requirements of 55. 1 if
all least one of the stops at each speed and load
specified in each of S7.3, S7.5, S7.8, S7.9, S7.10,
S7.15, or S7.17 (check stops) is made within a
stopping distance that does not exceed the cor-
responding distance specified in Table II. When
the transmission selector control is required to be
in neutral for a deceleration, a stop or snub shall
be obtained by the following procedures: (1)
Exceed the test speed by 4 to 8 mph; (2) close the
throttle and coast in gear to approximately 2 mph
above the test speed; (3) Shift to neutral; and (4)
when the test speed is reached apply the service
brakes. (54 F.R. 40080— September 29, 1989. Effec-
tive: September 1, 1991)]

S7.1 Brake warming. Each passenger car, multi-
purpose passenger vehicle, truck and bus shall be

57.2 Pretest Instrumentation cfieck. Conduct a
general check of instrumentation by making not
more than 10 stops from a speed of not more than
30 mph, or 10 snubs from a speed of not more
than 40 mph to 10 mph, at a deceleration of not
more than 10 fpsps. If instrument repair, replace-
ment, or adjustment is necessary, make not more
than 10 additional stops or snubs after such repair,
replacement, or adjustment.

57.3 Service brake system — first (reburnish)
effectiveness test. Make six stops from 30 mph.
Then make six stops from 60 mph.

57.4 Service brake system— burnish proce-
dure.

57.4.1 Vehicles with GVWR of 10,000 pounds
or less.

57.4.1.1 Burnish. Burnish the brakes by making
200 stops from 40 mph at 12 fpsps (the 150 pound
control force limit does not apply here). The inter- ^'
val from the start of one service brake application (^
to the start of the next shall be either the time nec-
essary to reduce the initial brake temperature to
between 230° F and 270° F, or the distance of 1

mile, whichever occurs first. Accelerate to 40 mph
after each stop and maintain that speed until mak-
ing the next stop.

57.4.1.2 Brake adjustment— post burnish.

[After burnishing, adjust the brakes in accordance
with the manufacturer's published recommenda-
tions. 54 F.R. 40080— September 29, 1989.
Effective: September I, 1991.)]

57.4.2 Vehicles with GVWR greater than
10,000 pounds.

S7.4.2.1 Burnish. Vehicles manufactured before
September 1, 1993 may be burnished according to
the procedures set forth in S 7.4.2. 1(a) or
S 7.4.2.1(b) of this section, at the manufactures
option. Vehicles manufactured on or after Septem-
ber 1, 1993 shall be burnished according to the
procedures set forth in S 7.4.2. 1(b) of this section. ^
(a) Burnish the brakes by making 500 snubs at \^
10 fsps in the sequence specified in Table IV and

PART 571; S 105-10

within the speed ranges indicated. Except where
an adjustment is specified, after each braice
appHcation accelerate to the next speed specified
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 any speed specified in 1
mile, continue to accelerate until the speed speci-
fied is reached or until the vehicle has traveled
1.5 miles from the initial point of the previous
brake application, whichever occurs first. If dur-
ing any of the brake applications specified in
Table IV the hottest brake reaches 500° F, make
the remainder of the 500 applications from that
snub condition, except that a higher or lower snub
condition shall be followed (up to the 60 mph ini-
tial speed) as necesary to maintain a hottest brake
temperature of 500° F±50° F. However, if at a
snub condition of 40 to 20 mph, the temperature
of the hottest brake exceeds 550° F, make the
remainder of the 500 brake applications from that
snub condition, without regard to the brake
temperature. The brakes shall be adjusted three
times during the burnish procedure, in accordance
with the manufacturer's recommendations, after
125, 250, and 375 snubs.

Table IV

Snub condi-
tions (highesi
speed indi-
cated)

175 40 to 20 mph

25 45 to 20 mph

25 50 to 20 mph

25 55 to 20 mph

250 60 to 20 mph

(b) Burnish the brakes by making 500 snubs
between 40 mph and 20 mph at a deceleration
rate of 10 fsps. Except where an adjustment is
specified, after each brake application accelerate
to 40 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 the vehicle cannot attain a speed of 40 mph in
1 mile, continue to accelerate until the vehicle
reaches 40 mph or until the vehicle has traveled
1.5 miles from the initial point of the previous
brake application, whichever occurs first. The
brakes shall be adjusted three times during the

t burnish procedure, the accordance with the manu-
facturer's recommendations, after 125, 250, and

375 snubs.

S7.4.2.2 [Brake adjustment — post burnish. After
burnishing, adjust the brakes in accordance with
the manufacturer's published recommendations.
(54 F.R. 40080— September 29, 1989. Effective:
September 1, 1991)]

57.5 Service brake system— second effective-
ness test. Repeat S7.3. Then (for passenger cars)
and other vehicles with a GVWR of 10,000 lbs.
or less make four stops from 80 mph if the speed
attainable in 2 miles is not less than 84 mph.

57.6 First reburnish. Repeat S7.42 except make
35 burnish stops or snubs. In the case of vehicles
burnished in accordance with S7.4.2.1(a) of this
section, reburnish the vehicle by making 35 snubs
from 60 mph to 20 mph, but if the hottest brake
reaches 500° F±50° F make the remainder of the
brake applications from the highest snub condition
listed in Table IV that will maintain the hottest
brake temperature a 500° F±50° F. If at a snub
condition of 40 to 20 mph, the temperature of the
hottest brake exceeds 550° F, make the remainder
of the 35 brake applications from the snub condi-
tion without regard to brake temperature.

57.7 Parking brake test. The parking brake
tests for any vehicle on different grades, in dif-
ferent directions, and for different loads may be
conducted in any order. The force required for
actuation of a hand-operated brake system shall be
measured at the center of the hand grip area or at
a distance of I '/i inches from the end of the actu-
ation lever, as illustrated in Figure 2.

S7.7 Test procedure for requirements of
S5.2.1.

57.7.1.1 Condition the parking brake friction ele-
ments so that the temperature at the beginning of
the test is at any level not more than 150° F (when
the temperature of components on both ends of an
axle are averaged).

57.7.1.2 Drive the vehicle, loaded to GVWR, onto
the specified grade with the longitudinal axis of
the vehicle in the direction of the slope of the
grade, stop the vehicle and hold it stationary by
application of the service brake control, and place
the transmission in neutral.

PART 571; S 105-11

'"^^' »-^,. -if

LEVER TYPE A

F = APPLIED
R = REACTION

LEVER TYPE B

Figure 2 — Location for Measuring Brake Application Force (Hand Bral<e)

S7.7.1.3 With the vehicle held stationary by
means of the service brake control, apply the park-
ing brake by a single application of the force
specified in (a) or (b). except that a series of
applications to achieve the specified force may be
made in the case of a parking brake system design
that does not allow the application of the specified
force in a single application:

[(a) In the case of a passenger car or other
vehicle with a GVWR of 10,000 lbs. or less, not
more than 125 pounds for a foot-operated system,
and not more than 90 pounds for a hand-operated
system; and

(b) In the case of a school bus with a GVWR
greater than 10,000 lbs. not more than 150
pounds for a foot-operated system, and not more
than 125 pounds for a hand-operated system. (46
F.R. 55— January 2, 1981. Effective: 9/1/83)]

57.7.1 .5 Following observation of the vehicle in a
stationary condition for the specified time in one
direction, repeat the same test procedure with the
vehicle orientation in the opposite direction on the
specified grade.

57.7.1 .6 Check the operation of the parking brake
application indicator required by S5.3.1(d).

S7.7.2 Test procedures for requirements of
S5.2.2. (a) Check that transmission must be placed
in park position to release key;

(b) Test as in S7.7.1, except in addition place
the transmission control to engage the parking
mechanism; and

S7.7.1.4 Following the application of the parking
brake in accordance with S7.7.1.3, release all
force on the service brake control and commence
the measurement of time if the vehicle remains
stationary. If the vehicle does not remain station-
ary, reapplication of the service brake to hold the
vehicle stationary, with reapplication of a force to
the parking brake control at the level specified in
S7. 6. 1.3(a) or (b) as appropriate for the vehicle
being tested (without release of the ratcheting or
other holding mechanism of the parking brake)
may be used twice to attain a stationary position.

57.7.3 Lightly loaded vehicle. Repeat S7.7.1 or
S7.7.2 as applicable except with the vehicle at
lightly loaded vehicle weight.

57.7.4 Non-service brake type parking brake
systems. For vehicles with parking brake systems
not utilizing the service brake friction elements,
burnish the friction elements of such systems prior
to parking brake tests according to the manufac-
turer's published recommendations as furnished to
the purchaser. If no recommendations are fur-
nished, run the vehicle in an unbumished condi-

(Rev. 1/2/81)

PART 571; S 105-12

57.8 Service brake system-lightly loaded

• vehicle (third effectiveness) test. Make six stops
from 60 mph with vehicle at Hghtiy loaded vehicle
weight. [This test is not applicable to a vehicle
which both has a GVWR of not less than 8.000
pounds and not greater than 10,000 pounds and is
not a school bus. (46 F.R. 55— January 2, 1981.
EfTective: 9/1/83)]

57.9 Service brake system test-partial failure.

S7.9.1 With the vehicle at lightly loaded vehicle
weight, alter the service brake system to produce
any one rupture or leakage type of failure, other
than a structural failure of a housing that is com-
mon to two or more subsystems. Determine the
control force, pressure level, or fluid level (as
appropriate for the indicator being tested) nec-
essary to activate the brake system indicator lamp.
Make 4 stops if the vehicle is equipped with a
split service brake system, or 10 stops if the
vehicle is not so equipped, each from 60 mph, by
a continuous application of the service brake con-
trol. Restore the service brake system to nonnal at
^ completion of this test.

^ S7.9.2 Repeat S7.9.1 for each of the other sub-
systems.

57.9.3 Repeat 57.9.1 and 57.9.2 with vehicle at
GVWR. Restore the service brake system to nor-
mal at completion of this test.

57.9.4 (For vehicles with antilock and/or variable
proportioning brake systems.) With vehicle at
GVWR, disconnect functional power source, or
otherwise render antilock system inoperative. Dis-
connect variable proportioning brake system.
Make four stops, each from 60 mph. If more than
one antilock or variable proportioning brake sub-
system is provided, disconnect or render one sub-
system inoperative and run as above. Restore sys-
tem to normal at completion of this test. Repeat
for each subsystem provided. Determine whether
the brake system indicator lamp is activated when
the electrical power source to the antilock or vari-
able proportioning unit is disconnected.

^ S7.10 Service brake system — Inoperative
M brake power unit or brake power assist unit
^ test. (For vehicles equipped with brake power unit

or brake power assist unit.)

57.10.1 Regular procedure. (This test need not
be run if the option in S7.10.2 is selected.) On
vehicles with brake power assist units, render the
brake power assist unit inoperative, or one of the
brake power assist unit subsystems if two or more
subsystems are provided by disconnecting the rel-
evant power supply. Exhaust any residual brake
power reserve capability of the disconnected sys-
tem. On vehicles with brake power units, dis-
connect the primary source of power. Make four
stops, each from 60 mph, by a continuous applica-
tion of the service brake control. Restore the sys-
tem to normal at completion of this test. For
vehicles equipped with more than one brake
power unit or brake power assist unit, conduct
tests for each in turn.

57.10.2 Optional procedures— passenger cars
only. On vehicles with brake power assist units,
the unit is charged to maximum prior to start of
test. (Engine may be run up in speed, then throttle
closed quickly to attain maximum charge on
vacuum assist units.) Brake power units shall also
be charged to maximum accumulator pressure
prior to start of test. No recharging is allowed
after start of test.

(a) (For vehicles with brake power assist units.)
Disconnect the primary source of power. Make

six stops each from 60 mph, to achieve the aver-
age deceleration for each stop as specified in
Table III. Apply the brake control as quickly as
possible. Maintain control force until vehicle has
stopped.

At the completion of the stops specified above,
deplete the system of any residual brake power
reserve capability. Make one stop from 60 mph at
an average deceleration of not lower than 7 fpsps
for passenger cars (equivalent stopping distance
554 feet), or 6 fpsps for vehicles other than pas-
senger cars (equivalent stoppng distance 646 feet)
and determine whether the control force exceeds
150 pounds.

(b) (For vehicles with brake power units with
accumulator type systems.) Test as in S7. 10.2(a),
except make 10 stops instead of 6 and, at the
completion of the 10 stops, deplete the failed ele-
ment of the brake power unit of any residual
brake power reserve capability before making the
final stop.

(c) (For vehicles with brake power assist or
brake power units with backup systems.) If the
brake power or brake power assist unit operates

PART 571; S 105-13

(Rev. 1/2/81)

in conjunction with a backup system and the
backup system is activated automatically in the
event of a primal^ power failure, the backup sys-
tem is operative during this test. Disconnect the
primary source of power of one subsystem. Make
15 stops, each from 60 mph, with the backup sys-
tem activated for the failed subsystem, to achieve
an average deceleration of 12 fpsps for each stop,
(d) Restore systems to normal at completion of
these tests. For vehicles equipped with more than
one brake power assist or brake power unit, con-
duct tests of each in turn.

S7.11 Service brake system— first fade and
recovery test.

57.1 1 .1 Baseline check stops or snubs.

57.1 1.1.1 Vehicles with GVWR of 10,000
pounds or less. Make three stops from 30 mph
at 10 fpsps for each stop. Control force readings
ma be terminated when vehicle speed falls to 5
mph. Average the maximum brake control force
required for the three stops.

57.11.1.2 Vehicles with GVWR greater than
10,000 pounds. With transmission in neutral (or
declutched), make three snubs from 40 to 20 mph
at 10 fpsps for each snub. Average the maximum
brake control force required for the three snubs.

57.11.2 Fade stops or snubs.

S7.1 1.2.1 Vehicles with GVWR of 10,000
pounds or less. Make 5 stops from 60 mph at 15
fpsps followed by 5 stops at the maximum attain-
able deceleration between 5 and 1 5 fpsps for each
stop. Establish an initial brake temperature before
the first brake application of 130° F to 150° F. Ini-
tial brake temperatures before brake applications
for subsequent stops are those occurring at the dis-
tance intervals. Attain the required deceleration
within 1 second and, as a minimum, maintain it
for the remainder of the stopping time. Control
force readings may be terminated when vehicle
speed falls to 5 mph. Leave an interval of 0.4 mile
between the start of brake applications. Accelerate
immediately to the initial test speed after each
stop. Drive 1 mile at 30 mph after the last fade
stop, and immediately follow the recovery proce-
dure specified in S7. 11.3.1.

S7.1 1.2.2 Vehicles with GVWR greater than
10,000 pounds. With transmission in neutral (or
declutched), make 10 snubs from 40 to 20 mph at ^^
10 fpsps for each snub. Establish an initial brake ^
temperature before the first brake application of
130°F. to 150°F. Initial brake temperatures before
brake application for subsequent snubs are those
occurring in the time intei-vals specified below.
Attain the required deceleration within 1 s and
maintain it for the remainder of the snubbing time.
Leave an interval of 30 s between snubs (start of
brake application to start of brake application).
Accelerate immediately to the initial test speed
after each snub. Drive for .5mi at 40 mph after the
last snub and immediately follow the recovery
procedure specified in S7. 11.3.2.

S7.11.3 Recovery stops or snubs.

57.1 1.3.1 Vehicles with GVWR of 10,000 Ibor
less. Make five stops from 30 mph at 10 fpsps for
each stop. Control force readings may be termi-
nated when vehicle speed falls to 5 mph. Allow

a braking distance interval of 1 mi. Immediately
after each stop accelerate at maximum rate to 30
mph and maintain that speed until making the next
stop. Record the maximum control force for each ^^
stop.

57.1 1.3.2 Vehicles with GVWR greater than
10,000 lb. Witn transmission in neutural (or
declutched) make five snubs from 40 to 20 mph
at 10 fpsps for each snub. After each snub, accel-
erate at maximum rate to 40 mph and maintain
that speed until making the next brake application
at a point 1.5 mi form the point of the previous
brake application. Record the maximum control
force for each snub.

57.12 Service brake system— second
reburnish. Repeat S7.6.

57.13 Service brake system— second fade
and recovery test. Repeat S7.ll except in
S7.11.2 run 15 fade stops or 20 snubs instead of
10.

57.14 Third reburnish. Repeat S7.6.

57.15 Service brake system— fourth effective-
ness test. Repeat S7.5. Then (for passenger cars) ip.
make four stops from either 95 mph if the speed \
attainable in 2 miles is 99 to (but not including)

PART 571; S 105-14

104 mph, or 100 mph if the speed attainable in 2
miles is 104 mph or greater.

57.16 Service brake system— water recovery
test.

57.16.1 Baseline clieck stop. Make three stops
from 30 mph at 10 fpsps for each stop. Control
force readings may be terminated when vehicle
speed falls to 5 mph. Average the maximum brake
control force required for the three stops.

57.16.2 Wet brake recovery stops. With the
brakes fully released at all times, drive the vehicle
for 2 minutes at a speed of 5 mph, in any com-
bination of forward and reverse directions, through
a trough having a water depth of 6 inches. After
leaving the trough, immediately accelerate at
maximum rate to 30 mph without a brake applica-
tion. Immediately upon reaching that speed make
five stops, each from 30 mph at 10 fpsps for each
stop. After each stop (except the last), accelerate
the vehicle immediately at a maximum rate to a
speed of 30 mph and begin the next stop.

57.17 Spike stops. Make 10 successive spike
stops from 30 mph with the transmission in neu-
tral, with no reverse stops. Make spike stops by
applying a control force of 200 pounds while
recording control force versus time. Maintain con-
trol force until vehicle has stopped. At completion
of 10 spike stops, make 6 effectiveness stops from
60 mph.

87.18 Final inspection. Inspect —

(a) The service brake system for detachment or
fracture of any components, such as brake springs
and brake shoes or disc pad facing.

(b) The friction surface of the brake, the master
cylinder or brake power unit reservoir cover, and

seal and filler openings, for leakage of brake fluid
or lubricant.

(c) The master cylinder or brake power unit
reservoir for compliance with the volume and
labeling requirements of S5.4.2 and S5.4.3. In
determining the fully applied worn condition
assume that the lining is worn to ( 1 ) rivet or bolt
heads on riveted or bolted linings or (2) within
'/32 inch of shoe or pad mounting surface or
bonded linings, or (3) the limit recommended by
the manufacturer, whichever is larger relative to
the total possible shoe or pad movement. Drums
or rotors are assumed to be at nominal design
drum diameter or rotor thickness. Linings are
assumed adjusted for normal operating clearance
in the released position.

(d) The brake system indicator light(s), for
compliance with operation in various key posi-
tions, lens color, labeling, and location, in accord-
ance with S5.3.

S7.19 Moving barrier test. (Only for vehicles
that have been tested according to S7.7.2.) Load
the vehicle to GVWR, release parking brake and
place the transmission selector control to engage
the parking mechanism. With a moving barrier as
described in paragraph 3.3 of SAE Recommended
Practice J972 "Moving Barrier Collision Tests,"
November 1966, impact the vehicle from the front
at IVi mph. Keep the longitudinal axis of the bar-
rier parallel with the longitudinal axis of the
vehicle. Repeat the test, impacting the vehicle
from the rear.

Note: The vehicle used for this test need not be the
same vehicle that has been used for the brakini;
tests.

PART 571; S 105-15

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY
STANDARD NO. 108

Lamps, Reflective Devices, and Associated Equipment

Docket No. 80-9; Notice 6
RIN2127-AA12

AGENCY: National Highway Traffic Safety
Administration (NHTSA), DOT

ACTION: Final rule.

SUMMARY: This notice requires that trailers
which have an overall width of 80 inches or more
and a GVWR of more than 10,000 pounds, except
trailers manufactured exclusively for use as offices
or dwellings, be equipped on the sides and rear
with means for increasing their conspicuity. This
will enhance the likelihood of their detection at
night and under other conditions of reduced visi-
bility. Trailer manufacturers will be given a choice
of installing either retroreflective sheeting or
reflex reflectors. Under the rule, manufacturers of
retroreflective sheeting or reflectors will certify
compliance of their product with Standard No.
108, whether for use as original or as replacement
equipment. NHTSA estimates that the incidence of
accidents involving trailers struck in the side or
rear by other vehicles could be reduced 15 percent
by enhancing conspicuity as required by this rule.

DATES: The effective date for the rule is Decem-
ber 1, 1993. Petitions for reconsideration of the
rule must be received not later than 30 days after
the rule is published in the Federal Register.

ADDRESS: Petitions for reconsideration should
refer to Docket 80-9; Notice 6, and be submitted
to: Administrator, Docket Section, Room 5109,
Nassif Building, 400 Seventh Street, SW,
Washington DC 20590 (Docket hours are from
9:30 a.m. to 4 p.m.)

FOR FURTHER INFORMATION CONTACT: Pat-
rick Boyd, Office of Rulemaking (202-366-6346).

SUPPLEMENTARY INFORMATION: On Decem-
ber 4, 1991, NHTSA published a notice of pro-

posed rulemaking (NPRM) addressed to making
large trailers more visible on the road (56 FR
63474). The NPRM represented a tentative and
partial solution to a safety problem that has con-
cerned NHTSA for some years: the need to reduce
the incidence and severity of collisions with large
trailers during darkness or reduced visibility. As
early as May 27, 1980, the agency showed its
interest in enhanced conspicuity as a possible
solution. NHTSA issued an ANPRM (45 FR
35405) requesting comments on methods to
reduce such collisions by improving the conspicu-
ity of large commercial vehicles. Forty-two com-
ments were received, most of which favored the
concept.

NHTSA Fleet Study
Between 1980 and 1985, the agency conducted
a fleet study in which retroreflective material was
placed on truck-van trailer combinations in a
manner designed to increase their conspicuity.
The treatment of trailers consisted of outlining the
rear perimeter, and delineating the lower side. No
reflectorized mud flaps were used. The contractor
concluded that truck-trailer combinations
equipped with this material were involved in 15
percent fewer crashes (in which a trailer was
struck in the side or rear) than combinations lack-
ing the material.

1987 Request for Comments
The agency published a Notice of Request for
Comments on September 18, 1987 (52 FR 35345)
concerning the use of reflective material to
increase the conspicuity of large trucks and trail-
ers. The Notice recited the results of the fleet
study and sought comments on the test results as
well as the experiences others may have had with
the use of reflective material to enhance conspicu-
ity. Thirty-seven comments were received, most
agreeing that an effectiveness of 15 percent could

PART 571; S 108— PRE-391

be expected when all large vehicles were so
equipped with reflective material.

The Motor Carrier Safety Act of 1990
In response to the NHTSA fleet study. Con-
gress included in the Motor Carrier Safety Act of
1990 (Sec. 15, P.L. 101-500) a provision directing
the Secretary of Transportation "to initiate a rule-
making proceeding on the need to adopt methods
for making trucks or any category of trucks more
visible to motorists. . ."' not later than February
3, 1991, and to complete the rulemaking proceed-
ing not later than November 3, 1992.

The 1991 NPRM

NHTSA regards its 1991 NPRM, which is part
of a mlemaking proceeding begun before the
enactment of the Motor Carrier Safety Act of
1990, as responsive to the directive in that Act,
and this notice as the completion of the rule-
making proceeding mandated by Congress. Under
the NPRM, heavy trailers would be required to be
equipped with means for increasing their con-
spicuity because the agency tentatively concluded
that this would be an effective method to reduce
the incidence and severity of these crashes. The
proposal did not apply to large trucks without
trailers, since NHTSA' s PARS (Fatal Accident
Reporting System) accident data for 1989
indicated a much lower rate of conspicuity-related
accidents for large trucks alone than for large
truck-trailer combinations. The reader is referred
to the NPRM for a further discussion of the data.

Eighty-three comments were received in
response to the NPRM, representing the views of
manufacturers of vehicles, lamps, reflectors, and
retroreflective sheeting; commercial and private
fleet operators; the Teamsters union; States; insur-
ance companies; and citizens. A Summary of
Comments has been prepared and is available for
inspection in the docket. Details of the NPRM,
issues raised by the comments, and NHTSA's
responses are discussed below. NHTSA has incor-
porated recommendations on modifications to the
proposed retroreflective brightness values in a
Supplementary Notice of Proposed Rulemaking
(SNPRM) that is being prepared for publication.
The SNPRM will also incorporate proposals
regarding substitution of the retroreflective mate-
rials required by this notice for existing reflex
reflectors.

Effectiveness of Conspicuity Treatment
There was near unanimity among the com-
menters that a S retroreflective conspicuity treat-
ment would prevent accidents and save lives.
Most of the comments were directed towards the
details of implementing conspicuity treatment
rather than questioning its efficacy. The only
commenter who questioned the possible effective-
ness was UPS, only commenter who questioned
the principally because neither it nor its insurers
were aware of any data concerning conspicuity-
related accidents.

However, other commenters reported specific
data on conspicuity-related accidents and their
experiences with retroreflective treatments. Amer-
ican Inter-Fidelity Exchange, an insurer, began in
August 1990 to require 3M diamond grade mate-
rial on all insured platform trailers. In the 17-
month period before August 1990, it had $2 mil-
lion in claims with injuries and fatalities in con-
spicuity-related accidents. In the 18-month period
subsequent to July 1990, it experienced no costs,
no fatalities and few injuries in conspicuity
related accidents. The insured fleet numbered
3,500 flat bed trailers, and the miles traveled
totalled 3.5 million. Landstar commented that it
had retrofitted 6,500 trailers of a fleet of 9,000,
and had experienced a 50 percent reduction in
underride accidents, and a 90 percent reduction in
the cost of an average underride accident claim.
American Trucking Associations (ATA) reported
on a program to assess the effectiveness of detect-
ability where a conspicuity treatment was applied
to 11,000 trailers. It found that the fleet experi-
enced no conspicuity-related accidents in the year
since the first application. The effectiveness of
conspicuity treatment in daytime remains subject
to question. While the agency is not assuming
that there is a daytime benefit, it believes that the
overall effectiveness of retroreflective conspicuity
treatment is clearly demonstrated by the experi-
ence of these commenters.

Types of Trailers to Be Regulated
Since the various types of trailers differ from
one another in their configuration, NHTSA ten-
tatively concluded that the method of compliance
that may be appropriate for one type may not be
for another. For example, van-type trailers have
distinct rectangular side and rear perimeters to
which conspicuity enhancing materials could be
easily applied, while tank-type, platform trailers.

PART 571; S 108— PRE-392

or others do not. In order to ensure that the
requirements would be practicable for each type

• of trailer to which they apply, the agency devel-
oped and proposed definitions for four types of
trailers: "Dump," "Flatbed," "Tank," and
"Van." The requirements proposed for these
types differed somewhat based on the differences
in their configurations. Noting that these trailer
types account for 95 percent of the miles traveled
by heavy commercial trailers, NHTSA sought
comment on whether, for the sake of practicabil-
ity, the remaining 5 percent of trailers (those not
fitting any of the four proposed definitions)
should be excluded from compliance with the
conspicuity treatment requirements. Additionally,
NHTSA sought comment on the practicability of
applying conspicuity treatment to car carriers,
heavy haulers, and intermodal trailers.

Twenty-four general commenters wanted the
final rule to include all commercial trailers with-
out exceptions. They argued that it is preferable
to allow sufficient latitude in the spacing and
location of reflective materials that would facili-
tate compliance by all trailer types, than to
exclude some specific type on the basis of prac-

• ticability.
However, a number of other commenters
requested that specific trailer types be excluded
from the final rule. These trailer types were con-
tainer chassis, automobile transporter, side-loading
beverage, garbage, shiny aluminum, stainless van,
and house and recreational.

NHTSA considered each of these trailer types.
Container chassis trailers and garbage trailers
designed for carrying containers are motor
vehicles for purposes of the lighting standards of
NHTSA and the Federal Highway Administration
(FHWA). The sides of these types of trailers are
easily visible, even if low. Thus, the agency sees
no reason to exclude container chassis trailers or
garbage container trailers from the final rule.
Similarly, reflectorization of frame members
appears to be a practical solution for trailers with
bodies routinely covered by tarps, such as some
platform trailers.

Some commenters called for marking of
containers because a container mounted on a con-
tainer chassis resembles a van trailer. However, a
commenter representing the container industry
^ pointed out that the marking of containers is sub-

P ject to international treaty and that containers

equipped with conspicuity material would be

illegal to transport in some countries. Accord-
ingly, NHTSA has chosen not to require marking
of containers.

Commenters recommending an exclusion for
car transporters pointed out that the transporter
side rails may be lower than 15 inches and that
the vehicles transported are equipped with side
and rear reflex reflectors. However, the reflectors
on cars being transported on the carrier would not
provide the trailer with either a recognizable pat-
tern or a sufficient return of light to satisfy the
intent of the rule. NHTSA has chosen to allow
greater flexibility in the minimum mounting
height of retroreflective materials so that the side
rails of such vehicles may be equipped with con-
spicuity materials, if there is no practical alter-
native.

With respect to side-loading beverage trailers,
the rationale for exclusion appears to be based on
the need to mount retroreflective materials low
enough to clear the doors. NHTSA believes that
the minimum mounting height adopted by this
rule will be low enough to clear the doors, but,
in any event, neither the NPRM nor the final rule
prohibit application of conspicuity treatment to
doors.

Finally, the agency has considered the request
to exclude travel and house trailers. NHTSA long
ago relinquished jurisdiction over mobile homes
as trailers to the Department of Housing and
Urban Development. However, the agency does
regulate travel trailers. They are low mileage
vehicles that are generally parked off-road at
night, either on private property or trailer parks.
NHTSA has concluded that to exclude this type
of large trailer from the conspicuity requirement
would not have an adverse effect upon safety.
Accordingly, S5.7 will specify that the mle
applies to all large trailers except those that are
designed exclusively for living or office use.

The National Marine Manufacturers Associa-
tion commented that it does not consider its
small-boat industry to be affected by this rule-
making action because boats weighing 10,000
pounds or more are normally carried by commer-
cial rather than recreational trailers. This is not
always the case. Boats weighing less than 10,000
pounds may be carried by recreational trailers
with GVWRs over 10,000 pounds. Any boat
trailer whose GVWR exceeds 10,000 pounds will
be subject to this rule, whether the trailer is
commercial or recreational.

PART 571; S 108— PRE-393

There were also recommendations that trucks
and truck tractors be required to have conspicuity
treatments. NHTSA restricted the NPRM to trail-
ers to assure its cost effectiveness, because it
appeared that the vast majority of fatal accidents
in which trucks are struck at night involve tractor
trailer combinations. The argument for including
truck tractors is that they are not required to be
equipped with rear mounted turn signals or rear
identification lamps, and their tail/stop lamps are
closer together than on other vehicles. Hence,
from the rear at least, they are not a conspicuous
presence on the road at night. Preliminary
information available from PARS and General
Estimates System (GES) indicate that there is a
far higher accident involvement rate at night for
tractors than for trucks. The foregoing suggests
that a rear conspicuity treatment for truck tractors
may provide safety benefits. The agency is
considering the issue for possible inclusion in a
future rulemaking.

Manufacturer Choice of Type of Retroreflective

Materials
NHTSA tentatively decided in the NPRM that
manufacturers of heavy trailers should be required
to equip them with one of two proposed types of
retroreflective materials. Compliance would be
achieved using either retroreflective sheeting, or
an array of reflex reflectors which reflects the
same amount of light as the retroreflective sheet-
ing. Commenters supported the option. As
explained below, the final rule allows manufactur-
ers the choice of using retroreflective sheeting or
reflex reflectors.

Performance and Location of Retroreflective
Materials

NHTSA proposed, as alternatives, two sets of
requirements regarding pattern, color and location
for placing retroreflective sheeting on the side and
rear of trailers. One alternative was the pattern
tested in the fleet study, and the other was a
modification of the pattern that was expected to
increase visibility of the trailer side. Each alter-
native used about the same amount of
retroreflective sheeting, so that cost was not an
issue. However, the second alternative distributed
it in a way that was more generally applicable to
all trailers, avoided setting higher standards for
van trailers, and promoted uniformity of appear-
ance. Under either alternative, the material would
not be required to be affixed to discontinuous sur-

faces on the trailer body, and on items such as
door hinges, and lamp bodies. While the agency
proposed two specific configurations of conspicu-
ity treatment, it specifically sought comment on
whether variations of these alternatives would be
more appropriate for a final rule, or whether there
were other patterns more appropriate for con-
spicuity that should be proposed before a final
rule was adopted. NHTSA also asked that com-
menters discuss the cost-effectiveness of each pat-
tern, and provide support for their comments. The
agency anticipated that the final rule would
specify only one pattern, and not allow alternative
treatments. Associated issues on which NHTSA
requested comment were the appropriate level of
retroreflective performance of the sheeting, the
appropriate amount of sheeting used, whether the
sheeting should be patterned, and the appropriate
location of the sheeting, with respect to each of
the alternatives.

Configuration of Retroreflective Sheeting
For its proposed Alternative 1, the agency
chose a variation of the scheme used in the
NHTSA fleet study. Alternative 1 consisted of a
2-inch wide strip of retroreflective tape in
alternating red and white rectangles delineating
the lower side rails and outlining the rear perim-
eter of the trailer. The white rectangles would be
7 to 9 inches long, and the adjacent red rectangles
would be 2 to 4 inches longer than the white 12
rectangles. The material would be installed on the
perimeter of the rear of van trailers, and on as
much of the rear perimeter of other trailers as
practicable. The material would also be installed
horizontally on each side to indicate the length of
the trailer. The length of the material mounted on
the side inclusive of interruptions for discontinu-
ous surfaces would be within 3 feet of the full
length of the trailer. Allowing for interruptions
due to trailer design, the total length of the
individual horizontal strips provided would not be
less than 85 percent of the length of the material
were there no interruptions. The mounting height
of the horizontal side strips would be restricted to
the same height as other retroreflective devices
currently required by Standard No. 108; the center
would be not less than 15 inches above the road
surface; and the upper edge not more than 60
inches above it. In the NPRM, NHTSA noted
that, because of their configuration, van trailers
can best benefit from this type of treatment. The

PART ,'^7l; S

-PRE-394

large, flat surfaces of van trailers give the
observer a better basis for judgment of size,
shape, and distance compared with a flat bed
trailer having only a thin side or rear frame.

Alternative 2 redistributed the conspicuity
materials by placing more on the sides of the
trailers and using only a partial outline on the
rear. In NHTSA's view, this approach would pro-
vide better depth perception to the drivers of
vehicles approaching the trailer from the sides
and create a more standardized treatment across
trailer categories without requiring the use of
more conspicuity materials. In addition, this
approach would avoid "penalizing" van trailers
which, because of their large and flat surfaces,
would require, under Alternative 1, a greater use
of reflective materials than other trailer types.
Alternative 2 would provide slightly better side
recognition distance than Alternative 1, and iden-
tical rear recognition distance, as demonstrated by
laboratory and field results from an ongoing
University of Michigan Transportation Research
Institute (UMTRI) research for NHTSA (Contract
No. DTNH22-90-C-07017). Under both Alter-
native 1 and Alternative 2, red and white material
would be required to be installed horizontally on
each side to indicate the length of the trailer.
However, on the rear, the only red and white
material required by Alternative 2 would be at the
base of the perimeter, rather than the entire
perimeter as required by Alternative 1. In addi-
tion. Alternative 2 would require two vertical
white strips 12 inches high and 2 inches wide, to
indicate the width of the trailer, located within 12
inches of its full width. Similarly, two vertical
white strips would be located on the side, as close
to the front and rear as practicable, to indicate the
full length of the trailer. In addition, the upper
comers of the rear and both sides would be
required to be marked with two intersecting
pieces of white reflective sheeting, each 12 inches
by 2 inches. On the rectangular sides and rear of
a van trailer, the white strips, along with the red
and white base strips, would mark the bottom and
four corners of the sides and rear. However,
under Alternative 2, the white strips could also be
applied to trailers of irregular shape because they
would not be required to form a continuous
perimeter. White strips of sheeting would also be
added to the vertical members of the rear
underride protection equipment. Finally, white
sheeting 36 inches long and not less than 2 inches

high would be installed horizontally at the top
center of the trailer sides.

After consideration of the comments, and for
the reasons set forth below, NHTSA has decided
to adopt the side conspicuity configuration of
Alternative 1, and a rear conspicuity configuration
similar to Alternative 2.

Alternative 1 was preferred by the U.S. Postal
Service and Peterson Manufacturing. Alternative 2
was the choice of the National Private Truck
Council, Idaho State Police, National Automobile
Dealers Association, New Jersey Motor Vehicle
Administration, Minnesota Department of
Transportation, Wolf Technical Services, Dr.
Rudolf Mortimer, Insurance Institute for Highway
Safety, and Advocates for Highway & Auto
Safety. Other commenters suggested combining
elements of the two Alternatives. Many com-
menters desired discontinuous side striping to
reduce material expense, to accommodate irregu-
lar surfaces and to simplify repair.

NHTSA believes that an effective configuration
must identify the vehicle unambiguously as a
trailer, and allow an estimate of its size and the
closing distance to it. Given the decision to
include all large trailers (except house trailers),
practicability concerns require that the rule have
enough flexibility to be applied to all trailers. The
reduced detail of a more flexible rule creates a
greater dependence on the common sense of
trailer manufacturers to use materials in an effec-
tive way. The present widespread voluntary use of
conspicuity materials well adapted to the struc-
tures of various types of trailers gives the agency
confidence that a more flexible rule will be effec-
tive.

It is for this reason that NHTSA has chosen the
side conspicuity treatment of Alternative 1 and a
rear treatment similar to Alternative 2. The use of
broken side stripes, with at least 50 percent of the
length of the trailer covered, will make it prac-
ticable for ribbed trailers, and trailers with sides
partially obscured by equipment, to conform.
Under the rule, the distribution of spaces and
material must be as uniform as practicable and
indicate the full length and width of the trailer,
but they may be arranged to fit the structure of
the trailer. The colors must be placed in alternat-
ing sequence with no more than two-thirds of the
material in one color.

Flexibility in the vertical location of stripes is
necessary to allow lowboys, car carriers, and

PART 571; S 108— PRE-395

some tank trailers to comply. In order to promote
uniformity without excluding trailer types, the
stripes should be located for maximum visibility,
thus the rule requires that they be as close as
practicable to 4 feet above the road surface (the
lower edge of the body of the great majority of
trailers is about 4 feet above the road). Material
may be placed on trailer doors. NHTSA recog-
nizes that the location for maximum visibility on
certain trailers may be the trailer frame.

The rear treatment of Alternative 2 is a good
basis for a universal requirement. However, the
treatment element for the underride device was
the subject of both positive and negative com-
ment. Objections were based on the potential for
frequent damage that would cause trailers in use
to fail inspections by the FHWA. NHTSA has
observed that the horizontal bar of the underride
device is less subject to docking impacts than the
vertical bars because it is below most dock sur-
faces (and under a NHTSA proposal would be
even lower). Therefore, the final rule requires
retroreflective material to be applied to the hori-
zontal device, instead of the vertical ones as pro-
posed. NHTSA believes that the original con-
spicuity material should have a long useful life on
a large number of trailers, especially if it is
applied to a recessed surface. However, NHTSA
recognizes that routine damage, as a practical
matter, may be unavoidable for some trailers as a
consequence of their particular use. Therefore, the
FHWA will consider the exclusion of conspicuity
treatment from the rear underride device in any
future rulemaking concerning trailer conspicuity
requirements for vehicles subject to 49 CFR Pait
393 Parts and Accessories Necessary for Safe
Operation, and 49 CFR Part 396 Inspection and
Maintenance.

The rule requires conspicuity treatment of the
upper corners where they exist. For example, plat-
form trailers are required by the Motor Carrier
Safety regulations (49 CFR 393.106) to have a
front bulkhead, which can carry the upper comer
treatment. The rear stripe of material will be
continuous across the rear. To harmonize with
Motor Carrier Safety regulations (49 CFR
323.26), a 3-inch spacing between white material
and rear lamps is required (but red material may
be used adjacent to lamps to create a full width
stripe).

The UMTRI study specifically supports the rear
treatment of Alternative 2 that has been chosen

(see Figure 6.1(B) of its research report as cited
in the NPRM). UMTRI found comparable detec- ^^
tion distances between vehicles using a partial (' ~
and a full rear outline, and recommended the par-
tial outline as adequate for the task.

Although NHTSA' s standards cannot apply to
vehicles in use, NHTSA believes that the safety
benefits of conspicuity treatment are so
demonstratable that fleet owners will wish to
retrofit their trailers with conspicuity treatment.
NHTSA recommends that they employ a treat-
ment that corresponds with the requirements of
the final rule. Several commenters believe that
retrofit would be encouraged if NHTSA allowed
two 1-inch strips of material as an alternative to
one 2-inch strip. The final rule affords the manu-
facturer this option.

Peifonnance of Retroreflective Sheeting
The NPRM proposed a set of tests to evaluate
retroreflective sheeting. These tests would be con-
ducted in accordance with ASTM D 4956-90,
Standard Specification for Retroreflective Sheet-
ing for Traffic Control. The ASTM Specification
was chosen because NHTSA understood it to be
the Specification that manufacturers of
retroreflective sheeting were following as their
current manufacturing practice. The tests that
NHTSA proposed addressed retroreflective photo-
metric performance, flexibility, adhesion, impact
resistance, accelerated weathering, shrinkage,
resistance to fungus, and specular gloss. Com-
menters were also asked to discuss the use of 2-
inch wide white material of a minimum 250 can-
dela lux/square meter (for entrance angles of light
up to 30 degrees) as compared with wider, but
lower performance material or narrower, higher
performance material. The notice proposed that
material meeting the performance requirements
(other than reflectivity) for Type V, defined as a
super-high-intensity retroreflective sheeting, be
used to enhance the conspicuity of trailers. It pro-
posed minimum requirements for coefficients of
retroreflective intensity from research in progress
by UMTRI that were lower than those specified
by ASTM for Type V material. The proposed val-
ues were shown to be adequate, and more closely
represented the material fleet tested during the
Vector study.

A principal issue that was raised by the com- /^
ments was the brightness of the retroreflective V
material. Brightness is expressed in "specific

PART 571; S 108— PRE-396

intensity per unit area" or "SIA."" SIA is speci-
fied at observation angles of 0.2 degree and 0.5
degree, and light entrance angles of -4 degrees
and 30 degrees in both the ASTM specification
and the NPRM. The NPRM required the same
minimum performance at both entrance angles, a
specification intended to simulate a viewing dis-
tance of 740 feet to a trailer angled at 30 degrees
with respect to an approaching vehicle. Although
commercially available retroreflective material
easily exceeds the proposed minimum perform-
ance at -4 degrees, the lesser values proposed and
adopted for that angle adequately meet the need
for motor vehicle safety.

There were three questions raised about the
brightness of the material: whether the higher
specification of the ASTM should be adopted;
whether a system of wider stripes of material of
lower brightness should be allowed; and whether
a brightness should be specified at an entrance
angle greater than 30 degrees.

Insurance Institute of Highway Safety (IIHS),
Advocates for Highway & Auto Safety (Advo-
cates), Reflexite, and Transportation Safety
Equipment Institute (TSEI) supported the ASTM
specification. IIHS justified its comment by point-
ing out that the UMTRI study measured sight dis-
tances in good weather using subjects in a car
with clean headlamps and windshield. For this
reason, the proposed material brightness should be
increased to account for weather and car condi-
tions. NHTSA disagrees with this argument. The
values for brightness proposed are actually four
times greater than the minimum brightness that
UMTRI measured as adequate under good condi-
tions specifically to accommodate weather, dirt,
and other deleterious effects. Accordingly,
NHTSA has decided not to adopt the higher
ASTM specification.

UMTRI also indicated that wider stripes
of lower performance material would be as effec-
tive as the proposed material as long as the
amount of light reflected is preserved. Stimsonite
and 3M recommended that the final rule allow
wider material with equal specific intensity per
linear foot as the proposed 2-inch material. There-
fore, in the final rule, NHTSA is also allowing 3-
inch and 4-inch wide materials as options. The
three materials will be known respectively as
D0T-C2, D0T-C3 and D0T-C4. These materials
are believed to have the equivalent specific inten-

sity per linear foot as those proposed and adopted
for the 2-inch material. Figure 29 as adopted con-
tains the SIA values for D0T-C3 and D0T-C4
materials at the same observation and entrance
angles as the DOT-C2 materials.

Several commenters voiced a need for values at
an entrance angle of 45 degrees, and NHTSA ten-
tatively concurs. However, since the agency nei-
ther proposed a particular value nor even raised
the general issue of a value for that entrance
angle, NHTSA has included a proposed value in
the SNPRM that NHTSA is issuing simulta-
neously with the final rule. It also proposes that
the SIA value of 10 adopted for D0T-C2 red
material at the 0.5 degree observation angle and
entrance angles of -4 degrees and 30 degrees be
increased from 10 to 15 in order to be more
consistent with the performance specified at an
observation angle of 0.2 degree.

The Rulemaking Analysis section of the NPRM
stated that the average life of a trailer was
believed to be 14 years, and that one application
of the material should be sufficient for the life of
a trailer. Yellow Freight and Anya Carrol dis-
agreed. One cited the effects of chipping by
stones, scrapes by tree limbs and by cleaning
brushes. The other commented that loss of bright-
ness will occur in the absence of frequent clean-
ing of the materials.

UMTRI investigated material that had been
installed on fleets for at least 10 years, and found
a moderate loss of brightness due to age, and a
larger loss when the material was dirty. Material
manufacturers routinely guarantee the retention of
at least 50 percent of their original brightness for
7 years, while agreeing with UMTRI that the
service life is much longer. NHTSA' s proposed
SIA values took into account the effect of age and
dirt. Further, the agency made an effort to use
industry standards in the belief that those stand-
ards represented the best engineering solutions of
suppliers to the actual requirements of users.
Thus, no change to the proposal is needed in
response to considerations of durability or life of
retroreflective materials. Further, as noted later,
the FHWA will consider maintenance of the con-
spicuity treatment in any future rulemaking to
adopt the conspicuity requirements in the Federal
Motor Carrier Safety Regulations.

PART 571; S 108— PRE-397

Comments on Dimensions and Color of
Retroreflective Sheeting

With respect to retroreflective materials,
NHTSA requested views on the proposed length
and width of the red and white segments. NHTSA
noted that it was not proposing to allow corporate
logos as a substitute for the conspicuity materials.
Typically, logos consist of material of low bright-
ness, and they are not applied to the perimeters
of a vehicle but are centered on the sides and
rear. Logos may be used to supplement the con-
spicuity-enhancing materials that would be
required, however.

With respect to the requirements of Alternative
1 and Alternative 2 regarding pattern, color and
location, the agency sought comments on the
likely relative effectiveness of each on van trail-
ers, and on trailers other than van trailers.

With respect to Alternative 2, NHTSA asked
for views on whether it would improve or detract
from the side conspicuity of trailers as compared
with Alternative 1, and whether the 12-inch long
segments of white material contemplated should
be increased to 18 inches (NHTSA estimated this
would increase compliance costs about 8 percent).

NHTSA was also interested in comments on
how to improve the conspicuity of platform trail-
ers, and on the desirability of standardizing to the
maximum extent possible the treatment of all
trailers.

Very few commenters supported a red and
white alternating combination pattern. ATA,
Transamerica Leasing, and Robert Crail advocated
white only; Motor Vehicle Manufacturers
Association (MVMA) opposed white material on
the rear as a violation of State laws and a source
of possible masking of taillamps. Truck Trailer
Manufacturing Association (TTMA) and United
Parcel Service (UPS) opposed red on the sides.
Rudolf Mortimer recommended red on the rear
and yellow on the sides, while New Jersey sug-
gested a side treatment of yellow and white.

The final rule requires only a single stripe of
material on the side, and not a perimeter oudine.
Under this circumstance, the agency does not con-
sider stripes of yellow or white, used alone or
combined in alternating segments, as sufficiendy
distinct from common highway lane markings.
Red and white were the colors used in the
UMTRl study. NHTSA is confident that the pub-
lic will quickly learn to associate the red/white
stripe with trailers, and that the intuitive associa-

tion of red with danger will reinforce the learning.
Addressing MVMA's comment on the potential
masking of stop and turn signal lamps by white (
retroreflective material, the rule requires a mini-
mum spacing of three inches between white mate-
rial and adjacent red lamps. This is an existing
requirement of the Motor Carrier Safety Regula-
tions of the FHWA. Data available to NHTSA
does not indicate that the presence of red
retroreflective material adjacent to a red lamp
affects the perceptibility of the lamp.

UMTRI found that red and white segments of
equal length (about 12 inches) were most effec-
tive in connoting dangers to viewers. The NPRM
specified a somewhat different design in which
the red segments were longer (11 to 12 inches)
than the white (7 to 8 inches); this was based on
the length of presently available commercial prod-
ucts. In the final rule, the specification for both
segments is changed to 12 +/- 6 inches to
accommodate both the UMTRI study and
commercially available products, as well as to
afford flexibility to the trailer manufacturer.

NHTSA understands that New Jersey presently
requires retrofit of the sides of 53-foot trailers for
the rearmost 5 feet in yellow and white material,
and prohibits red and white material. As noted
eariier. Standard No. 108 has no retroactive effect
on trailers in use. However, under the preemption
clause (15 U.S.C. 1392(d)), the new vehicle
specifications of Standard No. 108 must be recog-
nized by the States, and New Jersey will be
unable to prohibit red and white material on the
sides of large trailers manufactured on and after
the effective date of this final rule. NHTSA there-
fore encourages New Jersey to review its require-
ment with a view towards allowing red and white
material for retrofit, and thereby promoting uni-
formity of conspicuity treatment.

Reflex Reflectors
The NPRM proposed that a manufacturer have
the choice of installing a system of reflex reflec-
tors instead of retroreflective sheeting. Reflex
reflectors that conform to SAE Standard J594f
Reflex Reflectors, January 1977 (the current
requirement in Standard No. 108), are rated in
terms of the absolute amount of light reflected in
proportion to the illumination striking them. The
size of the reflector and the brightness of the
material may be balanced to achieve the specified
amount of reflected light. Retroreflective sheeting.

PART 571; S 108— PRE-398

however, is rated in terms of the reflected light
per unit area, in proportion to the illumination.
Typically, three reflex reflectors (either white or
red, and independent of their size and shape)
would provide the same reflected light as one foot
of 2-inch D0T-C2 reflective sheeting of the same
color. The array of reflectors that the agency
believed equivalent to the proposed alternating
white/red retroreflective material scheme was a
group of two white reflectors alternating with a
group of three red reflectors, the center of each
reflector in a group being approximately 4 inches
from the center of the next one in that group. For
the elements of Alternative 2 that are all white,
if the reflex reflector performance were as above,
three white reflectors per foot would likely suf-
fice. Although these reflectors would be required
to conform to SAE J594f, they would also be
required to meet the additional performance
requirement of providing very high reflectivity
over a range of entrance angles of light from 30
degrees left to 30 degrees right. The additional
requirement ensured that the array of reflex
reflectors would deliver the same minimum
performance as the retroreflective sheeting. Reflex
reflectors molded in bars, resembling the sheeting
material, but narrower, were an obvious means of
implementation to NHTSA. For a multiple/retlec-
tor bar, each segment conforming to SAE J594f
would be labeled in order to indicate the number
of reflectors per length of bar. NHTSA requested
comments on this option, its likely relative
effectiveness as an alternative to the use of
retroreflective sheeting, and the likelihood of day-
time conspicuity enhancement compared with that
of sheeting.

Landstar and Wolf Technical Services argued
that reflectors are more prone to damage than
sheeting. Advocates claimed that the proposed
array would be less bright than sheeting, while
Grote argued exactly the opposite. NHTSA dis-
agrees with Grote and Advocates. The agency's
figures show for both sheeting and reflectors a
value of 3.87 cd/lux per foot of white treatment.
Grote mistakenly assumed that the values were
based upon equal areas rather than on equal light
return.

NHTSA recognizes that standards and durabil-
ity differ between sheeting and reflectors, but it
also recognizes that both products are apparently
capable of providing the minimum safety
performance necessary for vehicle conspicuity.

The final rule allows the option as proposed, with
a slight modification in the spacing requirement
to allow arrays a range of alternating color
lengths analogous to that permitted for sheeting,
and to eliminate the minimum spacing because
there is no conesponding maximum brightness for
sheeting material. Further, as already noted, the
Federal Highway Administration will conduct a
separate rulemaking to address concerns about the
maintenance of the conspicuity treatment required
by this rulemaking.

Combination Conspicuity Systems
Because the retroreflective capabilities of the
sheeting and reflectors specified by this standard
are deemed equivalent, there appears to be no
discernable reason why reflex reflectors meeting
the new requirements may not be installed in lieu
of retroreflective sheeting at any required location
on the side or on the rear, should practicality or
other conditions so dictate. Allowance of com-
bination conspicuity systems will afford greater
flexibility in complying with this rule.

Certification of Compliance of Retroreflective
Materials

The responsibility for compliance with the
performance requirements of the retroreflective
sheeting or reflex reflectors used to comply with
the conspicuity requirements rests upon the manu-
facturers of the sheeting or reflectors. Thus,
manufacturers who are providing these materials
to the trailer manufacturing industry and to
replacement parts outlets will have to certify
compliance with Standard No. 108, whether the
materials are intended for use as original or
replacement equipment. Such manufacturers must
also file information in accordance with 49 CFR
Part 566, Manufacturer Identification, if they
have not done so before.

Certification of the retroreflective materials will
be mandatory. For the retroreflective sheeting, it
will consist of the characters "D0T-C2," "DOT-
C3" or "D0T-C4" to distinguish the materials
from those conforming to Federal Specification
L-S-300, September 7, 1965, which is presently
permitted by paragraph. S5. 1.1.4 as an allowable
alternative for side reflex reflectors. These reflec-
tors may be marked "DOT" as an indication that
they meet this earlier version of L-S-300. How-
ever, it should be noted that they may not meet
ASTM D 4956-90, nor the conspicuity require-
ments of the final rule.

PART 571: S 108— PRE-399

Each reflex reflector installed for the purpose
of compliance with the conspicuity requirements
will also be required to be marked with the letters
DOT-C as a certification of compliance with the
conspicuity requirements (reflectors conforming
only to SAE J594f would continue to be marked
DOT if then- manufacturer chose that method of
certification). The spacing of the certification on
retroreflective materials occasioned some com-
ment. With respect to strips of all-white material,
NHTSA proposed to require the DOT-C symbol
to appear not less than every 12 inches. With
respect to strips of alternating red and white
material, the agency proposed that the DOT-C
symbol appear on each red segment and each
white segment. However, NHTSA requested com-
ments on an alternative such as one requiring that
the DOT-C symbol appear on one color alone,
with a paragraph added to Standard No. 108
specifying that such certification shall also be a
certification of the materials adjacent to it that are
of a different color. NHTSA requested comments
on whether individual segment marking would be
pracficable, or whether other methods may be
used that have the desired legal result for certifi-
cafion of materials. In the view of the com-
menters, the NPRM's alternative suggestion of
certification once per color cycle appeared to be
the most reasonable solution. NHTSA is adopting
this recommendation for materials of alternating
colors. With respect to the white material used to
mark the upper rear comers, certificadon will
appear at least once every 12 inches.

Possible Elimination of Other Lighting Equipment
Some commenters believe that existing require-
ments for lamps and reflectors on large trailers
should be modified when the conspicuity rule
becomes effective. UPS suggested eliminating
clearance lamps. TTMA argued that identification
lamps and reflectors will no longer be needed.
The American Petroleum Institute and ATA went
further, recommending in addition to these, the
elimination of all marker lamps. On the other
hand, Grote and Trucklite opposed the elimination
of any of the present lighting and reflecting
equipment.

The agency is opposed to the elimination of
any lamps, since the conspicuity treatment is
intended to be a passive augmentation of the
existing active lighting equipment. Safety depends
on lamps being present and functioning in poor

weather conditions, or when the trailer is dirtier
than normal, conditions that work against the full
effectiveness of reflected light. f-

However, rear and side reflex reflectors that are
mounted at the same height as the conspicuity
stripes could be considered redundant, even
though amber side reflectors would be replaced
with red and white conspicuity treatment. The
agency is pursuing this matter further through the
SNPRM that is being prepared for publication.

Shift to Expression of Measurements in Metric
System Units

In implementation of the Department's policy
to use the metric system where possible in
rulemakings, the values that were proposed
conventionally in the NPRM are adopted using
metric units. For example, the strip of material
whose width was 2 inches in the NPRM becomes
one whose width is 50 mm in the final rule. This
shift will result temporarily in Standard No. 108
using the conventional system of measurement in
one section, and the metric system in another.
However, eventually Standard No. 108 will be
converted entirely to metric expression, in accord-
ance with a NHTSA timetable.

Associated Rulemaking: Rear Underride V

Protection
The agency is also seeking to reduce the sever-
ity of accidents in which vehicles strike the rear
ends of trailers through rulemaking regarding rear
underride protection. To the extent that the num-
ber and severity of rear end crashes would be
mitigated by enhancing conspicuity, the benefits
of a rear underride rule might be lessened.
Interested persons were advised to be aware of
the relatedness of these two rulemaking actions in
preparing their comments on each.

Related Rulemaking: Federal Highway
Administration
The FHWA has worked with NHTSA to ensure
that its standards are compatible with the Federal
motor vehicle safety standards wherever possible.
As part of this effort, the FHWA will continue to
adopt the appropriate sections of NHTSA' s stand-
ards into the Federal Motor Canier Safety Regu-
lations (FMCSRs). If amendments to 49 CFR
Parts 393, Parts and Accessories Necessary for
Safe OperationTl, and 396. Inspection Repair ^
and Maintenance, of the FMCSRs are necessary V_
to ensure the continued presence and proper

PART 571; S 108— PRE-400

performance of conspicuity enhancements on
large trailers, the FHWA will address the issue in
a separate rulemaking.

Effective Dote
Because of the relatively simple efforts that
would be necessary to comply with the conspicu-
ity requirements, and the fact that trailers are not
modified on a model year basis, the agency pro-
posed an effective date of the final rule that
would be 12 months after publication of the final
rule. Accordingly, the effective date of the final
rule is December 1, 1993.

Rulemaking Analyses
Executive Order 12291 (Federal Regulation)
and DOT Regulatory Policies and Procedures.
NHTSA has considered the impacts of this rule-
making action and has determined that although it
is not major within the meaning of Executive
Order 12291 "Federal Regulation," it is signifi-
cant under Department of Transportation regu-
latory policies and procedures because it involves
a matter of substantial Congressional and public
interest. The rulemaking will not have an effect
upon the economy in excess of $100 million a
year. NHTSA estimates that the cost to equip all
new trailers manufactured in a calendar year will
be $17.3 million. This estimate will not be
affected by the proportion of manufacturers which
choose sheeting material versus reflex reflectors
molded in bars as their means of compliance. The
agency further estimates that once all trailers
within the affected categories of trailers comply
with the new requirements, 2,113 accidents will
be prevented and 9,052 others will be mitigated
annually. The resulting reduction in property dam-
age will be $41.75 million. Thus, the cost of the
conspicuity system will be offset by the savings

in property damage alone. However, the expected
prevention of injuries and fatalities is the reason
that NHTSA is acting to improve the visibility of
large trailers.

NHTSA estimates that the life of the average
trailer is 14 years. Agency research indicates that
the original application of conspicuity materials
can be expected to perform during the entire life
of the trailer. NHTSA has no studies allowing it
to quantify a reduction in fatalities and injuries
that would be expected from use of conspicuity
material. However, it is reasonable to expect
prevention of some 80 fatalities and 1,315 injuries
if they were reduced in proportion to the expected
reduction in accidents. There is no cost assigned
to preventing those fatalities and injuries because
the reduction of property damage alone is
expected to exceed the cost of conspicuity mate-
rials and labor. The costs and benefits are cal-
culated in 1992 dollars. A Regulatory Evaluation
has been prepared and is available for examina-
tion by the public in the docket.

Regulatory Flexibilit}' Act. The agency has also
considered the effects of this rule in relation to
the Regulatory Flexibility Act. I certify that this
rule will not have a significant economic effect
trailer upon a substantial number of small entities.
Although trailer manufacturers are generally small
businesses within the meaning of the Regulatory
Flexibility Act, the cost impact of complying with
the regulation will not be significant. The agency
estimates that compliance costs to the trailer
buyer will average $102 per trailer to the
consumer. As for manufacturers of retroreflective
materials and reflex reflectors, NHTSA notes that
retroreflective materials that conform to ASTM D
4956-90 Type V are presently being manufac-
tured, and that the cost to add DOT certification
symbols should be only about $.11 a trailer. Fur-
ther, small organizations and governmental juris-
dictions will not be significantly affected as the
price of new trailers equipped with conspicuity
treatment will not, as already noted above, be
more than minimally impacted. Accordingly, no
Regulatory Flexibility Analysis has been prepared.

Executive Order 12612 {Federalism}. This
action has been analyzed in accordance with the
principles and criteria contained in Executive
Order 12612 on "Federalism." It has been deter-
mined that the rule does not have sufficient fed-
eralism implications to warrant the preparation of
a Federalism Assessment.

PART 571; S 108— PRE^Ol

National Environmental Policy Act. NHTSA
has analyzed this rule for purposes of the
National Environmental Policy Act. The rule will
not have a significant effect upon the environ-
ment. Retroreflective material is non-toxic in
nature. Further, the rule will not have an effect
upon fuel consumption.

Paperwork Reduction Act. The labeling require-
ments associated with this rule have been submit-
ted to the Office of Management and Budget for
approval in accordance with 44 U.S.C. chapter
35. ADMINISTRATION: National Highway Traf-
fic Safety Administration; TITLE: Labeling of
reflective material for trailer conspicuity; NEED
FOR INFORMATION: Identification of reflective
material as conforming to requirements; ANTICI-
PATED USE OF INFORMATION: Routine
trailer inspection by Federal Highway Administra-
tion; FREQUENCY; On occasion; BURDEN
ESTIMATE: 200 hours; RESPONDENTS: 2;
FORM(S): None; AVERAGE BURDEN HOURS
PER RESPONDENT: 100; For further informa-
tion contact: The Information Requirements Divi-
sion, M-34, Office of the Secretary of Transpor-
tation, 400 Seventh Street, S.W., Washington,
D.C. 20590, (202) 366-4735.

List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety. Motor vehicles
PART 571— FEDERAL MOTOR VEHICLE
SAFETY STANDARDS.

In consideration of the foregoing. 49 CFR part
571 is amended as follows:

1. The authority citation for part 571 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403, 1407;
delegation of authority at 49 CFR 1.50.
S571.108 [Amended]

2. Section S3 Application is amended to read:
S3 Application. This standard applies to:

(a) Passenger cars, multipurpose passenger
vehicles, trucks, buses, trailers (except pole trail-
ers and trailer converter dollies), and motorcycles;

(b) Retroreflective sheeting and reflex reflec-
tors manufactured to conform to 85. 7 of this
standard; and

(c) Lamps, reflective devices, and associated
equipment for replacement of like equipment on
vehicles to which this standard applies.

3. Sections S5.7, S5.7.I and S5.7.2, S5.7 are
redesignated S5.8, S5.8.1 and S5.8.2, and a new
section is added to read: p

S5.7 Conspicuity Systems. Each trailer of 80 or
more inches overall width, and with a GVWR
over 10,000 lbs. manufactured on or after Decem-
ber 1, 1993, except a trailer designed exclusively
for living or office use, shall be equipped with
either retroreflective sheeting that meets the
requirements of S5.7.1, reflex reflectors that meet
the requirements of S5.7.2, or a combination of
retroreflective sheeting and reflex reflectors that
meet the requirement of S5.7.3.

S5.7.1 Retroreflective sheeting. Each trailer to
which S5.7 applies that does not conform to
S5.7.2 or S5.7.3 shall be equipped with
retroreflective sheeting that conforms to the
requirements specified in S5.7.1.1 through
S5.7.1.5.

S5.7.1.1 Construction. Retroreflective sheeting
shall consist of a smooth, flat, transparent exterior
film with retroreflective elements embedded or
suspended beneath the film so as to form a non-
exposed retroreflective optical system.

S5.7.1.2. Performance requirements. Retro- z_
reflective sheeting shall meet the requirements of '
ASTM D 4956-90, Standard Specification for
Retroreflective Sheeting for Traffic Control, for
Type V Sheeting, except for the photometric
requirements, and shall meet the minimum photo-
metric performance requirements specified in Fig-
ure 29.

S5.7.1.3 Sheeting pattern, dimensions, and rel-
ative coefficients of retroreflection.

(a) Retroreflective sheeting shall be applied in
a pattern of alternating white and red color seg-
ments to the side and rear of each trailer, and in
white to the upper rear corners of each trailer, in
the locations specified in S5.7.1.4, and illustrated
in Figure 30.

(b) Except for a segment that is trimmed to
clear obstnictions, or lengthened to provide red
sheeting near red lamps, each white or red seg-
ment shall have a length of 300mm +1- 150 mm.

(c) Neither white nor red sheeting shall rep-
resent more than two thirds of the aggregate of
any continuous strip marking the width of a
trailer, or any continuous or broken strip marking ~
its length.

PART 571; S I(

(d) Retroreflective sheeting shall have a width
of 50 mm (Grade DOT-C2). 75 mm (Grade DOT-
A C3), or 100 mm (Grade D0T-C4).
^^ (e) The coefficients for retroreflection of each

segment of red or white sheeting shall be not less
than the minimum values specified in Figure 29
of diis standard for grades D0T-C2, D0T-C3,
and D0T-C4.

S5.7.1.4 Location, (a) Retroreflective sheeting
shall be applied to each trailer on the side and
rear as specified below, but need not be applied
to discontinuous surfaces such as outside ribs,
stake post pickets on platform trailers, and exter-
nal protruding beams, or to items of equipment
such as door hinges and lamp bodies.

(b) The edge of white sheeting shall be not be
located closer than 75 mm to the edge of the
luminous lens area of any lamp that is required
by this standard.

(c) The edge of red sheeting shall not be
located closer than 75 mm to the edge of the
luminous lens area of any lamp that is required
by this standard.

55. 7. 1.4.1 Rear. Retroreflective sheeting shall

• be applied to the rear of each trailer as follows:
(a) Element 1: a horizontal strip of sheeting in
alternating colors across the full width of the
trailer as close to the extreme edges as prac-
ticable, and as close as practicable to 1.25 meters
above the road surface.

(b) Element 2: two pairs of white strips of
sheeting, each pair consisting of strips 300 mm
long of grade D0T-C2 (50 mm wide), D0T-C3
(75 mm wide), or D0T-C4 (100 mm wide),
applied horizontally and vertically to the right and
left upper contours of the body, as viewed from
the rear, as close to the top of the trailer and as
far apart as practicable.

(c) Element 3; a strip of sheeting in alternating
colors across the full width of the horizontal
member of the rear underride protection device.

55.7. 1.4.2 Side. Retroreflective sheeting shall
be applied to each side of a trailer as follows:

(a) A horizontal strip of sheeting in alternating
colors, originating and terminating as close to the
front and rear ends as practicable, and as close as
practicable to 1.25 m above the road surface
except that, at the location chosen, the strip shall
^ not be obscured in whole or in part by other

W motor vehicle equipment or trailer cargo. The

strip need not be continuous as long as not less

than half of the length of the trailer is covered
and the spaces are distributed as evenly as prac-
ticable.

(b) If necessary to clear rivet heads or other
similar obstructions, grade DOT-C2 retroreflective
sheeting may be separated into two 25 mm wide
strips of the same length and color, separated by
a space of not more than 25 mm, and used in
place of the retroreflective sheeting that would
otherwise be applied.

S5.7.1.5 Certification. The letters DOT-C2,
D0T-C3, or D0T-C4, as appropriate, constituting
a certification that the retroreflective sheeting
conforms to the requirements of S5.7.1.2, shall
appear at least once on the exposed surface of
each white or red segment of retroreflective sheet-
ing, and at least once every 300 mm on
retroreflective sheeting that is white only. The
characters shall be not less than 3 mm high, and
shall be permanently stamped, etched, molded, or
printed in indelible ink.

S5.7.2 Reflex Reflectors. Each trailer to which
S5.7 applies that does not conform to S5.7.1 or
S5.7.3 shall be equipped with reflex reflectors in
accordance with this section.

S5. 7. 2. 1(a) Each reflex reflector shall conform
to SAE Standard J594f, Reflex Reflectors, January
1977.

(b) Each red reflex reflector shall also provide,
at an observation angle of 0.2 degree, not less
than 310 millicandelas/lux at any light entrance
angle between 30 degrees left and 30 degrees
right, including an entrance angle of degree.

(c) Each white reflex reflector shall also pro-
vide, at an observation angle of 0.2 degree, not
less than 1290 millicandelas/lux at any light
entrance angle between 30 degrees left and 30
degrees right, including an entrance angle of
degree.

S5. 7.2.2 Reflex reflectors shall be installed and
located as specified below:

(a) In the same locations and in the same
length in which retroreflective sheeting is required
by S5.7.1.4 to be applied in alternating colors,
reflex reflectors shall be installed in a repetitive
pattern of two or three white reflex reflectors
alternating with two or three red reflex reflectors,
with the center of each reflectror more than 100
mm from the center of each adjacent reflector.

(b) In the same locations and in the same
length in which white retroreflective sheeting is

PART 571; S

-PRE^03

required by S5.7.1.4 to be installed, white reflex
reflectors shall be installed, with the center of
each white reflex reflector not more than 100 mm
the center of each adjacent reflector.

S5.7.2.3 Certification. The exposed surface of
each reflexreflector shall be marked with the let-
ters DOT-C which constitutes a certification that
the reflector conforms to all applicable require-
ments of section 571.108 of this part. The certifi-
cation shall be not less than 3 mm high, and
permanently stamped, etched, molded or printed
in indelible ink.

S5.7.3 Combination of sheeting and reflectors.
Each trailer to which S5.7 applies that does not
conform to S5.7.1 or S5.7.2, shall be equipped
with retroreflective materials that meet the
requirements of S5.7.1 except that reflex reflec-
tors that meet the requirements of S5.7.2.1, and
that are installed in accordance with S5.7.2.2,
may be used instead of any corresponding ele-
ment of retroreflective sheeting located as
required by S5.7.1.4.

4. Table I is amended by adding the following
at the end thereof:

Multipurpose pas- Trailers Applicable

Sanger vehicles, SAE

trucks, and buses standards

5. Table II is amended by adding the following
after the requirements for "Intermediate side _
reflex reflectors": ^

Item Multipurpose pas- Trailers

senger vehicles,
trucks, and buses

Conspicuity See S5.7 See S5.7

6. Figure 29 is added as follows:

OBSERVATION ANGLE

Height above
road sur-
face

Entrance Angle

0.2 Degree
White Red

0.5 Deg

ree

Grade

White

Red

-4 degrees
30 degrees

250
250

60
60

65
65

10
10

DOT-C2
DOT-C2

-4 degrees
30 degrees

165
165

40
40

43
43

10
10

DOT-C3
DOT-C3

-4 degrees
30 degrees

125
125

30
30

33
33

DOT-C4
DOT-C4

Conspicuity

Figure 29 Minimum Photometeric Performance

of Retroreflective Sheeting (Canadela/Lux/

Square IVIeter)

7. Figure 30 is added as follows:
Issued on: December 3, 1992.

Marion C. Blakey
Administrator

57 F.R. 58406
December 10, 1992

VAN PLATFORM

Figure 30 Typical Trailer Conspicuity Treatments

PART 571; S 108— PRE-404

MOTOR VEHICLE SAFETY STANDARD NO. 108

Lamps, Reflective Devices, and Associated Equipment-Passenger Cars,

Multipurpose Passenger Vehicles, Trucks, Buses, Trailers, and Motorcycles

(Docket No. 69-18)

51 Scope. This standard specifies requirements
for original and replacement lamps, reflective
devices, and associated equipment.

52 Purpose. The purpose of this standard is to
reduce traffic accidents and deaths and injuries
resulting from traffic accidents, by providing ade-
quate illumination of the roadway, and by enhanc-
ing the conspicuity of motor vehicles on the public
roads so that their presence is perceived and their
signals understood, both in daylight and in dark-
ness or other conditions of reduced visibility.

53 Application. [This standard applies to:

(a) Passenger cars, multipurpose passenger

vehicles, trucks, buses, trailers (except pole trail-
^ ers and trailer converter dollies), and motorcycles;
^ (b) Retroreflective sheeting and reflex reflectors

manufactured to conform to S5.7 of this standard;

and

equipment for replacement of like equipment on

vehicles to which this standard applies. (57 F.R.

58406— December 10, 1992. Effective: December 1,

1993)]

54 Definitions. "Aiming Reference Plane"
means a plane which is perpendicular to the
longitudinal axis of the vehicle and tangent to the
forwardmost aiming pad on the headlamp.

Beam contributor means an indivisible optical
assembly including and lens, reflector, and light
source, that is part of an integral beam
headlighting system and contributes only a por-
tion of a headlamp beam.

Cargo lamp is a lamp that is mounted on a
multipurpose passenger vehicle, truck, or bus for
the purpose of providing illumination to load or
unload cargo.

Direct reading indicator means a device that is
m mounted in its entirety on a headlamp or

W headlamp aiming or headlamp mounting equip-

ment, is part of a VHAD, and provides informa-
tion about headlamp aim in an analog or digital
fonnat.

Effective projected luminous lens area means
that area of the projection on a plane perpendicu-
lar to the lamp axis of the portion of the light-
emitting surface that directs light to the photo-
metric test pattern, and does not include mounting
hole bosses, reflex reflector area, beads or rims
that may glow or produce small areas of
increased intensity as a result of uncontrolled
light from smallareas {V2 deg. radius around the
test point).

Flash means a cycle of activation and deactiva-
tion of a lamp by automatic means, continuing
until stopped either automatically or manually.

Headlamp test fixture means a device designed
to support a headlamp or headlamp assembly in
the test position specified in the laboratory tests
and whose mounting hardware and components
are those necessary to operate the headlamp as
installed in a motor vehicle.

Integral Beam Headlamp means a headlamp
comprising an integral and indivisible optical
assembly including lens, reflector, and light
source, that is neither a standardized sealed beam
headlamp designed to conform to paragraph S7.3
nor a replaceable bulb headlamp designed to con-
form to paragraph S7.5.

Multiple compartment lamp means a device
which gives its indication by two or more sepa-
rately lighted areas which are joined by one or
more common parts, such as a housing or lens.

Multiple lamp arrangement means an array of
two or more separate lamps on each side of the
vehicle which operate together to give a signal.

Remote reading indicator means a device that
is not mounted in its entirety on a headlamp or
headlamp aiming or headlamp mounting equip-
ment, but otherwise meets the definition of a
direct reading indicator.

PART 571; S

(Rev. 12/10/92)

Replaceable bulb headlamp means a headlamp
comprising a bonded lens and reflector assembly
and one or two standardized replaceable light
sources.

Seasoning means a process of energizing the
filament of a headlamp, at design voltage, for a
period of time equal to 1 percent of average rated
laboratory life.

Standardized replaceable light source means an
assembly of a capsule, base, and terminals, that
meets the requirements of S7.6.

Vehicle headlamp aiming device or VHAD
means motor vehicle equipment permanently
installed on a motor vehicle by the manufacturer
of the vehicle, which is used for determining the
horizontal and vertical aim of headlamps.

S5 Requirements.

S5.1 Required motor veliicle lighting equip-
ment.

S5.1.1 Except as provided in succeeding para-
graphs of S5.1.1, each vehicle shall be equipped
with at least the number of lamps, reflective
devices, and associated equipment specified in
Tables I and III and S7, as applicable. Required
equipiTient shall be designed to conform to the
SAE Standards or Recommended Practices ref-
erenced in those tables. Table I applies to multi-
purpose passenger vehicles, trucks, trailers, and
buses, 80 or more inches in overall width. Table
III applies to passenger cars and motorcycles and
to multipuipose passenger vehicles trucks, trailers,
and buses, less than 80 inches in overall width.

55.1.1.1 A truck tractor need not be equipped with
turn-signal lamps mounted on the rear if the turn
signal lamps at or near the front are so constructed
(double-faced) and so located that they meet the
requirements for double-faced turn signals speci-
fied in SAE Standard J588e, Turn Signal Lamps,
September 1970.

55.1.1.2 A truck tractor need not be equipped with
any rear side marker devices, rear clearance
lamps, and rear identification lamps.

55.1.1.3 Intermediate side marker devices are not
required on vehicle less than 30 feet in overall
length.

55.1 .1 .4 Reflective material conforming to Federal
Specification L-S-300, Sheeting and Tape, Reflec-
tive: Non-exposed Lens, Adhesive Backing, f-
September 7, 1965, may be used for side reflex
reflectors if this material, as used on the vehicle,
meets the performance standards in either Table I

or Table lA of SAE Standard J594f, Reflex Reflec-
tors, January 1977.

55.1.1.5 The turn signal operating unit on each
passenger car and multipurpose passenger vehicle,
truck, and bus less than 80 inches in overall width
shall be self-canceling by steering wheel rotation
and capable of cancellation by a manually oper-
ated control.

55.1.1.6 [(a)] Each stop lamp manufactured to
replace a stop lamp that was designed to conform
to SAE Standard J586b Stop Lamps, June 1966,
may also be designed to conform to J586b. It shall
meet the photometric minimum candlepower
requirements for Class A red turn signal lamps
specified in SAE Standard J575d, Tests for Motor
Vehicle Lighting Devices and Components, August
1967. Each such lamp manufactured for use on a
passenger car and on a multipurpose passenger
vehicle, truck, trailer, or bus less than 80 inches ^
in overall width shall have an effective projected
luminous area not less than 3'/2 square inches. If
multiple compartment lamps or multiple lamps are
used, the effective projected luminous area of each
compartment or lamp shall be not less than 3'/2
square inches; however, the photometric require-
ments may be met by a combination of compart-
ments or lamps.

[(b) Each stop lamp manufactured to replace a
stop lamp that was designed to conform to SAE
Standard J586c, Stop Lamps, August 1970, may
also be designed to conform to J586c. (55 F.R.
20158— May 15, 1990. Effective: December 1,
1990.)]

[(c) A multipuipose passenger vehicle, truck,
bus, or trailer whose overall width is 80 inches or
more, manufactured on or before November 30,
1991, and whose stop lamps are located more
than 22 inches apart, may be equipped with stop
lamps designed to conform to SAE Standard
J586c, Stop Lamps, August 1970." (55 F.R.
20158— May 15, 1990. Effective: December 1,
1990.)]

55.1.1.7 (a) Each turn signal lamp manufactured V
to replace a turn signal lamp that was designed to

(Rev. 5/15/90)

PART 571; S 108-2

conform to SAE Standard J588d Turn Signal
Lamps. June 1966, may also be designed to con-
forni to J588d, and shall meet the photometric
minimum candlepower requirements for Class A
turn signal lamps specified in SAE Standard
J575d, Tests for Motor Vehicle Lighting Devices
and Components, August 1967. Each such lamp
manufactured for use on a passenger car and on
a multipurpose passenger vehicle, truck, trailer or
bus less than 80 inches in overall width shall have
an effective projected luminous area not less than
3V2 square inches. If multiple compartment lamps
or multiple lamps are used, the effective projected
luminous area of each compartment or lamp shall
be not less than 3'/2 square inches; however, the
photometric requirements may be met by a com-
bination of compartments or lamps. Each such
lamp manufactured for use on a multipurpose pas-
senger vehicle, truck, trailer or bus 80 inches or
more in overall width shall have an effective pro-
jected luminous area not less than 12 square
inches.

[(b) Each turn signal lamp manufactured to
replace a turn signal lamp that was designed to
conform to SAE Standard J588e, Turn Signal
Lamps. September 1970, may also be designed to
conform to SAE Standard J588e. Note 6 of Table
1 of SAE Standard J588e does not apply. A stop
lamp that is not optically combined with a turn
signal lamp shall remain activated when the turn
signal is flashing. (55 F.R. 20158— May 15, 1990.
Effective: December 1, 1990.)]

[(c) A multipurpose passenger vehicle, truck,
bus, or trailer, whose overall width is 80 inches
or greater, manufactured on or before November
30, 1991, and whose turn signal lamps are located
more than 22 inches apart, may be equipped with
turn signal lamps designed to conform to SAE
Standard J588e, Turn Signal Lamps. September
1970. (55 F.R. 20158-May 15, 1990. Effective:
December 1, 1990.)]

S5.1.1.8 For each motor vehicle less than 30 feet
in overall length, the photometric-minimum
candlepower requirements for side marker lamps
specified in SAE Standard J592e, Clearance, Side
Marker, and Identificatiou Lamps. July 1 972, may
be met for all inboard test points at a distance of

15 feet from the vehicle and on a vertical plane
that is perpendicular to the longitudinal axis of the
vehicle and located midway between the front and
rear side marker lamps.

55.1.1.9 A boat trailer whose overall width is 80
inches or more need not be equipped with both
front and rear clearance lamps provided an amber
(to front) and red (to rear) clearance lamp is
located at or near the midpoint on each side so as
to indicate its extreme width.

55.1.1.10 Multiple license plate lamps and backup
lamps may be used to fulfill the requirements of
the SAE Standards applicable to such lamps ref-
erenced in Tables I and III.

55.1.1.11 [A parking lamp, tail lamp, stop lamp
manufactured to replace a stop lamp designed to
conform to SAE Standard J586c. Stop Lamps,
August 1970, or turn signal lamp manufactured to
replace a turn signal lamp that was designed to
conform to SAE Standard J588e, Turn Signal
Lamps. September 1970, shall meet the minium
percentage specified in Figure la of the cor-
responding minimum allowable value specified in
Table 1 and Table 3 of SAE J588 NOV 84 Turn
Signal Lamps except that motorcycle turn signal
lamps need meet only one-half of the minimum
photometric values specified in Figure lb. (55 F.R.
20158— May 15, 1990. Effective: December 1,
1990.)]

Figure 1 a. — Required percentages of minimum
candlepower of Figure lb.

(iteg)

Turn
signal

Srop

Park-
inf>

Tail

5L. 5R

20L. 20R

12.5

5U. 5D

lOL, lOR

37.5

87.5

lOL, lOR

5L, 5R

100

Note. — Minimum design candlepower requirements are
determined by multiplying the percentages given in this Figure by
the minimum allowable candlepower values in Figure lb. The
resulting values shall be truncated after one digit to the right of the
decimal point.

PART 571; S 1(

(Rev. 5/15/90)

Figure lb. — Minimum and maximum allow-
able candlepower values.

Lighted Sections

Lamp

/ 2 9

Stop 80/300 95/360 110/420

Tail' 2/18 3.5/20 5.0/25

Parking^ 4.0/125

Red turn signal 80/300 95/360 110/420

Yellow turn signal rear 130/750 150/900 175/1050

Yellow turn signal front 200/- 240/- 275/-

Yellow turn signal front ' 500/- 600/- 685/-

' Maximum at H or above.

-The maximum candlepower value of 125 applies to all test
points at H or above. The maximum allowable candlepower value
below H is 250.

-'Values apply when the optical axis (filament center) of the front-
turn signal is at a .spacing less than 4 inches (10 cm.) from the
lighted edge of the headlamp unit providing the lower beam, or from
the lighted edge of any additional lamp installed as original
equipment and which supplements the lower beam.

S5.1.1.12 [A parking lamp, tail lamp, stop lamp
manufactured to replace a stop lamp designed to
conform to SAE Standard J586c Stop Lamps,
August 1970, or turn signal lamp manufactured to
replace a turn signal lamp designated to conform
to the SAE Standard J588e, Turn Signal Lamps,
September 1970, is not required to meet the mini-
mum photometric value at each test point speci-
fied in this standard if the sum of the percentages
of the minimum candlepower measured at the test
points is not less than that specified for each
group listed in Figure Ic. (55 F.R. 20158— May 15,
1990. Effective: December 1, 1990.)]

Figure Ic. — Sum of the percentages of
grouped minimum candlepower.

Croups and test points J"™^ Slop ''"^'^' Tail

10U-5L, 5U-20L, 5D-20L, lOD-

5L 65 65 60 70

5U-10L. H-IOL, 5D-10L 125 125 75 120

H-5L, 5U-V, NV, 5D-V, H-5R . 475 475 420 480

5U-10R, H-IOR, 5D-10R 125 125 75 120

10U-5R, 5U-20R, 5D-20R,

lOD-SR 65 65 60 70

55.1.1.13 Each passenger car, and each multipur-
pose passenger vehicle, tiuck, and bus of less than
80 inches overall width, shall be equipped with a
turn signal operating unit designed to complete a
durability test of 100,000 cycles.

55.1.1.14 A trailer that is less than 30 inches in
overall width may be equipped with only one tail
lamp, stop lamp, and rear reflex reflector, which
shall be located at or near its vertical centerline.

55.1.1.15 A trailer that is less than 6 feet in over-
all length, including the tongue, need not be
equipped with front side marker lamps and front
side reflex reflectors. '

55.1.1.16 A lamp designed to use a type of bulb
that has not been assigned a mean spherical
candlepower rating by its manufacturer and is not
listed in SAE Standard J 573d, Lamp Bulbs and
Sealed Units, December 1986, shall meet the
applicable requirements of this standard when
used with any bulb of the type specified by the
lamp manufacturer, operated at the bulb's design
voltage. A lamp that contains a sealed-in bulb
shall meet these requirements with the bulb oper-
ated at the bulb's design voltage.

55.1.1.17 Except for a lamp having a sealed-in
bulb, a lamp shall meet the applicable require-
ments of this standard when tested with a bulb
whose filament is positioned within ± .010 inch of
the nominal design position specified in SAE
Standard J573d, Lamp Bulbs and Sealed Units,
December 1968, or specified by the bulb manufac-
turer.

55.1.1.18 A backup lamp is not required to meet
the minimum photometric values at each test point
specified in Table I of SAE Standard J593c,
Backup Lamps, February 1968 if the sum of the
candlepower measured at the test points within
each group listed in Figure 2 is not less than the
group totals specified in that figure.

(a) Each headlamp system, other than a
headlamp system designed to conform to para-
graph S7.5, that is designed to use such external
aiming devices shall not deviate more than 0.30
degree when a downward torque of 201b.-in. (2.25
N-m) is applied to the headlamp in its normal
operating position, through the lamp's mechanical
axis at the plane of the forwardmost aiming pad.
Each headlamp system that is designed to con-
form to paragraph S7.5 and that is designed to
use such external aiming devices, and which is
manufactured on or after September 1, 1990, shall
comply with this paragraph.

55.1.1.19 Each variable load turn signal flasher
shall comply with voltage drop and durability
requirements of SAE Standard J590b, Turn Signal
Flasher, October 1965 with the maximum design
load connected, and shall comply with starting
time, flash rate, and percent current "on" time

(Rev. 5/15/90)

PART 571; S 108-4

requirements of J590b both with the minimum and
with the maximum design load connected.

55.1.1.20 The lowest voltage drop for turn signal
flashers and hazard warning signal flashers meas-
ured between the input and load terminals shall
not exceed 0.8 voU.

55.1.1.21 A motor-driven cycle whose speed
attainable in 1 mile is 30 mph or less need not be
equipped with turn signal lamps.

55.1.1.22 A motor-driven cycle whose speed
attainable in 1 mile is 30 mph or less may be
equipped with a stop lamp whose effective pro-
jected luminous lens area is not less than 3'/2
square inches and whose photometric output for
the groups of test points specified in Figure 1 is
at least one-half of the minimum values set forth
in that figure.

55.1.1.23 Each tail lamp manufactured to replace
the tail lamp designed to conform to SAE Stand-
ard J585d, Tail Lamps, August 1970, may also be
designed to conform to J585d.

55.1.1.24 Each turn signal lamp manufactured to
replace a turn signal lamp (on a motorcycle) that
was designed to conform to SAE Standard J588d,
Turn Signal Lamps, June 1966, may also be
designed to conform to J588d.

55.1.1.25 Each turn signal lamp on a motorcycle
manufactured on and after January 1, 1973, shall
have an effective projected luminous area of not
less than V/i square inches.

55.1.1.26 Note 6 of Table 1 in SAE Standard
J588e, Tiini Signal Lamps, September 1970. does
not apply. [A stop lamp that is not optically com-
bined, as defined by SAE Information Report J387
Terminology — Motor Vehicle Lighting NOV 87,
with a turn signal lamp shall remain activated
when the turn signal is flashing. (56 F.R. 26343 —
June 7, 1991. Effective: July 8, 1991.)]

55.1.1.27 (a) Except as provided in paragraph (b)
of this section, each passenger car manufactured
on or after September 1, 1985, and each multipur-
pose passenger vehicle, truck, and bus whose
overall width is less than 80 inches, whose
GVWR is 10,000 pounds or less, manufactured on

or after September 1, 1993, shall be equipped with
a high-mounted stop lamp which:

(1) Shall have an effective projected lumi-
nous area not less than AV2 square inches.

(2) Shall have a signal visible to the rear
through a horizontal angle from 45 degrees to the
left to 45 degrees to the right of the longitudinal
axis of the vehicle.

(3) Shall have the minimum photometric val-
ues in the amount and location listed in Figure
10.

(4) Need not meet the requirements of para-
graphs 3.1.6 Moisture Test, 3.1.7 Dust Test, and
3.1.8 Corrosion Test of SAE Recommended Prac-
tice J 186a if it is mounted inside the vehicle.

(5) Shall provide access for convenient
replacement of the bulb without the use of special
tools.

(b) Each multipurpose passenger vehicle, truck
and bus whose overall width is less than 80
inches, whose GVWR is 10,000 pounds or less,
whose vertical centerline, when the vehicle is
viewed from the rear, is not located on a fixed
body panel but separates one or two movable
body sections, such as doors, which lacks suffi-
cient space to install a single high-mounted stop
lamp on the centerline above such body sections,
and which is manufactured on or after September
1, 1993, shall have two high-mounted stop lamps
which:

(1) Are identical in size and shape and have
an effective projected luminous area not less than
2 '74 inches each.

(2) Together have a signal to the rear visible
as specified in paragraph (a)(2) of this section.

(3) Together have the minimum photometric
values specified in paragraph (a)(3) of this sec-
tion.

(4) Shall provide access for convenient
replacement of the bulbs without special tools.

[S5.1.1.28 A multipurpose passenger vehicle,
truck, or bus, whose overall width is less than 80
inches, and whose GVWR is 10,000 pounds or
less, that is manufactured between September 1,
1992 and September 1, 1993, may be equipped
with a high-mounted stop lamp or, in the case of
vehicles subject to S5. 1.1. 27(b), two high-mounted
stop lamps, that conform to S5.1.1.27 and
S5.3.1.8. (56 F.R. 16015— April 19, 1991. Effective:
Optional compliance, September 1, 1992; Manda-
tory compliance, September 1, 1993)J

PART 571: S 108-5

(Rev. 6/7/91)

55.1.1.29 Instead of the headlamps specified by
Table III, a motorcycle may be equipped with one
half of any headlighting system specified in S7
which provides both a full upper beam and full
lower beam, and where more than one lamp must
be used, the lamps shall be mounted vertically,
with the lower beam as high as practicable. When
installed on a motorcycle such half system need
not meet the aiming requirements specified in S7.

55.1.1.30 Each replaceable bulb headlamp that is
designed to meet the photometric requirements of
SAE Recommended Practice J584, Motorcycle
Headlamps, April 1964, and that is equipped with
a light source other than a standardized replace-
able light source, and that is manufactured on or
after September 1, 1990 shall have the word
"motorcycle" permanently marked on the lens in
characters not less than 0.114 inch (3mm) in
height.

55.1 .1 .31 On a motor vehicle whose overall width
is less than 80 inches:

(a) The functional lighted lens area of a single
compartment stop lamp, and a single compartment
rear turn signal lamp, shall be not less than 50
square centimeters.

(b) If a multiple compartment lamp or multiple
lamps are used to meet the photometric require-
ments for stop lamps and rear turn signal lamps,
the functional lighted lens area of each compart-
ment or lamp shall be at least 22 square centi-
meters, provided the combined area is at least 50
square centimeters.

55.1.1.32 On a motor vehicle, except a passenger
car, whose overall width is 80 inches or more,
measurements of the functional lighted lens area,
and of the photometries, of a multiple compart-
ment stop lamp, and a multiple compartment turn
signal lamp, shall be made for the entire lamp and
not for the individual compartments.

S5.1.2 Plastic materials used for optical parts such
as lenses and reflectors shall conform to SAE Rec-
ommended Practice J576c, May 1970, except that:

(a) Plastic lenses used for inner lenses or those
covered by another material and not exposed
directly to sunlight shall meet the requirements of
paragraphs 3.4 and 4.2 of SAE J576c. when cov-
ered by the outer lens or other material;

(b) After the outdoor-exposure test, the haze
and loss of surface luster of plastic materials used

for lamp lenses shall not be greater than 30 per-
cent haze as measured by ASTM- 1 003-6 1 , Haze ^
cmd Luminous Transmittance of Transparent Plas- (
tic; and

(c) After the outdoor exposure test, plastic
materials used for reflex reflectors shall meet the
appearance requirements of paragraph 4.2.2 of
SAE J576c.

55.1.3 No additional lamp, reflective device, or
other motor vehicle equipment shall be installed
that impairs the effectiveness of lighting equip-
ment required by this standard.

55.1.4 Each school bus shall be equipped with a
system of either:

(a) Four red signal lamps designed to conform
to SAE Standard J887, School Bus Red Signal
Lamps, July 1964, and installed in accordance
with that standard; or

(b) Four red signal lamps designed to conform
to SAE Standard J887, School Bus Red Signal
Lamps, July 1964, and four amber signal lamps
designed to conform to that standard, except for
their color, and except that their candlepower
shall be at least 2'/2 times that specified for red "^
signal lamps. Both red and amber lamps shall be
installed in accordance with SAE Standard J887,
except that:

(i) Each amber signal lamp shall be located
near each red signal lamp, at the same level, but
closer to the vertical centerline of the bus; and

(ii) The system shall be wired so that the
amber signal lamps are activated only by manual
or foot operation, and if activated, are automati-
cally deactivated and the red signal lamps auto-
matically activated when the bus entrance door is
opened.

55.1.5 The color in all lamps, reflective devices,
and associated equipment to which this standard
applies shall comply with SAE Standard J578c,
Color Specification for Electric Signal Lighting
Devices, February 1977.

S5.2. Other requirements.

S5.2.1 The words "it is recommended that,"
"recommendations," or "should be" appearing in
any SAE Standard or Recommended Practice ref- f^
erenced or subreferenced in this standard shall be ^
read as setting forth mandatory requirements.

(Rev. 7/19/89)

PARI' 571; S 108-6

except that the aiming pads on the lens face and
the blacl: area surrounding the signal lamp, rec-
ommended in SAE Standard J887, School Bus Red
Signal Lamps, July 1964, are not required.

S5.2.2 The words "Type 1 (SW)," 'Type 2
(53/4")," "Type 2 (7")," "Type lA," "Type
2A," and "Type 2B" appearing in any SAE
Standard or Recommended Practice referenced or
subreferenced in this standard shall also be read as
setting forth requirements respectively for the fol-
lowing types of headlamps: ICl, 2C1, 2D1, lAl,
2A1, and2BI.

S5.3 Location of required equipment.

5.3.1 Except as provided in succeeding paragraphs
of S5.3.1 [and S7] each lamp, reflective device,
and item of associated equipment shall be securely
mounted on a rigid part of the vehicle other than
glazing that is not designed to be removed except
for repair, in accordance with the requirements of
Tables I or III [as applicable, and S7, and in the
location] specified in Table II (multipurpose pas-
senger vehicles, trucks, trailers, and buses 80 or
more inches in overall width) and Table IV (all
passenger cars, and motorcycles, and multipurpose
passenger vehicles, trucks, trailers, and buses less
than 80 inches in overall width), as applicable. (54
F.R. 30223— July 19, 1989. Effective: July 19, 1989.)

S5.3.1.1 Except as provided in S5. 3. I.I.I, each
lamp and reflective device shall be located so that
it meets the visibility requirements specified in
any applicable SAE Standard or Recommended
Practice. In addition, no part of the vehicle shall
prevent a parking lamp, taillamp, stop lamp, turn-
signal lamp, or backup lamp from meeting its
photometric output at any applicable group of test
points specified in Figures Ic and 2, or prevent
any other lamp from meeting the photometric out-
put at any test point specified in any applicable
SAE Standard or Recommended Practice. How-
ever, if motor vehicle equipment (e.g., mirrors,
snow plows, wrecker booms, backhoes, and
winches) prevents compliance with this paragraph
by any required lamp or reflective devices, an
auxiliary lamp or device meeting the requirements
of this paragraph shall be provided.

S5.3.1.1.1 Clearance lamps may be mounted at a
location other than on the front and rear if nec-
essary to indicate the overall width of a vehicle.

or for protection from damage during normal
operation of the vehicle, and at such a location
they need not be visible at 45 degrees inboard.

55.3.1.2 On a truck tractor, the red rear reflex
reflectors may be mounted on the back of the cab,
at a minimum height not less than 4 inches above
the height of the rear tires.

55.3.1.3 On a trailer, the amber front side reflex
reflectors and amber front side-marker lamps may
be located as far forward as practicable exclusive
of the trailer tongue.

55.3.1.4 When the rear identification lamps are
mounted at the extreme height of a vehicle, rear
clearance lamps need not meet the requirement of
Table II that they be located as close as prac-
ticable to the top of the vehicle.

55.3.1.5 The center of the lens referred to in SAE
Standard J593c. Backup Lamps, February 1968, is
the optical center.

55.3.1.6 On a truck tractor, clearance lamps
mounted on the cab may be located to indicate the
width of the cab, rather than the overall width of
the vehicle.

55.3.1.7 On a motor vehicle on which the front
turn signal lamp is less than 100 mm from the
lighted edge of a lower beam headlamp, as meas-
ured from the optical center of the turn signal
lamp, the multiplier applied to obtain the required
minimum luminous intensities shall be 2.5.

55.3.1.8 [(a) Each high-mounted stop lamp
installed in or on a vehicle subject to S5. 1.1. 27(a)
shall be located as follows:

(1) With its center at any place on the verti-
cal centerline of the vehicle, including the glaz-
ing, as the vehicle is viewed from the rear.

(2) If the lamp is mounted below the rear
window, no portion of the lens shall be lower
than 6 inches below the rear window on
convertibles, or 3 inches on other passenger cars.

(3) If the lamp is mounted inside the vehicle,
means shall be provided to minimize reflections
from the light of the lamp upon the rear window
glazing that might be visible to the driver when
viewed directly, or indirectly in the rearview mir-
ror.

PART 571; S 108-7

(Rev. 7/19/89)

(b) The high-mounted stop lamps installed in or
on a vehicle subject to S5. 1.1. 27(b) shall be
located at the same height, with one vertical edge
of each lamp on the vertical edge of the body sec-
tion nearest the vertical centerline.

(6) In the second column Table III for the
item "High-mounted stop lamp", the text "1 red,
for passenger cars only" is revised to read "1
red".

(7) In the second column of Table IV for the
item "High-mounted stop lamp", the text "On
the rear, on the vertical centerline (See S4.3.1.8),
effective September 1, 1985, for passenger cars
only" is revised to read "On the rear, on the ver-
tical centerline (See S5.1.1.27, S5.3.1.8, and
Table III)."

(8) In the fourth column of Table IV for the
item "High-mounted stop lamp", the text "(See
S4.3.I.8)" is revised to read "See S5.3.1.8 for
passenger cars. Not less than 34 inches for multi-
purpose passenger vehicles, trucks, and buses."
(56 F.R. 16015— April 19, 1991. Effective: Optional
compliance, September 1, 1992; Mandatory compli-
ance September 1, 1993)]

55.4 Equipment combinations. Two or more
lamps, reflective devices, or items of associated
equipment may be combined if the requirements
for each lamp, reflective device, and item of asso-
ciated equipment are met, with the following
exceptions:

(a) No high-mounted stop lamp shall be com-
bined with any other lamp or reflective device,
other than with a cargo lamp.

(b) No high-mounted stop lamp shall be com-
bined optically, as defined by SAE Information
Report J387 Terminology — Motor Vehicle Light-
ing NOV 87, with any cargo lamp.

(c) No clearance lamp shall be combined opti-
cally, as defined by SAE Information Report J387
Terminology — Motor Vehicle Lighting NOV 87,
with any tail lamp.

S5.4.1 Removed.

(55 F.R. 46669 November 6, 1990.)

55.5 Special wiring requirements.

S5.5.1 Each vehicle shall have a means of switch-
ing between lower and upper beams that conforms
to SAE Recommended Practice J564a, Headlamp
Beam Switching. April 1964, or to SAE Rec-

ommended Practice J565b, Semi-Aittomatic
Headlamp Beam Switching Devices, February
1969. Except as provided in S5.5.8, the lower and ^-
upper beams shall not be energized simultaneously (
except momentarily for temporary signalling pur-
poses or during switching between beams.

55.5.2 Each vehicle shall have a means for
indicating to the driver when the upper beams of
the headlamps are on that conforms to SAE Rec-
ommended Practice J564a, April 1964, except that
the signal color need not be red.

55.5.3 The taillamps on each vehicle shall be acti-
vated when the headlamps are activated in a
steady-burning state.

55.5.4 The stoplamps on each vehicle shall be
activated upon application of the service brakes.
The high-mounted stoplamp on each passenger car
shall be activated only upon application of the
service brakes.

55.5.5 The vehicular-hazard warning-signal
operating unit on each vehicle shall operate
independently of the ignition or equivalent switch,

and when activated, shall cause to flash simulta- ^

neously sufficient turn signal lamps to meet, as a J^

minimum, the turn signal lamp photometric ^?"
requirements of this standard.

55.5.6 Each vehicle equipped with a turn signal
operating unit shall also have an illuminated pilot
indicator. Failure of one or more turn signal lamps
to operate shall be indicated in accordance with
SAE Standard J588e, Turn Signal Lamps, Septem-
ber 1970, except when a variable-load turn signal
flasher is used on a truck, bus, or multipurpose
passenger vehicle 80 or more inches in overall
width, on a truck that is capable of accommodat-
ing a slide-in camper, or on any vehicle equipped
to tow trailers.

55.5.7 On each passenger car. and motorcycle,
and multipurpose passenger vehicle, truck, and
bus of less than 80 inches overall width:

(a) When the parking lamps are activated, the
taillamps, license plate lamps, and side marker
lamps shall also be activated; and

(b) When the headlamps are activated in a
steady-burning state, the taillamps, parking lamps. __^
license plate lamps and side marker lamps shall I
also be activated. ^

(Rev. 4/19/91)

PART 571; S 108-8

55.5.8 On a motor vehicle equipped with a
^ headhghting system designed to conform to the
B photometric requirements of Figure 15, the lamps

marked "L" or "LF'" may be wired to remain
permanently activated when the lamps marked
"U" or "LF" are activated. On a motor equipped
with an Integral Beam headhghting system meet-
ing the photometric requirements of section
S7.4(a)(l)(ii), the lower beam headlamps shall be
wired to remain permanently activated when the
upper beam headlamps are activated. On a motor
vehicle equipped with a headhghting system
designed to conform to the requirements of Figure
17, a lower beam light source may be wired to
remain activated when an upper beam light source
is activated if the lower beam light source contrib-
utes to compliance of the headhghting system with
the upper beam requirements of Figure 17.

55.5.9 Except as provided in Section S5.5.8, the
wiring harness or connector assembly of each
headlamp system shall be designed so that only
those light sources intended for meeting lower
beam photometries are energized when the beam

^ selector switch is in the lower beam position, and

^ that only those light sources intended for meeting
^ upper beam photometries are energized when the
beam selector switch is in the upper beam posi-
tion.

55.5.10 The wiring requirements for lighting
equipment in use are:

(a) Turn signal lamps, hazard warning signal
lamps, and school bus warning lamps shall be
wired to flash;

(b) Headlamps and side-marker lamps may be
wired to flash for signalling purposes;

(c) A motorcycle headlamp may be wired to
allow either its upper beam or its lower beam, but
not both, to modulate from a higher intensity to
a lower intensity in accordance with Section S4.6;

(d) All other lamps shall be wired to be steady-
burning.

S5.6 Motorcycle headlamp modulation sys-
tem.

S5.6.1 A headlamp on a motorcycle may be wired
m to modulate either the upper beam or the lower

" beam from its maximum intensity to a lesser

intensity provided that:

(a) The rate of modulation shall be 240 ± 40
cycles per minute.

(b) The headlamp shall be operated at maxi-
mum power for 50 to 70 percent of each cycle.

(c) The lowest intensity at any test point shall
be not less than 17 percent of the maximum
intensity measured at the same point.

(d) The modulator switch shall be wired in the
power lead of the beam filament being modulated
and not in the ground side of the circuit.

(e) Means shall be provided so that both the
lower beam and upper beam remain operable in
the event of a modulator failure.

(f) The system shall include a sensor mounted
with the axis of its sensing element perpendicular
to a horizontal plane. Headlamp modulation shall
cease whenever the level of light emitted by a
tungsten filament light operating at 3000° Kelvin
is either less than 270 lux (25 footcandles) of
direct light for upward pointing sensors or less
than 60 lux (5.6 footcandles) of reflected light for
downward pointing sensors. The light is measured
by a silicon cell type light meter that is located
at the sensor and pointing in the same direction
as the sensor. A Kodak Gray Card (Kodak R-27)
is placed at ground level to simulate the road sur-
face in testing downward-pointing sensors.

(g) When tested in accordance with the test
profile shown in Figure 9, the voltage drop across
the modulator when the lamp is on at all test
conditions for 12-volt systems and 6- volt systems
shall not be greater than .45 volt. The modulator
shall meet all the provisions of the standard after
completion of the test profile shown in Figure 9.

(h) Means shall be provided so that both the
lower and upper beam function at design voltage
when the headlamp control switch is in either the
lower or upper beam position when the modulator
is off.

S5.6.2 (a) Each motorcycle headlamp modulator
not intended as original equipment, or its con-
tainer, shall be labeled with the maximum watt-
age, and the minimum wattage, appropriate for its
use. Additionally, each such modulator shall com-
ply with S5.6.1 (a) through (g) when connected to
a headlamp of the maximum rated power and a
headlamp of the minimum rated power and shall
provide means so that the modulated beam func-
tions at design voltage when the modulator is off.
(b) Instructions, with a diagram, shall be pro-
vided for mounting the light sensor including

PART 571; S

location on the motorcycle, distance above the
road surface, and orientation with respect to the
light.

[S5.7 Conspicuity Systems. Each trailer of 80
or more inches overall width, and with a GVWR
over 10,000 lbs., manufactured on or after Decem-
ber 1, 1993, except a trailer designed exclusively
for living or office use, shall be equipped with
either retroreflective sheeting that meets the
requirements of S5.7.1, reflex reflectors that meet
the requirements of S5.7.2, or a combination of
retroreflective sheeting and reflex reflectors that
meet the requirement of S5.7.3.

[S5.7.1 Retroreflective sheeting. Each trailer
to which S5.7 applies that does not conform to
S5.7.2 or S5.7.3 shall be equipped with
retroreflective sheeting that confoiTns to the
requirements specified in S5.7.1.1 through
S5.7.1.5.

[S5.7.1.1 Construction. Retroreflective sheeting
shall consist of a smooth, flat, transparent exterior
film with retroreflective elements embedded or
suspended beneath the film so as to form a non-
exposed retroreflective optical system.

[S5.7.1.2 Performance requirements. Retro-
reflective sheeting shall meet the requirements of
ASTM D 4956-90, Standard Specification for
Retroreflective Sheeting for Traffic Control, for
Type V Sheeting, except for the photometric
requirements, and shall meet the minimum photo-
metric performance requirements specified in Fig-
ure 29.

[5.7.1.3 Sheeting pattern, dimensions, and
relative coefficients of retroref lection.

(a) Retroreflective sheeting shall be applied in
a pattern of alternating white and red color seg-
ments to the side and rear of each trailer, and in
white to the upper rear comers of each trailer, in
the locations specified in S5.7.1.4, and illustrated
in Figure 30.

(b) Except for a segment that is trimmed to
clear obstructions, or lengthened to provide red
sheeting near red lamps, each white or red seg-
ment shall be a length of 300 mm ± 1 50 mm.

(c) Neither white nor red sheeting shall rep-
resent more than two thirds of the aggregate of
any continuous strip marking the width of a

trailer, or any continuous or broken strip marking

its length. _

(d) Retroreflective sheeting shall have a width (
of 50 mm (Grade D0T-C2), 75 mm (Grade
D0T-C3), or 100 mm (Grade D0T-C4).

(e) The coefficients for retroreflection of each
segment of red or white sheeting shall be not less
than the minimum values specified in Figure 29
of this standard for grades D0T-C2, D0T-C3,
and DOT-C4.

[S5.7.1.4 Location, (a) Retroreflective sheeting
shall be applied to each trailer on the side and rear
as specified below, but need not be applied to dis-
continuous surfaces such as outside ribs, stake
post pickets on platform trailers, and external
protruding beams, or to items of equipment such
as door hinges and lamp bodies.

(b) The edge of white sheeting shall not be
located closer than 75 mm to the edge of the
luminous lens area of any lamp that is required
by this standard.

(c) The edge of red sheeting shall not be
located closer than 75 mm to the edge of the
luminous lens area of any amber lamp that is
required by this standard. /"^

[S5.7.1.4.1 Rear. Retroreflective sheeting shall
be applied to the rear of each trailer as follows:

(a) Element 1: a horizontal strip of sheeting in
alternating colors across the full width of the
trailer as close to the extreme edges as prac-
ticable, and as close as practicable to 1.25 meters
above the road surface.

(b) Element 2: two pairs of white strips of
sheeting, each pair consisting of strips 300 mm
long of grade D0T-C2 (50 mm wide), D0T-C3
(75 mm wide), or DOT-C4 (100 mm wide),
applied horizontally and vertically to the right and
left upper contours of the body, as viewed from
the rear, as close to the top of the trailer and as
far apart as practicable.

(c) Element 3: a strip of sheeting in alternating
colors across the full width of the horizontal
member of the rear underride protection device.

[S5.7.1.4.2 Side. Retroreflective sheeting shall
be applied to each side of a trailer as follows:

(a) A horizontal strip of sheeting in alternating
colors, originating and terminating as close to the /^
front and rear ends as practicable, and as close as ^^
practicable to 1.25 m above the road surface

(Rev. 12/10/92)

PART 5''1; S 108-10

except that, at the location chosen, the strip shall
not be obscured in whole or in part by other
^k motor vehicle equipment or trailer cargo. The
^r strip need not be continuous as long as not less
than half of the length of the trailer is covered
and the spaces are distributed as evenly as prac-
ticable.

(b) If necessary to clear rivet heads or other
similar obstructions, grade D0T-C2 retro-
reflective sheeting may be separated into two 25
mm wide strips of the same length and color,
separated by a space of not more than 25 mm,
and used in place of the retroreflective sheeting
that would otherwise be applied.

[S5.7.1.5 Certification. The letters DOT-C2.
D0T-C3, or D0T-C4, as appropriate, constituting
a certification that the retroreflective sheeting con-
forms to the requirements of S5.7.1.2, shall appear
at least once on the exposed surface of each white
or red segment of retroreflective sheeting, and at
least once every 300 mm on retroreflective sheet-
ing that is white only. The characters shall be not
less than 3 mm high, and shall be permanently
stamped, etched, molded, or printed in indelible
^ ink.

" IS5.7.2 Reflex Reflectors. Each trailer to which
S5.7 applies that does not conform to S5.7.1 or
S5.7.3 shall be equipped with reflex reflectors in
accordance with this section.

[S5.7.2.1(a) Each reflex reflector shall conform to
SAE Standard J594f, Reflex Reflectors, January
1977.

[S5.7.2.2 Reflex reflectors shall be installed
and located as specified below:

^ (a) In the same locations and in the same

m length in which retroreflective sheeting is required

by S5.7.1.4 to be applied in alternating colors,
reflex reflectors shall be installed in a repetitive
pattern of two or three white reflex reflectors
alternating with two or three red reflex reflectors,
with the center of each reflector not more than
100 mm from the center of each adjacent reflec-
tor.

(b) In the same locations and in the same
length in which white retroreflective sheeting is
required by S5.7.1.4 to be installed, white reflex
reflectors shall be installed, with the center of
each white reflex reflector not more than 100 mm
from the center of each adjacent reflector.

[S5.7.2.3 Certification. The exposed surface of
each reflex reflector shall be marked with the let-
ters DOT-C which constitutes a certification that
the reflector conforms to all applicable require-
ments of section 571.108 of this part. The certifi-
cation shall be not less than 3 mm high, and
permanently stamped, etched, molded or printed in
indelible ink.

[S5.7.3 Combination of sheeting and reflec-
tors. Each trailer to which S5.7 applies that does
not conform to S5.7.1 or S5.7.2, shall be equipped
with retroreflective materials that meet the
requirements of S5.7.1 except that reflex reflectors
that meet the requirements of S5.7.2.1, and that
are installed in accordance with S5.7.2.2, may be
used instead of any corresponding element of
retroreflective sheeting located as required by
S5.7.1.4. (F.R. 58406— December 10, 1992. Effec-
tive: December 1, 1993)]

S5.8 Replacement equipment.

55.8.1 Each lamp, reflective device, or item of
associated equipment manufactured to replace any
lamp, reflective device, or item of associated
equipment on any vehicle to which this standard
applies, shall be designed to confonn with this
standard.

55.8.2 Unless otherwise specified in this standard,
each lamp, reflective device, or item of associated
equipment to which section S5.7.1 applies may be
labeled with the symbol DOT, which shall con-
stitute a certification that it conforms to applicable
Federal motor vehicle safety standards.

PART 571; S 108-11

(Rev. 12/10/92)

56 Subreferenced SAE Standards and Rec-
ommended Practices.

56.1 SAE Standards and Recommended Practices
subreferenced by the SAE Standards and Rec-
ommended Practices included in Tables I and III
and paragraphs S5.1.4 and S5.5.1 are those pub-
lished in the 1970 edition of the SAE Handbook,
except that the SAE standard referred to as
"J575" is J575e, Tests for Motor Vehicle Lighting
Devices and Components, August 1970, for
stoplamps, designed to conform to SAE Standards
J586c, J586 FEB 84, and J 1398 MAY 85; for
taillamps designed to conform to SAE Standards
J585d and J585e; for turn signal lamps designed
to conform to SAE Standards J588e. J588 NOV
84, and J 1395 APR 85; and for high-mounted
stoplamps designed to conform to SAE Rec-
ommended Practice J 186a. The reference in J585e
to J256 does not apply. For headlamps, unless
otherwise specified in this standard, the version of
SAE Standard J575 is DEC 88, and the version of
SAE Standard J602 is OCT 80. The definition of
"optically combined" in SAE Information Report
J387 Terminology — Motor Vehicle Lighting NOV
87, applies to that term as used in J586c and
J588e.

56.2 Requirements of SAE Standards incorporated
by reference in this standard, other than J576b and
J576c, do not include tests for warpage of devices
with plastic lenses.

56.3 The term "effective projected luminous lens
area" has the same meaning as the term "func-
tional lighted lens area" in any SAE Standard or
Recommended Practice incorporated by reference
or by subreference in this standard.

57 Headlighting requirements.

57.1 Each passenger car, multipurpose passenger
vehicle, truck, and bus shall be equipped with a
headlighting system designed to conform to the
requirements of S7.3, S7.4, or S7.5.

57.2 (a) The lens of each original and replacement
equipment headlamp, and of each original equip-
ment and replacement equipment beam contributor
manufactured on or after December 1, 1989, shall
be marked with the symbol "DOT," either hori-
zontally or vertically which shall constitute the
certification required by 15 U.S.C. 1403.

(b) The lens of each headlamp and of each
beam contributor manufactured on or after
December 1, 1989, to which paragraph (a) of this —
section applies shall be marked with the name V
and/or trademark registered with the U.S. Patent

and Trademark Office of the manufacturer of
such headlamp or beam contributor, or its
importer, or any manufacturer of a vehicle
equipped with such headlamp or beam contribu-
tor. Nothing in this paragraph shall be construed
to authorize the marking of any such name and/
or trademark by one who is not the owner, unless
the owner has consented to it.

(c) Each headlamp and beam contributor to
which paragraph (a) of this section applies shall
be marked with its voltage and with its part or
trade number.

S7.3 Sealed beam headlighting system. A

sealed beam headlighting system shall be designed
to meet the requirements of one of the following
subparagraphs of S7.3.2 through S7.3.9. In ref-
erences to Figures in SAE J 1383 APR 85 for
headlamp dimensional requirements, only those
dimensions marked "I" for interchangeability are
applicable.

57.3.1 The lens of each sealed beam headlamp ^
designed to conform to S7.3.2 through S7.3.6 shall

be marked according to paragraph 5.4.3 through
5.4.5 of SAE Standard J 1383 April 85 Perform-
ance Requirements for Motor Vehicle Headlamps.

57.3.2 Type A headlighting system. A Type A
headlighting system consists of two Type 1 Al and
two Type 2A1 headlamps and associated hard-
ware, which are designed to conform to the fol-
lowing requirements:

(a) SAE Standard J 1383 APR 85 Performance
Requirements for Motor Vehicle Headlamps, with
the following exceptions:

(1) Paragraphs 1, 2.1.2, 2.8.2, 3, 4.1.1, 4.1.2,
4.1.3, 4.4, 4.6, 4.8 through 4.18, 5.1.1, 5.1.3,
5.1.5, 5.1.7 through 5.1.16. 5.2.2, 5.3.5, 5.4.1,
5.4.2, and 6 through 6.4 do not apply.

(2) In paragraph 5.3.2, the words "and
retaining rings" are omitted.

(3) In paragraphs 4.5.2 and 5.1.6, the words
"either Table 1 or Table 2 of SAE J579 DEC 84

as appropriate" are substituted for "Table 3." a

(b) SAE Standard J580 DEC 86 Sealed Beam (
Headlamp Assembly (except paragraphs 3, 4.1.1,

PART 571; S 108-12

5.1.1.1, 5.1.2.3, and the second sentence of 5.1.6);
^ in 5.2.1, delete the words "and retaining rings;"

^^ the correct reference is SAE J 1383 Figure 6, 9, 12
^ and 14.

(c) After a vibration test conducted in accord-
ance with paragraph S8.8, there shall be no evi-
dence of loose or broken parts, other than fila-
ments, visible without magnification.

(d) The maximum wattage at 12.8 volts (design
voltage): Single filament headlamp, 55 watts on
the upper beam; dual filament headlamp, 43 watts
on the upper beam and 65 watts on the lower
beam.

S7.3.3 Type B headlighting system. A Type B
headlighting system consists of two Type 2B1
headlamps and associated hardware, which are
designed to conform to the following require-
ments:

(a) The requirements of paiagraphs S7.3.2(a)
through (c).

(b) The maximum wattage at 12.8 volts (design
voltage): 70 watts on the upper beam and 60
watts on the lower beam.

^ S7.3.4 Type C headlighting system. A Type C

H headlighting system consists of two Type ICl and
two Type 2C1 headlamps and associated hard-
ware, which are designed to conform to the
requirements of paragraph S7.3.2(a) through (d).

57.3.5 Type D headlighting system, (a) A

Type D headlighting system consists of two Type
2D1 headlamps and associated hardware, which
are designed to conform to the requirements of
paragraph S7.3.2(a) through (c).

[(b) The maximum wattage at 12.8 volts
(design voltage): 65 watts on upper beam, and 55
watts on lower beam. (55 F.R. 4424 — February 8,
1990. Effective: March 12, 1990.)]

57.3.6 Type E headlighting system, (a) A

Type E headlighting system consists of two Type
2E1 headlamps and associated hardware, which
are designed to conform to the requirements of
paragraph S7.3.2(a) through (c).

[(b) The maximum wattage at 12.8 vohs
(design voltage): 70 watts on upper beam, and 60
watts on lower beam. (55 F.R. 4424 — February 8,
^ 1990. Effective: March 12, 1990.)]

" S7.3.7 Type F headlighting system. A Type F

headlighting system consists of two Type UP and

two Type LP headlamps and associated hardware,
which are designed to conform to the following
requirements:

(a) Figures 11, 12, 13, and 14 as appropriate.

(b) The photometric requirements of Figure 15
of this standard. A realm tolerance of ± V4 degree
is allowed for any test point on the Type LF lamp
when tested alone, but is not allowed on the Type
UF lamp when tested alone. For the test point
10U-90U, measurement shall be from the nor-
mally exposed surface of the lens face.

(c) SAE Standard J 1383 APR 85 Performance
Requirements for Motor Vehicle Headlamps, Sec-
tions 2.4, 2.5, 2.6, 4.1, 4.1.4 and [5.1.4].

(d) When tested in accordance with section (c),
the mounted assembly (either Type UP or Type
LF headlamps, respective mounting ring, aiming
ring, and aim adjustment mechanism) shall be
designed to conform to the requirements of Figure
15 for upper or lower beams respectively without
realm when any conforming Type UF or LF
headlamp is tested and replaced by another
conforming headlamp of the same Type.

(e) SAE J580 DEC 86 Sealed Beam Headlamp
Assembly with the following exceptions:

(1) Section 2.2 Mounting Ring reads: "the
adjustable ring upon which the sealed beam unit
is mounted and which forces the sealed beam unit
to seat against the aiming ring when assembled
into a sealed beam assembly."

(2) The definition "2.3 Aiming Ring" reads:
"The clamping ring that retains the sealed beam
unit against the mounting ring, and that provides
an interface between the unit's aiming/seating
pads and the headlamp aimer adapter (locating
plate)."

(3) Section 4.1.1 Vibration Test does not
apply.

(4) Section 5.1.1.1 [and 5.1.2.3] do not
apply.

(5) Section 5.1.2.1 reads: "When the
headlamp assembly is tested in the laboratory, a
minimum aiming adjustment of ± 2.5 degrees
shall be provided in the horizontal plane and ± 4
degrees in the vertical plane."

(6) Section 5.1.2.2 concludes: "... through
an angle of ± 2.5 degrees and ± 4 degrees respec-
tively."

(7) Section 5.1.6 is retitled "Retaining Ring/
Aiming Ring Tests." The phrase "92 x
150mm . . . 0.340 in (8.6 mm)" is added at the

PART 571; S 1(

(Rev. 2/8/90)

end of the table for flange thickness. The sentence
beginning 'The fastening means" is deleted. (55
F.R. 4424— February 8, 1990. Effective: March 12,
1990)]

(8) Figures 2, 3, and 4 do not apply, and the
reference to them in section 4.5 is replaced by
"Figure 16, Deflectometer, of Federal Motor
Vehicle Safety Standard No. 108."

(f) A lens for a Type F headlamp incorporating
an upper beam shall be labeled "UF". A lens for
a Type F headlamp incorporating a lower beam
shall be labeled "LF". The face of letters, num-
bers, or other symbols molded on the surface of
the lens shall not be raised more than 0.020 in.
(0.5 mm), and shall be placed no closer to the
geometric center of the lens than 1.375 in (35
mm). The marking shall be molded in the lens
and shall be not less than Va in. (6.35 mm.) in
size.

(g) The maximum wattage at 12.8 volts (design
voltage): 70 watts on the upper beam and 60
watts on the lower beam.

(h) Type F headlamps may be mounted on
common or parallel seating and aiming planes to
permit simultaneous aiming of both headlamps
provided that when tested with any conforming
Type UF and LF headlamps according to Section
SIO:

(1) The assembly (consisting of the Type UF
and LF headlamps, mounting rings, the aiming/
seating rings, and aim adjustment mechanism),
shall be designed to conform to the test point val-
ues of Figure 15.

(2) There shall be no provision for adjust-
ment between the common or parallel aiming and
seating planes of the two lamps.

(i) After a vibration test conducted in
accordance with paragraph S8.8, the Type F
system shall show no evidence of loose or bro-
ken parts, other than filaments, visible without
magnification.

S7.3.8 Type G headlighting system. A Type G
headlamp system consists of two Type IGl
headlamps and two Type 20 1 headlamps each of
which is designed to conform to the following
requirements:

(a) Figures 1 8 and 2 1 .

(b) SAE Standard J 1383 APR 85 Performance
Requirements for Motor Vehicle Headlamps
(except paragraphs 1, 2.1.2, 2.8.2, 3, 4.1.1, 4.1.2,
4.1.3, 4.4, 4.6, 4.8 through 4.18, 5.1.1, 5.1.3,

5.1.5 through 5.1.16, 5.2.2, 5.3.5 through 6.4). In
paragraph 5.3.2 the words "and retaining rings"

are omitted. In paragraph 4.5.2, the words either i"
Table 1 or Table 2 or SAE J579 DEC 84. as ^
appropriate" are substituted for the words "Table
3."

(1) Sections 2.2, 2.3, 4.1.1, 5.1.1.1, 5.1.2.3,

5.1.6 and 5.2.1.

(2) Section 4.5 reads: '"Torque Deflection
Test. The headlamp assembly to be tested shall be
mounted in the designed vehicle position and set
at nominal aim (0.0). A special adapter (Figure
22) for the deflectometer (Figure 3) shall be
clamped onto the headlamp assembly. A torque of
20 in.-lbs. (2.25 N-m) shall be applied to the
headlamp assembly through the deflectometer,
and a reading on the thumb wheel shall be taken.
The torque shall be removed and a second read-
ing on the thumb wheel shall be taken."

(d) After a vibration test conducted in accord-
ance with paragraph S8.8, there shall be no evi-
dence of loose or broken parts, other than fila-
ments, visible without magnification. /^

(e) The maximum wattage at 12.8 volts (design
voltage) for the IGl and 2G1 upper beam is 55
watts and 43 watts respectively; for the 2GI
lower beam, 65 watts.

(f) A lens for a Type G headlamp incorporating
only part of an upper beam shall be labeled IGl.
A lens for a Type G headlamp incorporating both
parts of an upper beam and a lower beam shall
be labeled 2G1. The face of letters, numbers, or
other symbols molded on the surface of the lens
shall not be raised more than 0.020 in. (0.5 mm.),
and shall be placed no closer to the geometric
center of the lens than 1.375 in. (35 mm.). The
marking shall be molded in the lens and shall be
not less than '/i in. (6.35 mm) in size.

S7.3.9 Type H headlighting system. A Type H
headlamp system consisting of two Type 2H1
headlamps and associated hardware, which are
designed to conform to the following require-
ments:

(a) Paragraph S7.3.8(a) through (d).

(b) The maximum wattage at 12.8 volts (design /*■
voltage): 70 watts on the upper beam and 60 I
watts on the lower beam.

(Rev. 2/8/90)

PART 571; S

(c) A lens for a Type H headlamp incorporat-
ing both an upper beam and a lower beam shall
be labeled 2H1. The face of letters, numbers, or
other symbols molded on the surface of the lens
shall not be raised more than 0.020 in. (0.5 mm),
and shall be placed no closer to the geometric
center of the lens than 1.375 in. (35 mm.) The
marking shall be molded in the lens and shall be
not less than '/i in. (6.35 mm) in size.

S7.4 Integral Beam Headlighting System. An

integral beam headlighting system shall be
designed to conform to the following require-
ments:

(a) The system shall provide in total not more
than two upper beams and two lower beams of
the performance described in one of the follow-
ing:

(1) In a four-headlamp system, each upper
beam headlamp and each lower beam headlamp
shall be designed to conform to the photometries
of one of the following:

(i) Figure 15;

(ii) Figure 15 except that the upper beam test
values at 21/2 D-V and 2'/2 D-12R and 12L
shall apply to the lower headlamp and not to
the upper beam headlamp, and the upper beam
test point value at I'/i D-9R and 9L shall be
1,000, or

(iii) Table 2 of SAE J579 DEC 84.

(2) In a two-headlamp system, each
headlamp shall be designed to conform to the
photometries of one of the following:

(i) Figure 17; or

(ii) Table 1 of SAE J579 DEC 84.

(3) In a system in which there is more than
one beam contributor providing a lower beam,
and/or more than one beam contributor providing
an upper beam, each beam contributor in the sys-
tem shall be designed to meet only the photo-
metric performance requirements of Figure 15
based upon the following mathematical expres-
sion: conforming test point value = 2 (Figure 15
test point value)/total number of lower or upper
beam contributors for the vehicle, as appropriate.
The system shall be designed to use the Vehicle
Headlamp Aiming Device (VHAD) as specified
in paragraph S7.8.5.2.

(b) The lower and upper beams shall be pro-
vided only as follows where each headlamp con-
tains two light sources:

(1) The lower beam shall be provided either
by the most outboard light source (or the upper-
most if arranged vertically), or by all light
sources.

(2) The upper beam shall be provided either
by the most inboard light source (or the upper-
most if arranged vertically), or by all light
sources.

(1) The lower beam shall be provided by the
most outboard headlamps (or the uppermost if
arranged vertically), and the lens of each such
headlamp shall be permanently marked with the
letter "L."

(2) The upper shall be provided by the most
inboard headlamps (or lowermost if arranged ver-
tically), and the lens of each such headlamp shall
be permanently marked with the letter "U."

(d) A tolerance of ± Va degree realm tolerance
during photometric performance tests is permitted
for any headlamp. The test points 10U-90U shall
be measured from the normally exposed surface
of the lens face.

(e) A headlamp or beam contributor designed
to meet paragraphs (a)(1) or (a)(3) of this section
and S7.8.5.1 may be mounted in an assembly to
permit simultaneous aiming of the beam(s)
contributors, provided that with any complying
contributor the assembly complete with all lamps
meets the appropriate photometric requirements
when tested in accordance with SIO.

(f) Each integral beam headlamp system shall
be designed to conform to the applicable photo-
metric performance requirements in paragraph (a)
of this section when tested in accordance with
Sections 4.1 and 4.1.4 of SAE Standard J 1383
APR 85 with any headlamp intended for use in
such system. The term "aiming plane" means
"aiming reference plane," or an appropriate verti-
cal plane defined by the manufacturer as required
in paragraph S7.8.1.

(g) The system shall be aimable in accordance
with the requirements of paragraph S7.8. A sys-
tem that incorporates any headlamp or beam
contributor that does not have a VHAD as an
integral and indivisible part of the headlamp or
beam contributor shall be designed so that the
appropriate photometries are met when any cor-
rectly aimed and photometrically conforming
headlamp or beam contributor is removed from its

PART 571; S 108-15

mounting and aiming mechanism, and is replaced
without reaim by any conforming headlamp or
beam contributor of the same type.

(h) A headlamp with a glass lens need not meet
the abrasion resistance test (S8.2), or the chemical
resistance test (S8.3), or impact (S8.8) tests. If. in
addition to a glass lens, the headlamp uses a
nonplastic reflector, it need not meet the internal
heat test of paragraph S8.6.2. A headlamp of
sealed design as verified in paragraph S8.9 Seal-
ing need not meet the con-osion (S8.4), dust
(S8.5), or humidity (S8.7) tests, however, the
headlamp shall meet the requirements of para-
graphs 4.1, 4.1.2, 4.4 and 5.1.4 for corrosion and
connector of SAE Standard J580 DEC 86 Sealed
Beam Headlamp Assembly.

(i) When tested according to any of the proce-
dures indicated in subparagraphs (1) through (7)
each headlamp or beam contributor shall meet the
appropriate requirement:

(1) After an abrasion test conducted in
accordance with paragraph S8.2, the headlamp
shall meet the photometric requirements
applicable to the headlamp system under test.

(2) After a chemical resistance test involving
exposure to any of the fluids listed in paragraph
S8.3, there shall be no surface deterioration, coat-
ing delamination, fractures, deterioration of bond-
ing materials, color bleeding or color pickup visi-
ble without magnification, and the headlamp shall
meet the photometric requirements applicable to
the headlamp system under test.

(3) After a coiTosion test conducted in
accordance with paragraph S8.4 there shall be no
evidence of external or internal corrosion or rust
visible without magnification. Loss of adhesion of
any applied coating shall not occur more than
0.125 in. (3.2 mm) from any shaip edge on the
inside or outside. Corrosion may occur on termi-
nals only if the current produced during the test
of paragraph S8.4(c) is not less than 9.7 amperes.

(4) After a dust test conducted in accordance
with paragraph S8.5, the headlamp shall meet the
photometric requirements applicable to the
headlamp system under test.

(5) The headlamp shall first meet the
requirements of subparagraph (i) and then those
of subparagraph (ii).

(i) After a temperature cycle test conducted
in accordance with paragraph S8.6. 1, the
headlamp shall show no evidence of
delamination, fractures, entry of moisture or

deterioration of bonding material, color bleed-
ing, warpage or deformation visible without
magnification or lens warpage greater than .118 f^"
in. (3 mm) when measured parallel to the opti- *
cal axis at the point of intersection of the axis
of each light source with the exterior surface of
the lens, and it shall meet the photometric
requirements applicable to the headlamp system
under test.

(ii) After an internal heat test conducted in
accordance with paragraph S8.6.2, there shall
be no lens warpage greater than .118 in. (3
mm) when measured parallel to the optical axis
at the point of intersection of the axis of each
light source with the exterior surface of the
lens, and it shall meet the photometric require-
ments applicable to the headlamp system under
test.

(6) After a humidity test conducted in
accordance with paragraph S8.7, the inside of the
headlamp shall show no evidence of delamination
or moisture, fogging or condensation visible with-
out magnification.

(7) After a vibration test conducted in
accordance with paragraph S8.8, there shall be no
evidence of loose or broken parts, other than fila- ^
ments, visible without magnification. V^

S7.5 Replaceable Bulb Headlamp System.

Each replaceable bulb headlamp system shall
be designed to conform to the following require-
ments:

(a) The system shall provide only two lower
beams and two upper beams and shall incorporate
not more than two standardized replaceable light
sources in each headlamp.

(b) The photometries as specified in paragraphs
(c) through (e) of this section (depicted in Figure
26), using any standardized light source of the
Type intended for use in such system.

(c) The test requirements of sections 4.1, 4.1.4,
and performance requirements of section 5.1.4 of
SAE J 1383 April 85, using die photometric
requirements specified in paragraphs (d) and (e)
of this section. The term "aiming plane" means
"aiming reference plane," or an appropriate verti-
cal plane defined by the manufacturer as required
in paragraph [S7.8.1.] A Va degree reaim toler-
ance is permitted for any test point. The test .
points 10U-90U shall be measured from the nor- I
mally exposed surface of the lens face.

PART 571; S 108-16

(d) For a headlamp system equipped with dual
filament light sources. Type HBl light sources.
Type HB2 light sources. Type HB5 light sources,
or Types HBl and HB5 in combination, the fol-
lowing requirements apply:

(1) Headlamps designed to conform to the
external aiming requirements of [S7.8.5.1] shall
have no mechanism that allows adjustment of an
individual light source, or, if there are two light
sources, independent adjustment of each reflector.

(2) The lower and upper beams of a
headlamp system consisting of two lamps, each
containing one or two light sources, shall be pro-
vided as follows:

(i) The lower beam shall be provided in one
of the following ways:

(A) By the outboard light source (or upper
one if arranged vertically) designed to conform
to:

( 1 ) the lower beam requirements of Fig-
ure 17, if the light sources are type HB2; or

(B) Both light sources, in the headlamp
designed to confoirn to the lower beam require-
ments specified above for their Type.

(ii) The upper beam shall be provided in one
of the following ways:

(A) By the inboard light source (or the
lower one if arranged vertically) designed to
conform to:

(1) the upper beam requirements of
Table 1 of SAE Standard J579 DEC 84, if the
light sources are only Type HBl; or Type HB5,
or a combination thereof; or

(2) the upper beam requirements of Fig-
ure 17, if the light sources are Type HB2; or

(B) By both light sources in the headlamp,
designed to conform to the upper beam
photometries specified above for their type.

(3) The lower and upper beams of a
headlamp system consisting of four lamps, each
containing a single light source, shall be provided
as follows:

(i) The lower beam shall be provided by the
outboard lamp (or upper one if arranged verti-
cally), designed to conform to:

(A) the lower beam requirements of Table
1 of SAE Standard J579 DEC 84, if the light
sources are only Type HBl; or Type HB5, or
a combination thereof; or

(B) the lower beam requirements of Figure
15, if the light sources are Type HB2. The lens

of each such headlamp shall be marked with
the letter "L."

(ii) The upper beam shall be provided by the
inboard lamp (or the lower one if arranged ver-
tically), designed to conform to:

(A) the upper beam requirements of Table
1 of SAE Standard J579 DEC 84, if the light
sources are only Type HBl; or Type HB5, or
a combination thereof; or

(B) the upper beam requirements of Figure
15, if the light sources are Type HB2. The lens
of each such headlamp shall be marked with
the letter "'U."

(e) The following requirements apply to a
headlamp system equipped with any combination
of light sources except those specified in para-
graph (d) of this section:

[(1) Headlamps designed to conform to the
external requirements of S7.8.5.1 shall have no
mechanism that allows adjustment of an individ-
ual light source, or, if there are two light sources,
independent adjustment of each reflector. (57 F.R,
32738— July 23, 1992. Effective: August 24, 1992)]

(2) The lower and upper beams of a
headlamp system consisting of two lamps, each
containing two light sources (other than those
specified in paragraph (d) of this section) shall be
provided only as follows:

(i) The lower beam shall be provided in one
of the following ways:

(A) By the outboard light source (or the
uppermost if arranged vertically) designed to
conform to the lower beam requirements of
Figure 17; or

(B) By both light sources, designed to
conform to the lower beam requirements of
Figure 17.

(ii) The upper beam shall be provided in one
of the following ways:

(A) By the inboard light source (or the
lower one if arranged vertically) designed to
conform to the upper beam requirements of
Figure 17; or

(B) By both light sources, designed to
conform to the upper beam requirements of
Figure 17.

(3) The lower and upper beams of a
headlamp system consisting of four lamps, using
any combination of light sources except those
specified in paragraph (d) of this section, each
lamp containing only a single light source, shall
be provided only as follows:

PART 571; S 108-17

(Rev. 7/23/92)

(i) The lower beam shall be produced by the
outboard lamp (or upper one if arranged verti-
cally), designed to conform to the lower beam
requirements of Figure 15. The lens of each
such headlamp shall be permanently marked
with the letter "L."

(ii) The upper beam shall be produced by the
inboard lamp (or lower one if arranged verti-
cally), designed to conform to the upper beam
requirements of Figure 15. The lens of each
such headlamp shall be marked with the letter

(f) Each lens reflector unit manufactured as
replacement equipment shall be designed to con-
form to the requirements of paragraphs (d) and
(e) of this section when any standardized replace-
able light source appropriate for such unit is
inserted in it.

(g) The lens of each replaceable bulb headlamp
using any Type light source, except HBl used
singly or dually, within a headlamp system on a
motor vehicle, shall permanently display the Type
designation for that light source on the lens in
front of each light source.

(h) The system shall be aimable in accordance
with paragraph [S7.8.]

(i) Each headlamp shall meet the requirements
of paragraphs S7.4(h) and (i), except that the sen-
tence in (h) to verify sealing according to S8.9
Sealing does not apply.

[S7.6 Combination IHeadlighting System. A

combination headlighting system shall be com-
prised of either two headlamps designed to con-
form to the requirements of S7.6.2, or any com-
bination of four headlamps designed to conform to
the requirements of S7.3.7, S7.4, or S7.5 of this
standard.

[S7.6.1 A combination headlighting system shall
provide in total not more than two upper beams
and two lower beams. When installed on a motor
vehicle, the headlamps (or parts thereof) that pro-
vide the lower beam shall be of the same type,
and provide a symmetrical effective projected
luminous lens area when illuminated.

[S7.6.2 In a combination headlighting system
consisting of two headlamps, each headlamp shall
be designed to conform to Figure 17, and shall be
a combination of two different headlamps chosen
from the following types: a Type F headlamp, an

integral beam headlamp, and a replaceable bulb
headlamp.

[S7.6.2.1 That part of the headlamp which con- (
tains an integral beam headlamp, or beam
contributors used in place of a single headlamp,
shall be designed to conform to the requirements
of S7.4(c) through (i) of this standard.

[S7.6.2.2 That part of the headlamp which con-
tains a replaceable bulb headlamp shall be
designed to conform to the requirements of S7.5
of this standard.

[S7.6.3 In a combination headlighting system
consisting of four headlamps, each headlamp shall
be designed to conform to Figure 15, or if an
integral beam headlamp in which there is more
than one beam contributor, designed to conform to
Figure 15 in the manner required by S7.4(a)(3) of
this standard. (57 F.R, 32738— July 23, 1992. Effec-
tive: August 24, 1992)]

[S7.7] Standardized Replaceable Light
Sources. Each standardized replaceable light
source shall be designed to conform to the follow-
ing requirements:

(a) A Type HBl light source shall be designed |
to conform to the dimensions specified in Figure ^
3 and shall incorporate a silicone 0-ring. Its
maximum power on the lower beam shall be 50
watts, and on the upper beam, 70 watts. Its lumi-
nous flux in lumens shall be 700 ± 15% on the
lower beam and 1200 ± 15% on the upper beam.

(b) A Type HB2 light source shall be designed
to conform to the dimensions specified in Figure
23. Its maximum power on the lower beam shall
be 65 watts, and on the upper beam, 72 watts. Its
luminous flux in lumens shall be 910 plus or
minus 10% on the lower beam, and 1500 plus or
minus 10% on the upper beam.

19. Its maximum power on the upper beam shall
be 70 watts. Its luminous flux in lumens shall be
1700 ± 12%.

(d) A Type HB4 light source shall be designed
to conform to the dimensions specified in Figure

20. Its maximum power shall be 60 watts on the
lower beam, and its luminous flux in lumens on

the lower beam shall be 1000 ± 15%. |

(e) A Type HB5 light source shall be designed f
to conform to the dimensions specified in Figure

(Rev. 7/23/92)

PART 571; S 108-1 i

24. Its maximum power shall be 60 watts on the
lower beam, and 70 watts on the upper beam. Its
luminous flux in lumens shall be 1000 ± 15% on
the lower beam, and 1350 ± 15% on the upper
beam.

(f) The filament of a light source shall be sea-
soned before measurement of maximum power
and luminous flux.

(g) Measurement of maximum power and lumi-
nous flux shall be made with the direct current
test voltage regulated within one quarter of one
percent. The test voltage shall be design voltage,
12.8v. The measurement of luminous flux shall be
in accordance with the Illuminating Engineering
Society of North America, LM^5; lES Approved
Method for Electrical and Photometric Measure-
ments of General Service Incandescent Filament
Lamps (April 1980), shall be made with the black
cap installed on Types HBl. HB2, and HB4, and
Type HB5, and shall be made with the electrical
conductor and light source base shrouded with an
opaque white colored cover, except for the por-
tion normally located within the interior of the
lamp housing. The measurement of luminous flux
for the Types HB3 and HB4 shall be with the
base covered with a white cover shown in Figures
19-1 and 20-1. The white covers are used to
eliminate the likelihood of incorrect lumen
measurement that will occur should the reflec-
tance of the light source base and electrical
connector be low.

(h) The capsule, lead wires and/or terminals,
and seal on each Type HBl, Type HB3, Type
HB4, and Type HB5 light source shall be
installed in the base as shown in Figure 25 so as
to provide an airtight seal. Such a seal exists
when no air bubbles shall appear on the low pres-
sure (connector) side after the light source has
been immersed in water for one minute while
inserted in a cylindrical aperture specified for the
light source in Figure 25, and subjected to an air
pressure of 70 kPa (10 P.S.I.G.) on the glass cap-
sule side.

(i) After the force deflection test conducted in
accordance with 59, the permanent deflection of
the glass envelope shall not exceed 0.005 in.
(0.13mm) in the direction of the applied force.

(j) A general tolerance shall apply to Figure 3
as follows: ± 0.004 in. (0.10 mm) to all linear
dimensions and ± 1 degree 00 minutes to all
angular dimensions except for refefenced dimen-
sions and unless otherwise specified.

(k) Each standardized light source manufac-
tured on or after December 1, 1989, shall be
marked with the symbol DOT and with a name
or trademark in accordance with S7.2. In addition,
the base of each such light source shall be marked
with its HB Type designation.

[S7.8] Aimability Performance Requirements.

[S7.8.1] Each headlamp (other than a headlamp
designed to conform to paragraph S7.3), or beam
contributor, shall be equipped with fiducial marks,
aiming pads or similar references of sufficient
detail and accuracy for determination of an appro-
priate vehicle plane to be used with the photo-
metric procedures of SAE J 1383 APR 85 for cor-
rect alignment with the photometer axis when
being tested for photometric compliance, and to
serve for the aiming reference when the lamp is
installed on a motor vehicle. The fiducial marks,
aiming pads, or similar references are protrusions,
bubble vials, holes, indentations, ridges, scribed
lines, or other readily identifiable marks estab-
lished and described by the vehicle or lamp manu-
facturer.

[S7.8.2] Each headlamp shall be installed on a
motor vehicle with a mounting and aiming mecha-
nism that allows aim inspection and adjustment of
both vertical and horizontal aim, and is accessible
for those uses without removal of any vehicle
parts, except for protective covers removable with-
out the use of tools.

[S7.8.2.1] (a) When installed on the vehicle,
adjustment of one aim axis through its full on-
vehicle range shall not cause the aim of the other
axis to deviate more than ± 0.76 degree.

(b) If the performance specified in paragraph
(a) of this section is not achievable, the require-
ments of paragraph [S7. 8. 5. 2(b)(3)] apply, except
that if the aiming mechanism is not a VHAD, the
requirements specific to VHADs are not
applicable, and the instructions shall be specific to
the aiming mechanism installed.

[S7.8.2.2] If a headlamp is aimed by moving the
reflector relative to the lens and headlamp hous-
ing, or vice versa, it shall conform with the
photometries applicable to it with the lens at any
position relative to the reflector within the aim
range limits of paragraphs [S7.8.3] and [S7.8.4,]
or any combination.

PART 571: S 108-19

(Rev. 7/23/92)

[S7.8.3] When a headlamp system is tested in a
laboratory, the range of its vertical aim shall not
be less than ± 4 degrees from the nominal correct
air position for the intended vehicle appHcation.
When installed on a motor vehicle, the range of
vertical aim shall be not less than the full range
of pitch of the vehicle on which the headlamp sys-
tem is installed. The installed range of static pitch
angle shall as a minimum be determined from
unloaded vehicle weight to gross vehicle weight
rating, and incorporate pitch angle effects from
maximum trailer or truck loadings, the full range
of tire intemiix sizes and suspensions rec-
ommended and/or installed by the vehicle manu-
facturer, and the anticipated effects of variable
passenger loading. The vertical aim adjustment
mechanism shall be continuously adjustable over
the full range.

[S7.8.4] When a headlamp system is tested in a
laboratory, the range of its horizontal aim shall be
not less than 2.5 degrees from the nominal correct
aim position for the intended vehicle application.

[S7.8.5] When a headlamp system is installed on
a motor vehicle, it shall be aimable with either an
externally applied aiming device or on-vehicle
headlamp aiming devices installed by the vehicle
manufacturer. When activated in a steady-burning
state, headlamps shall not have any styling orna-
ment or other feature, such as a translucent cover
or grill, in front of the lens. Headlamp wipers may
be used in front of the lens provided that the
headlamp system is designed to confomi with all
applicable photometric requirements with the
wiper stopper in any position in front of the lens.

[S7.8.5.1] External aiming, (a) The aim of the

headlamps in each headlamp system, other than a
headlamp system designed to conform to section
S7.3, that is designed to use such external aiming
devices, shall not deviate more than 0.30 degree
when a downward torque of 20 in. -lb. (2.25 N-m)
is removed from the headlamp in its design
operating position. The downward force used to
create the torque shall be applied parallel to the
aiming reference plane, through the aiming pads,
and displaced forward using a lever arm such that
the force is applied on an axis that is prpendicular
to the aiming reference plane and originates at the

center of the aiming pad pattern (see Figures 4-
1 and 4-3). For headlamps using the aiming pad
locations of Group 1, the distance between the ^
point of application of force and the aiming ref- '
erence plane shall be not less than 6.625 in. (168.3
mm) plus the distance from the aiming reference
plane to the secondary plane, if used {see section
[S7.8.5. 1(d)(1)).] For headlamps using the aiming
pad locations of Group II, the distance between
the point of application of force and the aiming
reference plane shall be not less than 6.609 in.
(167.9 mm) plus the distance from the aiming ref-
erence plane to the secondary plane, if used. For
headlamps using the nonadjustable Headlamp
Aiming Device Locating Plates for the 146 mm
diameter, the 176 mm diameter, and the 92 x 150
mm sealed beam units, the distance between the
point of application of force and the aiming plane
shall, respectively, be not less than 6.984 in.
(177.4 mm), 6.937 in. (176.2 mm), and 7.625 in.
(193.7 mm).

Each headlamp system that is designed to con-
form to paragraph S7.5 and that is designed to
use such external aiming devices, and which is
manufactured on or after December 1, 1989, shall
comply with this paragraph. ^^

(b) When a headlamp is installed on a motor ^^
vehicle, its aim in any direction shall not change

by more than 0.30 degree nor shall the lamp
recede more than 0.1 in. (2.5 mm) after being
subjected to an inward force of 50 pounds (222
newtons) applied evenly to the lens parallel to the
mechanical axis.

(c) Each headlamp system mounting and aim-
ing mechanism shall be subjected to a salt spray
(fog) test in accordance with ASTM B 1 17-73
Method of Salt Spray (Fog) Testing for a period
of 50 hours, consisting of two successive 25 hour
periods of 24 hours exposure followed by 1 hour
of drying. At the end of 50 hours, the headlamp
system shall be capable of meeting any of the
applicable requirements of paragraph [S7.8.]

(d) Each headlamp system which is designed to
use the Headlamp Aiming Device Locating Plates
with adjustable legs for the 100 x 165 mm unit
and the 142 x 200 mm unit, and which has
adjustable length legs, shall meet the requirements
of subparagraphs (1) and (2) below.

(Rev. 7/23/92)

PART 571; S 108-20

Figure 2. — Minimum Luminous Intensity Plate for the 100 x 165 mm unit, the 142 x 200
Requirement for Backup Lamps mm unit, the 146 mm diameter unit, or the 178
mm diameter unit of SAE J602, or the 92 x 150

Group Test point, degrees °'de\a{se7note 7" tnm Type F unit, and incorporate lens mounted
aiming pads as specified for those units in Figures

1' 45L-5U, 45L-H, 45L-5D 45 , r, i ? c n .■^■ c a c moi! add

: 10, 13, 5, or 7 respectively m SAE J 1383 APR

2' 30L-H, 30L-5D 50 85, or Figure 11 of this standard for the Type F

~^ '^^^ 10L-5U. V- 100 ""'^- ^^ ^° designed, no additional lens marking is

' lou, V-5U, lOR-iou. necessary to designate the type of plate or dimen-

10R-5U. sions.

' 'VloR-n'm-fD.''^ "'" [S7.8.5.2] On-vehicle aiming. Each headlamp

'- system that is capable of being aimed by equip-

5 ' 30R-H, 30R-5D 50 ^gj^t installed on the vehicle shall include a

6 ' 45R-5U 45R-H, 45R-5D 45 Vehicle Headlamp Aiming Device ( VHAD) that

conforms to the following requirements:

' When 2 lamps of the same or symmetrically opposite design are , -. . ■ -r-i ^rtxAT^ u n j r u ji

used, the reading along the vertical axis and the averages of the (a) Aim. The VHAD Shall provide tor headlamp

readings for the same angles left and right of vertical for 1 lamp ^jj. inspection and adjustment in both the vertical

shall be used to determine compliance with the requirements. If 2 ^ J

lamps of differing designs are used, they shall be tested individually and horizontal aXCS.

twfceleTl^ddaleluir^Ltr'" '''' ""^ '=°"'""'' ""'" ■""' (D Vertical aim: The VHAD shall include

When only I backup lamp is used on the vehicle, it shall he []^q necessary references and scales relative to the

tested to twice the candela requirements. , . , , • i ■ r

horizontal plane to assure correct vertical aim ror

(1) The lens shall have three aiming pads photometry and aiming purposes. An off- vehicle
which meet the requirements of Figure 4, Dimen- measurement of the angle of the plane of the
sional Specifications for Location of Aiming Pads ground is permitted. In addition, an equal number
on Replaceable Bulb Headlamp Units. The aiming of graduations from the "O" position represent-
pads need not be centered at the geometric center ing angular changes in the axis in the upward and
of the lens, or on the optical axis. Except as pro- downward directions shall be provided.

vided in subparagraph (2), a whole number, (i) Each graduation shall represent a change

which represents the distance in tenths of an inch in the vertical position of the mechanical axis

(i.e., 0.3 inch=3) from the aiming reference plane not larger then 0.19 degree (1 in. at 25 ft.) to

to the respective aiming pads which are not in provide for variations in aim at least 1.2

contact with that plane, shall be inscribed adjacent degrees above and below the horizontal, and

to each respective aiming pad on the lens. The have an accuracy relative to the zero mark of

height of these numbers shall be not less than less than 0.1 degree.

.157 in. (4 mm). If there is interference between (ii) The VHAD shall be marked to indicate

the plane and the area of the lens between the headlamp aim movement in the upward and

aiming pads, the whole number represents the dis- downward directions.

tance to a secondary plane. The secondary plane (iii) Each graduation shall indicate a linear
shall be located parallel to the aiming reference movement of the scale indicator of not less
plane and as close to the lens as possible without than 0.05 in. (1.27 mm) if a direct reading ana-
causing interference. log indicator is used. If a remote reading

(2) If the most forward aiming pad is the indicator is provided, it shall represent the
lower inboard aiming pad, then the dimensions actual aim movement in a clear, understandable
may be placed anywhere on the lens. The dimen- format.

sion for the outboard aiming pad (Dimension F in (iv) The vertical indicator shall perform

Figure 4) shall be followed by the letter "H"" and through a minimum range of ± 1.2 degrees,

the dimension for the center aiming pad shall be (v) Means shall be provided in the VHAD

followed by the letter "V." The dimensions shall for compensation for deviations in floor slope

be expressed in tenths of an inch. not less than 1.2 degrees from the horizontal

(e) Each headlamp may be designed to use the that would affect the correct positioning of the

nonadjustable Headlamp Aiming Device Locating headlamp for vertical aim.

PART 57 1; S 108-2 1 (Rev. 7/23«2)

(vi) The graduations shall be legible under
an illumination level not greater than 30 foot
candles, measured at the top of the graduation,
by an observer having 20/20 vision (Snellen),
and shall permit aim adjustment to within 0.19
degree (1 in. at 25 ft.).

(2) Horizontal aim. The VHAD shall include
references and scales relative to the longitudinal
axis of the vehicle necessary to assure correct
horizontal aim for photometry and aiming pur-
poses. An "O" mark shall be used to indicate
alignment of the headlamps relative to the
longitudinal axis of the vehicle. In addition, an
equal number of graduations from the "O" posi-
tion representing equal angular changes in the
axis relative to the vehicle axis shall be provided,
(i) Each graduation shall represent a change
in the horizontal position of the mechanical
axis not greater than 0.35 degree (2 in. at 25
ft.) to provide for variations in aim at least 0.76
degree (4 in. at 25 ft.) to the left and right of
the longitudinal axis of the vehicle, and shall
have an accuracy relative to the zero mark of
less than 0. 1 degree.

(ii) The VHAD shall be marked to indicate
headlamp aim movement in the left and right
directions.

(iii) The graduations shall be legible under
an illumination level not greater than 30 foot
candles, measured at the top of the top of the
radiator, by an observer having 20/20 vision
(Snellen), and shall permit aim adjustment to
within 0.38 degree (2 in. at 25 ft.).

(iv) The horizontal indicator shall perform
through a minimum range of ± 0.76 degree (4
in. at 25 ft.); however, the indicator itself shall
be capable of recalibration over a movement of
± 2.5 degrees relative to the longitudinal axis
of the vehicle to accommodate any adjustment
necessary for recalibrating the indicator after
vehicle repair from accident damage,
(b) Aiming instructions. (1) The instructions for
properly aiming the headlighting system using the
VHAD shall be provided on a label permanently
affixed to the vehicle adjacent to the VHAD, or
in the vehicle operator's manual. The instructions
shall advise that the headlighting system is prop-
erly aimed if the appropriate vertical plane (as
defined by the vehicle manufacturer) is per-
pendicular to both the longitudinal axis of the
vehicle, and a horizontal plane when the vehicle

is on a horizontal surface, and the VHAD is set
at "O" vertical and "O" horizontal. ^

(2) Should a remote indicator or a remote I
indicator and adjuster be provided, the instruc-
tions shall be placed in the operator's manual, and
may also be placed on a label adjacent to the
VHAD.

(3) Should the mechanism not meet the require-
ments of [S7.8.2.1,] on each motor vehicle
manufactured on or after September 1, 1990, a
cautionary label shall be placed adjacent to the
mechanism stating the caution and including
either the reason for the caution or the corrective
action necessary. Each such label shall also refer
the reader to the vehicle operator's manual for
complete instructions. Each such vehicle shall be
equipped with an operator's manual containing
the complete instructions appropriate for the
mechanism installed.

(1) The headlamp assembly (the headlamp(s)
and the VHAD(s) mechanism) shall be mounted
on a level goniometer, aligned to a photometer
located not less than 60 ft. (18.3m) from the
VHAD assembly. The assembly shall be mechani-
cally aimed using the VHAD in accordance with /^
the manufacturer's instructions as provided with

the vehicle on which the VHAD is intended to be
used. A '/4 degree realm is permitted in any direc-
tion at any test point to allow for variations in
readings between laboratories. The test shall be
conducted in accordance with the procedures of
paragraphs 4.1 and 4.1.4 of SAE J 1383 APR 85.
Under these conditions the mounted headlamp
assembly shall be designed to conform to the
photometric requirements appropriate for the
headlamp system under test.

(2) When tested in accordance with sub-
section (1) of this section, with any replacement
headlamp unit(s) or light sources intended for use
in the system under test, the VHAD and
headlamp system shall be designed to conform to
the photometric performance requirements appro-
priate for the system under test.

(3) The same VHAD and associated
headlamp(s) (or headlamp assembly) shall be rig-
idly mounted in a headlamp test fixture and com-
ply with the following laboratory test procedures:

(i) Each graduation on the horizontal and .
vertical aim scales shall be checked and any »
variation from the correct aim shall not exceed
± 0.2 degree, and ± 0.1 degree, respectively.

(Rev. 7/23/92)

PART 571; S 108-22

(ii) With the aiming plane horizontal and
vertical and with the scale on the device set at
O, the aimer shall be adjusted before each of
the following tests to assure that the indicators
are centered at O.

(ii)(A) The VHAD and an unlighted
headlamp assembly shall be stabilized at 20 ±
degrees F (-7 ± 3 degrees C) in a circulating
air environmental test chamber. After a period
of 30 minutes, when measured at that soak
temperature, the variation from correct hori-
zontal or vertical aim shall not exceed ± 0.2
degree, and ± 0. 1 degree, respectively.

(ii)(B) The VHAD, and the headlamp assem-
bly with its highest wattage filament (or com-
bination of filaments intended to be used
simultaneously) energized at its design voltage,
shall than be stabilized at 100 ± 5 degrees F
(38 ± 3 degrees C) in a circulating air environ-
mental test chamber. After a period of 30 min-
utes, when measured at that soak temperature,
the variation from correct horizontal and verti-
cal aim shall not exceed ± 0.2 degree, and ±
0.1 degree, respectively.

(ii)(c) The VHAD and an unlighted
headlamp assembly shall then be placed in a
circulating air environmental test chamber and
exposed to a temperature of 140 ± 5 degrees F
(60 ± 3 degrees C) for 24 hours, followed by
a temperature of -40 + 5 degrees F ( - 40 ±
3 degrees C) for 24 hours and then permitted
to return to room temperature, after which the
VHAD and headlamp assembly shall show no
damage which would impair its ability to per-
form as specified herein. The variation from
correct horizontal or vertical aim shall not
exceed ± 0.2 degree, and ± 0.1 degree, respec-
tively.

(ii)(d) The VHAD and headlamp assembly
shall then be tested according to the corrosion
test procedure of paragraph [S7. 8. 5. 1(c).]

(ii)(E) The VHAD and headlamp assembly
shall then be tested for photometric compliance
as specified in paragraphs [S7.7.5.2(c)(l) and
(2).]

S8 Tests and Procedures for Integral Beam
and Replaceable Bulb Headlighting Systems.

When tested in accordance with the following
procedures, each integral beam headlamp shall
meet the requirements of paragraph S7.4, and each

replaceable bulb headlamp shall meet the require-
ments of paragraph S7.5.

58.1 Photometry. Each headlamp to which
paragraph S8 applies shall be tested according to
paragraphs 4.1 and 4.1.4 of SAE Standard J 1383
APR 85 for meeting the applicable photometric
requirements, after each test specified in para-
graphs S8.2, S8.3, S8.5, S8.6.1, S8.6.2, and S8.7.
A Va degree realm is permitted in any direction at
any testpoint.

58.2 Abrasion, (a) A headlamp shall be
mounted in the abrasion-test fixture in the manner
indicated in Figure 5 with the lens facing upward.

(b) An abrading pad meeting the requirements
in paragraphs (c)(1) through (c)(4) of this section
shall be cycled back and forth (1 cycle) for 11
cycles at 4±0.8 in. (10 cm ± 2 cm) per second
over at least 80 percent of the lens surface,
including all the area between the upper and
lower aiming pads, but not including lens covers
and edges.

(c)(1) The abrading pad shall be not less than
1.0 ± .04 in. (2.5 cm ± .1 cm) wide, constructed
of 0000 steel wool, and rubber cemented to a
rigid base shaped to the same vertical contour of
the lens. The "grain" of the pad shall be per-
pendicular to the direction of motion.

(2) The abrading pad support shall be equal
in size to the pad and the center of the support
surface shall be within ± .08 in. (± 2 mm) of par-
allel to the lens surface.

(3) The density of the abrading pad shall be
such that when the pad is mounted to its support
and is resting unweighted on the lens, the base of
the pad shall be no closer than .125 in. (3.2 mm)
to the lens at its closest point.

(4) When mounted on its support and resting
on the lens of the test headlamp, the abrading pad
shall then be weighted such that a pad pressure of
2.0 ± .15 psi (14 ± 1 kPa) exists at the center and
perpendicular to the face of the lens.

(d) A pivot shall be used if it is required to fol-
low the contour of the lens.

(e) Unused steel wool shall be used for each
test.

58.3 Chemical resistance, (a) The entire exte-
rior lens surface of the fixtured headlamp and top
surface of the lens-reflector joint shall be wiped
once to the left and once to the right with a 6-

PART571; S 108-23

(Rev. 7/23/92)

inch square soft cotton cloth (with pressure
equally applied) which has been saturated once in
a container with 2 ounces of one of the test fluids
listed in paragraph (b) of this section. The lamp
shall be wiped within 5 seconds after removal of
the cloth from the test fluid.

(b) The test fluids are:

(1) ASTM Reference Fuel C, which is com-
posed of Isooctane 50 volume % and Toluene 50
volume %. Isooctane must conform to A2.7 in
Annex 2 of the Motor Fuels Section of the 1985
Annual Book of ASTM Standards Vol. 05.04, and
Toluene must conform to ASTM specification
D362-84, Standard Specification for Industrial
Grade Toluene. ASTM Reference Fuel C must be
used as specified in:

(i) Paragraph A2.3.2 and A2.3.3 of Annex 2
to Motor Fuels, Section 1 in the 1985 Annual
Book of ASTM Standards; and

(ii) OSHA Standard 29 CFR 1910.106—
Handling Storage and Use of Flammable
Combustible Liquids.

(2) Tar remover (consisting by volume of
45% xylene and 55% petroleum base mineral
spirits).

(3) Power steering fluid (as specified by the
vehicle manufacturer for use in the motor vehicle
on which the headlamp is intended to be
installed).

(4) Windshield washer fluid consisting of
0.5% monoethanolamine with the remainder 50%
concentrations of methanol/distilled water by vol-
ume.

(5) Antifreeze (50% concentration of ethyl-
ene glycol/distilled water by volume).

(c) After the headlamp has been wiped with the
test fluid, it shall be stored in designed operating
attitude for 48 hours at a temperature of 73 ° F
± 7° (23°C ± 4°) and a relative humidity of 30
± 10 percent. At the end of the 48-hour period,
the headlamp shall be wiped clean with a soft dry
cotton cloth and visually inspected.

[S8.4] Corrosion, (a) A connector test shall be
performed on each filament circuit prior to the test
in subparagraph (b) according to Figure 1 of SAE
Standard J580, [DEC 86 J. The power source shall
be set to provide 12.8 volts and the resistance
shall be set to produce 10 amperes.

(b) The headlamp with connector attached to
the terminals, unfixtured and in its designed
operating attitude with all drain holes, breathing

devices or other designed openings in their nor-
mal operating positions, shall be subjected to a
salt spray (fog) test in accordance with ASTM t"
B 117-73, Method of Salt Spray (FOG) Testing.
for a period of 240 hours, consisting of 10
successive 24-hour periods. During each interval,
the headlamp shall be mounted in the middle of
the chamber and exposed for 23 hours to the salt
spray. The spray shall not be activated for the
24th hour. The bulb shall be removed from the
headlamp and from the test chamber during the
one hour of salt spray deactivation and reinserted
for the start of the next test cycle, at the end of
the first and last three 23-hour periods of salt
spray exposure, and at the end of any two of the
fourth through seventh 23-hour periods of salt-
spray exposure. The test chamber shall be closed
at all times except for a maximum of 2 minutes
which is allowed for removal or replacement of
a bulb during each period. After the ten cycles,
the lens reflector unit without the bulb shall be
immersed in deionized water for five minutes,
then secured and allowed to dry by natural
convection only.

(c) Using the voltage, resistance and pretest
setup of subparagraph (a), the current in each fila- ^
ment circuit shall be measured after the test con- ^
ducted in subparagraph (b).

[S8.5] Dust. The headlamp, mounted on a
headlamp test fixture, with all drain holes, breath-
ing devices or other designed openings in their
normal operating positions, shall be positioned
within a cubical box, with inside measurements of
35.4 in. (900 mm) on each side, or larger if
required for adequate wall clearance, i.e., a dis-
tance of at least 5.9 in. (150 mm) between the
headlamp and any wall of the box. The box shall
contain 9.9 lb. (4.5 kg) of fine powdered cement
which conforms to the ASTM CI 50-77 Specifica-
tion for Portland Cement. Every 15 minutes, the
cement shall be agitated by compressed air or fan
blower(s) by projecting blasts of air for a 2-second
period in a downward direction so that the cement
is diffused as uniformly as possible throughout the
entire box. This test shall be continued for five
hours, after which the exterior surfaces of the
headlamp shall be wiped clean.

S8.6 Temperature and Internal heat test. A £''

headlamp with one or more standardized replace- "
able light sources shall be tested according to

(Rev. 5/9/92)

PART 571; S 108-24

S8.6.1 and S8.6.2. Tests shall be made with all
filaments lighted at design voltage that are
intended to be used simultaneously in the
headlamp and which in combination draw the
highest total wattage. These include but are not
limited to filaments used for turn signal lamps, fog
lamps, parking lamps, and headlamp lower beams
lighted with upper beams when the wiring harness
is so connected on the vehicle. If a turn signal is
included in the headlamp assembly, it shall be
operated at 90 flashes a minute with a 75 ± 2%
current "on time". If the lamp produces both the
upper and lower beam, it shall be tested in both
the upper beam mode and the lower beam mode
under the conditions above described, except for a
headlamp with a single Type HBl or HB2 light

58.6.1 Temperature cycle. A headlamp
mounted on a headlamp test fixture, shall be sub-
jected to 10 complete consecutive cycles having
the thermal cycle profile shown in Figure 6. Dur-
ing the hot cycle, the lamp shall be energized
commencing at point "A" of Figure 6 and de-
energized at point "B." Separate or single test

k chambers may be used to generate the environ-
W ment of Figure 6. All drain holes, breathing
devices or other openings or vents of the
headlamp shall be in their normal operating posi-
tions.

58.6.2 internal Heat Test, (a) The headlamp
lens surface that would normally be exposed to
road dirt shall be unifonnly sprayed with any
appropriate mixture of dust and water or other
appropriate materials to reduce the photometric
output at the H-V test point of the upper beam (or
the '/2D-I '/2R test point of the lower beam as
appropriate) to 25 ± 2% of the output originally
measured in the photometric test conducted pursu-
ant to paragraphs S7.4(i), or S7.5(a) through (e),
as applicable. A headlamp with a single Type
HBl or HB2 light source shall be tested on the
upper beam only.

Such reduction shall be determined under the
same conditions as that of the original photo-
metric measurement.

(b) After the photometric output of the lamp
has been reduced as specified in paragraph (a),
I the lamp and its mounting hardware shall be

mounted in an environmental chamber in a man-
ner similar to that indicated in Figure 7, Din/

Ambient Test Setup. The headlamp shall be
soaked for one hour at a temperature of 95 -I- 7-
degrees F (35-1-4-0 degrees C) and then the
lamp shall be energized according to S8.6 for one
hour in a still air condition, allowing the tempera-
ture to rise from the soak temperature.

(c) The lamp shall be returned to a room
ambient temperature of 73 -I- 7-0 degrees F
(23 -f- 4 — degrees C) and a relative humidity of
30 ± 10% and allowed to stabilize to the room
ambient temperature. The lens shall then be
cleaned.

S8.7 Humidity, [(a) The test fixture consists of
a horizontal steel plate to which three threaded
steel or aluminum rods of V2 inch diameter are
screwed vertically behind the headlamp. The
headlamp assembly is clamped to the vertical
rods, which are behind the headlamp. All attach-
ments to the headlamp assembly are made behind
the lens and vents or openings, are not within 2
inches laterally of a vent inlet or outlet.

(b) The mounted headlamp assembly is ori-
ented in its design operating position, and is
placed in a controlled environment at a tempera-
ture of 1 00-1- 7-0 degrees F (38-1-4-0 degrees
C) with a relative humidity of not less than 90
percent. All drain holes, breathing devices, and
other openings are in their normal operation posi-
tions for all phases of the humidity test. The
headlamp shall be subjected to 24 consecutive 3-
hour test cycles. In each cycle, it shall be ener-
gized for 1 hour at design voltage with the high-
est combination of filament wattages that are
intended to be used, and then deenergized for 2
hours. If the headlamp incorporates a turn signal,
it shall flash at 90 flashes per minute with a 75
± 2 percent current "on-time."

(c) Within 3 minutes after the completion of
the 24th cycle, the air flow test will begin. The
following shall occur: the mounted assembly shall
be removed, placed in an insulating box and cov-
ered with foam material so that there is no visible
air space around the assembly; the box shall be
closed, taken to the air flow test chamber, and
placed within it. Inside the chamber, the assembly
with respect to the airflow, shall be oriented in its
design operating position. The assembly is posi-
tioned in the chamber so that the center of the
lens is in the center of the opening of the air flow
entry during the test. The headlamp has at least
3 inches clearance on all sides, and at least 4

PART 571; S 108-25

(Rev. 3/11/91)

inches to the entry and exit ducts at the closest
points. If vent tubes are used which extend below
the lamp body, the 3 inches are measured from
the bottom of the vent tube or its protection. The
temperature of the chamber is 73 + 4-0 degrees
F (23 + 4 — degrees C) with a relative humidity
of 30+10 — percent. The headlamp is not ener-
gized.

(d) Before the test specified in paragraph (e) of
this section, the uniformity of the air flow in the
empty test chamber at a plane 4 inches down-
stream of the air entry duct shall have been meas-
ured over a 4-inch square grid. The uniformity of
air flow at each grid point is + 10 percent of the
average air flow specified in paragraph (e) of this
section.

(e) The mounted assembly in the chamber shall
be exposed, for one hour, to an average flow of
330 + 0-30 ft/min. as measured with an air
velocity measuring probe having an accuracy of ±
3 percent in the 330 ft/min. range. The average
air flow is the average of the velocity recorded at
six points around the perimeter of the lens. The
six points are determined as follows: at the center
of the lens, construct a horizontal plane. The first
two points are located in the plane, 1 inch out-
ward from the intersection of the plane and each
edge of the lens. Then, trisect the distance
between these two points and construct longitu-
dinal vertical planes at the two intermediate loca-
tions formed by the trisection. The four remaining
points are located in the vertical planes, one inch
above the top edge of the lens, and one inch
below the bottom edge of the lens.

(f) After one hour, the headlamp is removed
and inspected for moisture. (56 F.R. 10185 —
March 11, 1991. Effective: September 9, 1991)]

S8.8 Vibration. A vibration test shall be con-
ducted in accordance with the procedures of SAE
Standard J575e Tests for Motor Vehicle Lighting
Devices and Components August 1970, and the
following: The table on the adapter plate shall be
of sufficient size to completely contain the test
fixture base with no overhang. The vibration shall
be applied in the vertical axis of the headlamp
system as mounted on the vehicle. The filament
shall not be energized.

[S8.9 Sealing. An unfixtured headlamp in its
design mounting position shall be placed in water
at a temperature of 176 ± 5 degrees F (60 ± 3

degrees C) for one hour. The headlamp shall be
energized in its highest wattage mode, with the
test voltage at 12.8 + 0.1 V. during immersion. •
The lamp shall then be de-energized and imme-
diately submerged in its design mounting position
into water at 32 +5-0 degrees F (0 +3-0
degrees C). The water shall be in a pressurized
vessel, and the pressure shall be increased to psi
(70 kPa), upon placing the lamp in the water. The
lamp shall remain in the pressurized vessel for a
period of thirty minutes. This entire procedure
shall be repeated for four cycles. Then the lamp
shall be inspected for any signs of water on its
interior. During the high temperature portion of
the cycles, the lamp shall be observed for signs of
air escaping from its interior. If any water occurs
on the interior or air escapes, the lamp is not a
sealed lamp.

S9 Deflection test for standardized replace-
able light sources. With the light source rigidly
mounted in a fixture in a manner indicated in Fig-
ure 8, a force of 4.0 ± 0.1 pounds (17.8 ± 0.4N)
is applied at a distance "A" from the reference
plane perpendicular to the longitudinal axis of the
glass capsule and parallel to the smallest dimen-
sion of the pressed glass capsule seal. The force •
shall be applied (using a rod with a hard rubber
tip with a minimum spherical radius of .039 in ( 1
mm) radially to the surface of the glass capsule in
four locations in a plane parallel to the reference
plane and spaced at a distance "A" from that
plane. These force applications shall be spaced 90
degrees apart starting at the point perpendicular to
the smallest dimension of the pressed seal of the
glass capsule. The bulb deflection shall be meas-
ured at the glass capsule surface at 180 degrees
opposite to the force application.

S10 Simultaneous Aim Photometry Tests.

(a) Type F Headlamp Systems. The assembly
shall be located on a goniometer placed not less
than 60 feet (18.3 m) from the photometer. The
LF unit shall be aimed mechanically by centering
the unit on the photometer axis and by aligning
the aiming plane of the lens perpendicular to the
photometer axis. Then the assembly shall be
moved in a plane parallel to the established aim-
ing plane of the LF headlamp until the UF
headlamp is centered on the photometer axis.
Photometry measurements of the UF photometry 1

unit shall be completed using the aiming plane so
established, and the procedures of section S4.1

(Rev. 3/11/91)

PART 571; S 108-26

and 4.1.4 Standard J1383 APR 85, and Figure 15.
A realm tolerance of ± '/t degree is permitted in
any direction at any test point.

(b) Integral Beam Headlamp Systems. The
assembly used for simultaneously aiming more
than one integral beam headlamp shall be placed
on a test fixture on a goniometer located not less
than 60 feet (18.3 m) from the photometer. The
assembly shall be aimed by centering the geo-
metric center of the lower beam lens(es) on the
photometer axis and by aligning the photometer
axis to be perpendicular to the aiming reference
plane or appropriate vertical plane defined by the
manufacturer of any lower beam contributor.
Photometric compliance of the lower beam shall

be determined with all lower beam contributors
illuminated and in accordance with sections 4.1
and 4.1.6 of SAE Standard J 1383 APR 85, and
Figure 15. The assembly shall then be moved in
a plane parallel to the established aiming plane of
the lower beam until the assembly is located with
the geometric center of the upper lens(es) on the
photometer axis. Photometric compliance for
upper beam shall now be determined using the
figure and procedure specified for the lower
beam. During photometric testing, a '/» degree
realm is permitted in any direction at any test
point.

35 F.R. 16842
October 31, 1970

PART 571; S 108-27

(Rev. 3/11/91)

Table I. — Required Motor Vehicle Lighting Equipment Other Than Headlamps — Multipurpose Passenger
Vehicles, Trucks, Trailers, and Buses, of 80 or More Inches Overall Width

Item

Multipurpose passenger vehicles,
trucks and buses

Trailers

Applicable SAE standards or
recommended practice

Column 1

Column 2

Column 3

Column 4

Taillamps^

2 red

J585e. September 1977

Stoplamps

2 red

SAE Jl 398 May 1985

License plate lamp '

1 while

1 white

J587, October 1981

Reflex reflectors

4 red; 2

amber

4 red; 2 amber

J594f, January 1977

Side marker lamps

4 red; 2

amber

2 red; 2 amber

J592e, July 1972

Backup lamp '

1 white

None

J593C, February 1968

Turn signal lamps

2 red or amber; 2 amber

2 red or amber

SAE J 1395 April 1985

Turn signal operating unit '

None

J589. April 1964

Turn signal flasher

None

J590b. October 1965

Vehicular hazard warning signal op-
erating unit

None

J910. January 1966

Vehicular hazard warning signal
flasher

None

J945. February 1966

Identification lamps

3 amber;

3 red

J592e, July 1972

Clearance lamps

2 amber;

2 red

2 amber; :

2 red

J592e. July 1972

Intermediate side marker lamps *

2 amber

J592e, July 1972

Intermediate side reflex reflectors ■*
[Conspicuity

2 amber
See S5.7

2 amber
See S.5.7

J594f. January 1977
See S5.7]

(57 F.R. 58406— December 10, 1992, Effective: December 1, 1993.)

'See S5. 1.1. 10. -See S5. 1.1.1 1-12. 'SeeS5.5.6. -"See S5.

PART 571: S 108-29

(Rev. 12/10/92)

-Location of Required Motor Veiiicle Lighting Equipment Multipurpose Passenger Vehicles,
Trucks. Trailers, and Buses, Of 80 Or More Inches Overall Width

Column 2

On the from, each headlamp provid- Not required
ing the upper beam, at the same
height, 1 on each side of the verti-
cal centerline, each headlamp pro-
viding the lower beam, at the same
height. 1 on each side of the verti-
cal centerline, as far apart as prac-
ticable. See also S7

Taillamps

On the rear, 1 on each side of the On the rear, 1 on each side of the Not less than !5 inches, nor more
vertical centerline, at the same vertical centerline, at the same than 72 inches,
height, and as far apart as prac- height, and as far apan as prac-

Stoplamps

On the rear, 1 on each side of the
vertical centerline, at the same
height, and as far apart as prac-

On the rear. 1

on each side of the

Not less than 15 inches.

nor more

vertical ceni

terline. at the same

than 72 inches.

height, and

as far apart as prac-

ticable

License-plate lamp

At rear license plate, to illuminate the At rear license plate to ill
plate from the top or sides plate from the top or sides

the No requirement.

On the rear

Not required

Turn-signal lamps

At or near the front — ! amber on
each side of the vertical centerline.
at the same height, and as far apart
as practicable.

On the rear — 1 red or amber on each
side of the vertical centerline. at
the same height, and as far apart as
practicable

On the rear — I red or amber on each
side of the vertical centerline, at
the same height, and as far apart as
practicable

inches, nor more

Identification lamps

On the front and rear — i lamps,
amber in front, red in rear, as close
as practicable to the top of the ve-
hicle, at the same height, as close
as practicable to the vertical cen-
terline with lamp centers spaced
not less than 6 inches or more than
12 inches apart. Alternatively, the
front lamps may be located as
close as practicable to the top of
the cab

On the rear — 3 lamps as close as
practicable to the top of the vehicle
at the same height, as close as
practicable to the vertical center-
line, with lamp centers spaced not
less than 6 inches or more than 12
inches apart.)

On the front only — No part of the
lamp or mountings shall extend
below the top of the vehicle's
windshield.

Clearance lamps

On the front and rear — 2 amber On the

lamps on front, 2 red lamps on
rear, to indicate the overall width
of the vehicle, one on each side of
the vertical centerline, at the same
height, and as near the top as prac-
ticable

and rear — 2 amber No requirement.

lamps on front, 2 red lamps on
rear, to indicate the overall width
of the vehicle, one on each side of
the vertical centerline, at the same
height, and as near the top thereof
as practicable

Intermediate side
marker lamps

On each side — 1 amber lamp located On each side — 1 amber lamp located Not less than 15 inches,
the midpoint between at or near the midpoint between

the front
lamps

and rear side-marker

the front and
lamps

side marker

Intermediate side re-
flex reflectors

IConspicuity

On each side — 1 amber located at oi
near the midpoint between the
front and rear side reflex reflectors

See S5.7 See S.5.7

On each side — 1 amber located at or
near the midpoint between the
front and rear side reflex reflectors

15 inches nor more

See S5.7]

Reflex reflectors

On the rear — 1 red on each side of On the rear — 1 red on each side of

the vertical centerline, as far apart
as practicable, and at the same
height.
On each side — 1 red as far to the rear
as practicable, and 1 amber as far
to the front as practicable

(Rev. 12/10/92)

PART 571; S 108-30

-Location of Required Motor Vehicle Lighting Equipment Multipurpose Passenger Vehicles,
Trucks, Trailers, and Buses, Of 80 Or More Inches Overall Width — Continued

Side marker lamps On each side — 1 red as far to the rear On each side — 1 red as far to the rear Not less than 15 inches, and on the

as practicable, and 1 amber as far as practicable, and 1 amber as far rear of trailers not more than 60
to the front as practicable to the front as practicable inches.

[54 F.R. 58406— December 10, 1992. Effective: December 1, 1993]

PART 571; S 108-31

(Rev. 12/10/92)

Table III. — Required Motor Vehicle Lighting Equipment All Passenger Cars and Motorcycles, and
Multipurpose Passenger Vehicles, Trucks, Trailers, and Buses, of Less Than 80 Inches Overall Width

Item

■ Passenger cars, multipurpose

passenger vehicles, trucks.

and buses

Trailers

Motorcycles

Applicable SAE standards or rec-

Column 1

Column 2

Column 3

Column 4

Column 5

Headlamps

SeeSV

[For motorcycles only, J584, April
1964. J566, January I960.]

Taillamps^

2 red

1 red

J585e, September 1977.

Stoplamps

2 red

1 red

SAE J586. February 1984.

High mounted stoplamp

1 red. for passenger cars
only

Not required

J 186a. September 1977.

License plate lamp '

1 white

J587. October 1981.

Parking lamps -

2 amber or white

None

J222, December 1970.

Reflex reflectors

4 red, 2 amber

4 red; 2 amber

3 red; 2 amber

J594f, January 1977.

Intermediate side reflex
reflectors ^

2 amber

None

J594f. January 1977.

Intermediate side marker
lamps '

2 amber

None

J592e. July 1972.

Side marker lamps

2 red, 2 amber

2 red; 2 amber

None

J592e, July 1972.

Backup lamp

1 white

None

J593C, February 1968.

Turn signal lamps '

2 red or amber: 2 amber

2 red or amber

2 amber; 2 red or
amber

SAE J588. November 1984.

Turn signal operating

None

J589. April 1964.

Turn signal flasher

None

J590b. October 1965.

Vehicular hazard warn-
ing signal operating
unit

None

J910, January 1966.

Vehicular hazard warn-
ing signal flasher

None

J945, February 1966.

[(56 F.R. 12123— March 22,1991. Effective: March 22, 1991)]
■SeeSS.l.l.lO. -See S5.1.I.1 1-12. 'See S5.5.6. •'See S5.1

(Rev. 3/22/91)

PART 571; S 108-32

Table IV. — Location of Required Equipment All Passenger Cars and Motorcycles, and Multipurpose
Passenger Vehicles, Trucks, Trailers, and Buses of Less Than 80 Inches Overall Width

Molorcycle

Headlamps

On the front, each headlamp provid-
ing the upper beam, at the same
height. 1 on each side of the verti-
cal centerline. each headlamp pro-
viding the lower beam, at the same
height, 1 on each side of the verti-
cal centerline, as far apart as prac-
ticable. See also S7.

On the front, on the vertical center-
line, except that if two are used
they shall be symetrically disposed
about the vertical centerline.

Not less than 22 inches (55.9 cm) nor
more than 54 inches (137.2 cm).

On the rear — I on each side of the On the rear — on the vertical center-
vertical centerline, at the same line except that if two are used,
height, and as far apart as prac- they shall be symmetrically dis-
ticable -. posed about the vertical centerline.

Not less than 15 inches.
than 72 inches.

On the rear — on each side of the ver-
tical centerline, at the same height,
and as far apart as practicable -.

On the rear — on the vertical center-
line except that if two are used,
they shall be symmetrically dis-
posed about the vertical centerline.

ot less than 15 inches, nor more
than 72 inches.

High-mounted One the rear, on the vertical center- Not required

stoplamp line [See S5. 1.1.27, S5.3.1.8, and

Table III], effective September I,
1985. for passenger cars only.

See S5.3.1.8 for passenger cars. Not
less than 34 inches for multipur-
pose passenger vehicles, trucks,
and buses.

License-plate lamp At rear license plate, to illuminate the At rear license pla

plate from the top or sides.

No requirement.

On the front — 1 on each side of the Not required
vertical centerline. at the same
height and as far apart as prac-

Reflex reflectors

On the rear — 1 red on each side of On the rear-

red on the vertical Not less than 15 inches, nor more

the vertical centerline, at the same
height, and as far apart as prac-
ticable -.
On each side — 1 red as far to the rear
as practicable, and 1 amber as far
to the front as practicable -.

centerline except that, if two are than 60 inches,
used on the rear, they shall be
symmetrically disposed about the
vertical centerline.
On each side — 1 red as far to the rear
as practicable, and 1 amber as far
to the front as practicable.

On the rear

Not required

No requirement.

Turn-signal lamps '

At or near the front — 1 amber on
each side of the vertical centerline,
at the same height, and as far apart
as practicable.

On the rear — 1 red or amber on each
side of the vertical centerline, at
the same height, and as far apart as
practicable.

At or near the front — 1 amber on
each side of the vertical centerline
at the same height, and having a
minimum horizontal separation dis-
tance (centerline of lamps) of 16
inches. Minimum edge to edge
separation distance between lamp
and headlamp is 4 inches.

At or near the rear — 1 red or amber
on each side of the vertical center-
line, at the same height and having
a minimum horizontal separation
distance (centerline to centerline of
lamps) of 9 inches. Minimum edge
to edge separation distance be-
tween lamp and tail or stop lamp is
4 inches.

Side marker lamps On each side — 1 red as far to the rear Not required

as practicable, and 1 amber as far
to the front as practicable.

Not less than 15 inches.

Intermediate side
marker lamps

On each side — 1 amber located at or Not required
near the midpoint between the
front and rear side market lamps.

Not less than 15 inches

Intermediate side
marker reflectors

On each side — 1 amber located at or Not required
near the midpoint between the
front and rear side marker reflec-

PART571; S 108-33

(Rev. 12/10/92)

Note: (1) The term "overall width" refers to
the nominal design dimension of the widest part
of the vehicle, exclusive of signal lamps, marker
lamps, outside rearview minors, flexible fender
extensions, and mud flaps, determine with doors
and windows closed, and the wheels in the
straight-ahead position.

This supersedes the interpretation of the term
"overall width" appearing in the Federal Reg-
ister on March 1, 1967 {32 FR 3390).

(2) Paragraph S3.1 and Tables I and III of
§571.108 as amended (32 FR 10833, Dec. 16,
1967), specify that certain lamp assembles shall
conform to applicable SAE Standards. Each of
these basically referenced standards subreferences
both SAE Standard J575 (tests for motor vehicle
lighting devices and components) which in turn
references SAE Standard J573 on bulbs, and SAE
Standard J567 on bulb sockets.

(3) Paragraph C of SAE Standard 575 states in
part: "Where special bulbs are specified, they
should be submitted with the devices and the
same or similar bulbs used in the tests and oper-
ated at their rated mean spherical candlepower."
The Administrator has determined that this provi-
sion of SAE Standard J575 permits the use of
special bulbs, including tubular-type bulbs, which
do not conform to the detailed requirements of
Table I of SAE Standard J573. It follows that the
sockets for special bulbs need not conform to the
detailed requirements of SAE Standard J567.
These provisions for special bulbs in no way
except the lamp assemblies from meeting all
performance requirements specified in Federal
Standard No. 108, including those specified in the
basically referenced SAE Standards, and in the
subreferenced SAE Standard J575.

(Rev. 12/10/92)

PART 571; S 108-34

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY

STANDARD NO. 111

Convex Cross View Mirrors on School Buses

[Docket No. 89-26; Notice 3]
RIN 2127-AD24

ACTION: Final rule.

SUMMARY: This notice amends Federal motor
vehicle safety standard No. Ill, Rearview Mir-
rors, with respect to the field-of-view around
school buses. The notice amends the standard to
require a bus driver to be able to see, either
directly or through mirrors, certain specified areas
in front of and along both sides of school buses;
to specify certain criteria for convex cross view
mirrors; and to establish test conditions designed
to ensure that the image of an object is sufficiently
clear. The amendments will improve the view
around stopped school buses, thus reducing the
risk of school buses striking student pedestrians.

Effective Date: The amendments become effec-
tive December 2, 1993.

1. Background

School buses provide an extremely safe forni of
transportation. On a vehicle-mile basis, school
buses are about four times safer than passenger
cars. Despite this outstanding safety record,
injuries and fatalities do occur, with most of them
occurring to pedestrians outside the school bus.
According to the May 1989 report by the
National Academy of Sciences (NAS), "Improv-
ing School Bus Safety," an average of 38 pedes-
trians are killed each year in school bus-related
incidents. Of these 38 pedestrian fatalities, an
average of 26 result from students being struck by
their own school bus and 12 result from being
struck by another vehicle. The NAS report also
estimated that 283 children suffer mostly minor
injuries, when they are struck by their own bus.
The NAS report concluded that since children are
at greater risk of being killed in school bus load-
ing zones (i.e., boarding and leaving the bus) than
on board school buses, "a larger share of the
school bus safety effort should be directed to

[improving the safety ot] bus stops and loading
zones."

NAS accordingly made two specific rec-
ommendations to NHTSA. First, to reduce the
number of students who are struck by vehicles
illegally passing a stopped school bus, NAS rec-
ommended the establishment of a Federal motor
vehicle safety standard requiring the installation
of stop signal arms on all new school buses. (The
agency has published Federal motor vehicle safety
standard 131, "School Bus Pedestrian Safety
Devices," which becomes effective for all new
school buses produced on or after September 1,
1992. 56 FR 20363, May 3, 1991). Second, to
reduce the number of children who are struck by
their own school bus, NAS recommended that
NHTSA "reexamine its standards for cross view
mirrors to determine whether current specifica-
tions can be modified to give the driver a better
view of the areas in front of and immediately
beside the bus."

Federal motor vehicle safety standard No. Ill,
Rearview Mirrors, (49 CFR 571.111) currently
requires each school bus that is not a forward
control vehicle, i.e., a transit style bus, to have an
outside cross view mirror of a specified size and
shape (S9.2), "mounted so as to provide the
driver a view of the front bumper and the area in
front of the bus" (S9.2(b)). The standard also
requires each school bus to have an outside rear-
view minor of unit magnification (i.e., flat mir-
ror) on each side of the bus, to provide the driver
with a view to the rear along both sides of the
bus (S9.1). In addition to meeting the require-
ments in Standard No. Ill, school buses are
required by nearly every State to be equipped
with additional mirrors, particularly cross view
mirrors.

As noted earlier, an average of 26 students are
killed each year and 283 are injured each year
after being struck by their own school bus. These

PART 571: Slll-PRE-29

incidents are rare. Nevertheless, the potential for
such tragedies is actually quite large because
every time a student gets on or off a school bus,
there is a chance that the driver may not see that
student in the proximity of the bus. According to
the 1989 NAS report, of the 26 students killed as
pedestrians each year "tv/o-thirds are struck by
the front of the bus and one-third by the rear of
the bus, usually the rear wheels." A review of
specific incidents reveals that the fatalities
occurred because the driver did not see the child
in front of or to the side of the bus. In many
cases in which the child was struck by the bus's
rear wheels, the bus had already left the bus stop.
In these cases, the children were typically running
after the moving bus and fell under the rear
wheels. Such incidents cannot be totally avoided
through changes to the mirror requirements, since
driver error may be a significant cause of many
such incidents. In addition, once the school bus is
moving, the driver must focus on other driving
actions in addition to looking into the mirror sys-
tems to check for students around the outside of
the bus. However, to reduce the likelihood of stu-
dents being struck by their own bus in the school
bus loading zone, the agency has conducted this
rulemaking to improve the means available for
the school bus driver to detect their presence
around the stopped bus.

The Kansas Department of Transportation con-
ducts an annual nationwide "School Bus Loading
and Unloading Survey" which reviews every
school bus pedestrian fatality. This study confirms
that a significant, although decreasing, number of
pedestrians are killed by school buses. The Kan-
sas data indicate that the number of pupils killed
nationwide in school bus loading zones was 45 in
1985. 42 in 1986, 32 in 1987, 16 in 1988. 17 in
1989, and 18 in 1990. The agency believes that
the decrease in the number of school bus loading
zone fatalities is due to a combination of factors,
including the use of more and better mirtors, the
increased use of stop signal arms, and improved
school bus driver and student training. Despite
this trend, this type of incident remains the most
common way students are killed in school bus-
related incidents. Therefore, the agency has con-
ducted this rulemaking to upgrade Standard No.
Ill's mirtor requirements to reduce further the
potential for fatalities and injuries to students by
school buses.

II. Previous Agency Action
A. Advance Notice of Proposed Rulemaking

(

On December 17, 1989, NHTSA published an
Advance Notice of Proposed Rulemaking
(ANPRM) announcing the agency's interest in
measures designed to prevent children from being
struck by school buses during and after loading
and unloading operations. 54 FR 53127. The
ANPRM asked questions about pedestrian safety
around school buses to assist the agency in decid-
ing whether to pursue rulemaking on cross view
mirror systems and other devices designed to pro-
tect pedestrians from being struck by the school
bus (e.g., crossing control arms, sensors, or video
monitors). Among the issues presented were: (1)
The safety need for amending the mirror require-
ments or for requiring additional equipment such
as crossing control arms; (2) the need to develop
performance requirements to ensure that a driver
sees or is otherwise aware of pedestrians in
school bus loading zones; (3) the costs of requir-
ing different types of or additional mirror systems
and of requiring other types of equipment; and (4)
the potential impact of new requirements on
school bus users currently in compliance with
FMVSS No. Ill and on cuiTent State laws that ^

would differ from the Federal requirements that V

might be proposed.

The agency received comments from State and
local governmental organizations, school bus
manufacturers. miiTor and other equipment manu-
facturers, associations, and individuals. The com-
menters generally agreed that measures should be
taken to reduce the number of children struck by
school buses and to improve the view of school
bus drivers around the school bus while it is in
the school bus loading zone. Commenters also
addressed other issues raised in the ANPRM,
including the need for devices other than mirror
systems for increasing school bus drivers" aware-
ness of children outside of school buses, the bene-
fits from training programs, and the costs of the
equipment addressed in the ANPRM.

B. Notice of Proposed Rulemaking

Based on the comments received to the
ANPRM and the results of NHTSA research con-
ducted by the Vehicle Research and Test Center
(VRTC) on school bus miiTor performance ^
("Ergonomic Research on School Bus Cross f
View Mirror Systems" DOT-HS-807-676, ^-

PARI 571; SIll-PRE-30

August 1990), the agency published a Notice of
^ Proposed Rulemaking (NPRM) in the Federal
A Register. 56 FR 20171. May 2, 1991. The
^^ agency had two primary objectives in publishing
the NPRM: (1) To improve the capability of
school bus drivers to see specified critical areas
in front of and alongside of school buses in
school bus loading zones, and (2) to propose a
performance-oriented standard that would replace
the existing requirements that prevented certain
new convex cross view mirror designs. The
NPRM proposed specific performance require-
ments to Standard No. 1 1 1 to ensure that a seated
school bus driver could see, either directly or
through mirrors, certain specified areas in front of
and alongside of a school bus. The proposal
specified certain criteria for convex cross view
mirrors and proposed establishing test conditions
to ensure that the image of an object in a mirror
had sufficient clarity. The NPRM also announced
the agency's decision not to proceed further with
rulemaking to require school buses to be equipped
with other devices such as crossing control arms,
sensors, or video monitors.
The agency received comments in response to
^ the NPRM from State and local organizations,
^ school bus manufacturers, equipment manufactur-
ers and suppliers, associations, and other
organizations. The commenters generally sup-
ported the proposal but provided suggested modi-
fications to various portions of it. The agency has
considered all the comments in developing the
final rule. The commenters' significant points are
addressed below, along with the agency's
response.

III. Agency Decision

A. General Considerations

Based on the docket comments and other avail-
able information, NHTSA has decided to amend
Standard No. 1 1 1 with respect to the field-of-view
around school buses. This final rule amends the
standard to require a bus driver to be able to see,
either directly or through mirrors, certain speci-
fied areas in front of and along both sides of
school buses; to specify certain criteria for convex
cross view mirrors; and to establish test condi-
tions designed to ensure that the image of an
\ object is sufficiently clear. Standard No. 1 1 1 is

^ also amended to include detailed test procedures

to ensure that a school bus provides adequate

field-of-view around a stopped school bus, thus
reducing the risk of school buses striking student
pedestrians.

Among the issues addressed in this notice are
the field-of-view performance requirements; the
placement and characteristics of cylinders rep-
resenting the field-of-view requirements; school
bus mirror systems including both flat driving
mirrors and convex cross view mirrors; specific
concerns about convex cross view mirrors includ-
ing accommodation distance, discontinuities in the
surface's slope, adjustment, image quality, and
labeling information about their proper use; test-
ing procedures; and the rulemaking's anticipated
costs and effective date.

While the final rule essentially adopts the
provisions proposed in the NPRM, the final rule
does contain several changes as compared to the
proposal. Among the more important changes are
that the field-of-view requirements include the
area near the rear left side of the bus, that the test
procedure specifies the stop signal arm be in the
retracted position and the front entry door be
closed during the testing, that determining the
minimum radius of curvature of a mirror be based
solely on the distance from the driver's eye loca-
tion to the mirror surface, that the message about
the convex mirror be placed inside the vehicle
and be expanded to be more informative, and that
testing is allowed at any point within a specified
area forward of the 25th percentile adult female
driver's eye location, instead of four specific
points relative to the eye location.

B. Field-of-view requirements

As explained above. Standard No. 1 1 1 cur-
rently specifies that each school bus must have an
outside rearview mirror of unit magnification (i.e.,
a flat mirror) on both sides of the bus that "pro-
vides the driver a view to the rear along both
sides of the vehicle * * *" In addition, each
school bus, except for forward control vehicles,
must have one convex cross view mirror that
complies with detailed specifications and
"provide(s) the driver a view of the front bumper
and the area in front of the bus."

The NPRM proposed requiring that a school
bus driver be able to see, directly or through mir-
rors, test cylinders representing smdents in critical
areas around the school bus. To effectuate this
goal, each school bus would be required to have
mirror systems on both the left and right sides of

PART 571: Slll-PRE-31

the school bus — a set of driving mirrors to view
the sides of the bus and areas to the rear of the
bus, and a set of convex cross view mirrors to see
specified areas at the left front comer of the bus,
in front of the bus, and along the right side of the
bus. Areas viewable along the bus's right side via
the two mirror systems would be required to
overlap, as would the areas visible along the bus's
left side. Along each side, the driver would be
provided with a view of the ground from the front
bumper forward, along the sides of the bus, and
extending at least 200 feet rearward from the mir-
ror. The NPRM proposed that the driver must be
able to see the entire top surface of the cylinders
placed at critical locations around the bus. Com-
pared to the current requirements for school bus
mirrors, the proposed field-of-view requirements
would extend the areas which must be visible,
provide field-of-view requirements applicable to
any school bus configuration, and provide greater
objectivity. The NPRM asked whether the pro-
posed field-of-view requirements, as expressed
through the placement of cylinders, would reason-
ably represent the locations at which school bus
pedestrians need to be seen by the driver during
school bus loading and unloading.

With respect to the field-of-view approach, the
commenters, including the National School
Transportation Association (NSTA), Transport
Canada, Mirror Lite, Arizona DOT (Arizona), and
the Washington State Superintendent of Public
Instruction (Washington State) believed that this
approach was appropriate. No commenter opposed
the proposed approach. Washington State com-
mented that the proposal would provide a realistic
performance standard for mirrors. Transport Can-
ada believed that there was a need to improve the
field-of-view for school bus drivers and to pro-
vide an objective measurement method for all
mirrors on school buses.

After reviewing the comments, NHTSA con-
cludes that establishing performance-based field-
of-view requirements for school bus mirror sys-
tems is reasonable and appropriate. Such an
approach will reduce the risk of injury to student
pedestrians, while affording mirror and school bus
manufacturers and users greater flexibility.

C. Test Cylinders
1 . Cylinder Placement £

As for the placement of test cylinders used to
represent student pedestrians, the NPRM proposed
that they be located at specified locations near the
bus's front wheels, front bumper, locations for-
ward of the bus, near the front right and left
wheels, and near the rear right wheel. These pro-
posed locations were based on narratives in the
NAS report and docket comments, the VRTC
report, the State of Ohio's regulation, and the
Eleventh National Conference of School
Transportation. Nevertheless, unlike Ohio's regu-
lation and the Eleventh National Conference's
specification, NHTSA proposed specific locations
and test procedures for showing compliance with
the requirements. In requesting comments about
whether the proposal reasonably represented loca-
tions where student pedestrians are struck by
school buses, the agency expressly asked whether
the area near the left rear wheels poses a safety
problem.

While commenters generally supported the pro-
posed locations for the test cylinders, some com-
menters addressed whether cylinders should be L
placed at certain additional locations around the V^
school bus.

Several commenters, including the National
PTA, Blue Bird, Mirror Lite, the West Virginia
Department of Education (West Virginia), NSTA,
Washington State, and Arizona, stated that a view
down the left side of the bus was important. No
commenter stated that a view of the left side of
the bus was unnecessary. Mirror Lite cited fatali-
ties in Michigan and Texas to support the view
that incidents along the bus's left side, although
uncommon, do occur. In recommending that the
field-of-view be the same for both sides of the
bus. Mirror Lite commented that the cost of such
a requirement would be the same and that drivers
prefer mirrors to be matching on the right and
left, rather than having two different fields-of-
view.

After reviewing the comments, NHTSA has
concluded that the field-of-view on the left side
of the bus should be extended back to the ground
near the left rear wheel. While the agency

PART 571- Slll-PRE-32

acknowledges that children are infrequently struck
^ near the left side of the bus, the agency notes that
B such incidents do occur. Accordingly, by requir-
^ ing test cylinders to be placed by the left rear tire,
the amendments will increase the likelihood that
the new school bus mirror requirements can pre-
vent these incidents as well.

The agency conducted mirror evaluations on
both conventional and transit-style school buses
indicating that left side mirror systems designed
to meet the proposed field-of-view requirements
for the left front comer and the front of the
school bus would also be able to provide a view
of test cylinders located at least six feet to the left
of the left rear wheel without any adjustments to
the mirrors. Additionally, based on the agency's
review of current mirror systems, the agency
anticipates that the mirrors on the left and right
side of the bus will be symmetrical (i.e., a mirror
designed to view the right side of the bus will
also be able to view the left side of the bus when
mounted on the left front of the bus). Based on
the above, the agency has modified the final
requirements to include additional test cylinders
located one foot and six feet to the left of the left
^ rear axle.

^ Although a cylinder located twelve feet to the

right of the rear axle on the bus' right side is
required to be visible, NHTSA believes that is not
necessary to require that a test cylinder located
twelve feet to the left of the rear axle be visible.
For a school bus on the side of the road in a load-
ing zone, a cylinder located twelve feet to the left
of the left side of the bus would represent a stu-
dent standing a full traffic lane from the bus. The
agency believes that it is unlikely that a student
would be in such a position when the school bus
starts to depart from the loading zone. In local-
ities where school buses stop in a traffic lane, a
cylinder located twelve feet from the left side
would represent a child on the other side of the
street on a two lane street.

During the course of its mirror evaluations, the
agency observed that, in some cases, the cylinders
at the left rear axle of the school bus were either
partially or fully blocked from view by the
extended stop signal arm. Visibility depended on
the bus body type and the location of the stop sig-
nal and the left side cross view mirror. In con-
k trast, the test cylinders were visible when the stop

' arm was retracted. The agency also noted that the

test cylinders at the right rear axle were either

partially or fully blocked by the door when an
outward-opening front entry door was open.
Based on these observations, NHTSA has decided
that the test procedure will specify that the stop
signal arm be in the retracted position and the
front entry door be closed. This procedure recog-
nizes that school bus drivers must close the door,
which retracts the stop signal arm, and then view
the mirrors to ensure that no students are in dan-
ger around the bus before the school bus leaves
the loading zone. If the driver attempted to view
the areas around the bus before closing the door
and retracting the stop signal arm, the stop signal
arm would also block the driver's view of the
road, thus impairing many driving decisions.

Blue Bird commented that placing test cyl-
inders J, K, and L on a plane one foot away from
the bus would be more appropriate than the pro-
posed two foot distance because the two foot
location of cylinder L would provide only limited
visibility adjacent to the rear wheel. (The agency
notes that cylinder L in the NPRM is cylinder N
in the final rule.) Blue Bird commented further
that a one foot distance from the most outboard
edge of the front bumper for cylinders J and K
would help ensure adequate visibility near the
front wheels. The agency agrees with this com-
ment and has revised the location requirements
accordingly.

Blue Bird commented that there were no pro-
posed requirements for the visibility of cylinder
M. which is located six feet from the right side
of the bus at the rear wheel. (The agency notes
that cylinder M in the NPRM is cylinder O in the
final rule.) That was an oversight in the NPRM,
and a provision about cylinder M is included in
the final rule's requirements for mirror System B.

NSTA suggested that a test cylinder be added
to the area directly to the rear of the service door.
After conducting mirror evaluations, the agency
has concluded that locating a test cylinder to the
rear of the service entry door would not be nec-
essary since mirror systems that provide a view of
cylinders K and L would also provide a view of
the rear side of the service entry door.

Transport Canada believed that because it is
theoretically possible for blind spots to exist in
some areas between cylinders in front of the bus,
NHTSA should specify areas whose perimeters
would be defined in terms of cylinder locations
that must be seen, rather than simply the cylinders
themselves. In the course of this rulemaking.

PART 571; SIll-PRE-33

agency staff have evaluated a variety of mirror
systems on both conventional and transit-style
school buses. In all cases where the test cylinders
could be seen and identified in a mirror system,
the full ground areas around and between the cyl-
inders could be seen. The agency notes that while
a blind spot could occur when looking at a single
mirror, such blind spots were eliminated when
viewing the entire mirror system. Although it
might be theoretically possible for a blind spot to
exist between test cylinders, the agency believes
such situations would be extremely rare.

The New York State Senate Committee on
Transportation (New York) believed that the
requirements in S9.2 for the System A driving
mirrors on the right side of the bus should have
a field-of-view that extends twelve feet out from
the side of the bus, not just two feet out, to pro-
vide the driver with adequate warning time that a
pedestrian contact is imminent. The agency notes
that the requirements in S9.2 are primarily for the
driving mirror system which must include at least
one mirror of unit magnification. Such a mirror
could not be adjusted to provide a view that
included the side of the bus and a point twelve
feet out from the rear axle line unless it were
unusually large in size. Yet, such a large mirror
would create its own large blind spot. The
requirements for System B convex cross view
mirrors, which are pedestrian detection mirrors,
already provide the seated driver with information
about individuals that may be as close as twelve
feet from the side of the school bus. Accordingly,
because the mirror that would be necessary to
accommodate New York's request would have
safety trade-offs and provide redundant perform-
ance, NHTSA has decided not to change the pro-
posed requirements for S9.2 in this rule.

2. Cylinder Dimensions

The proposed provisions about the test cyl-
inders used to represent student pedestrians
specify that they be one foot high and one foot
in diameter and require that their entire top sur-
face be visible. The agency based this proposal on
the VRTC report's recommendation that measure-
ments be made near ground level and on accounts
in the docket explaining that children struck by
school buses were low to the ground. Addition-
ally, nairatives in the 1989 NAS report and the
mirror requirements from Ohio support the con-
cept of using some sort of three-dimensional rep-

resentation of a small child. An exception to the
one foot requirement would be that the cylinder
placed twelve feet to the right of the rear right M
wheel, would be three feet high and one foot in ^
diameter. The agency believed that this cylinder
needed to have such dimensions to evaluate elon-
gation.

Several commenters, including NSTA, Mirror
Lite, and Thomas Built, supported the proposal to
require the driver to view the cylinder's entire
top. NSTA commented that this requirement
would help ensure that the driver is provided with
a complete enough image to enable the driver to
identify student pedestrians in the mirror. After
evaluating new generation mirrors and some older
mirrors which they consider to be "marginal,"
Thomas Built determined that only the new mir-
rors could meet the cylinder viewing require-
ments. This led Thomas Built to conclude that
viewing the top of the cylinders is a satisfactory
requirement.

A few commenters were concerned that the
proposed test cylinder was not adequate for ensur-
ing that all of the critical areas of the ground
would be visible. Washington State believed that
by focusing on the cylinder's top, the proposed -
visibility test may be inadequate because it T^
ignores contact at the ground level. Lo-Mar and
Blue Bird believed that the view of the ground is
not ensured through the use of one foot high cyl-
inders. Accordingly, these commenters rec-
ommended that cylinders be replaced with one
foot diameter flat discs.

After considering the comments about test
object's dimensions, NHTSA has concluded that
one foot tall cylinders better represent real-world
situations than flat discs. In the majority of load-
ing zone incidents, children struck and killed by
school buses were either standing or bending
over, according to the Kansas Department of
Transportation's "1989 School Bus Loading &
Unloading Survey." Therefore, the agency
believes that most students who are struck by a
school bus are at least one foot above the ground.
Even children who have fallen are above ground
level because their body thickness at their head or
torso is at least six inches. If children have fallen,
the agency expects that they will be attempting to
get back up. which also adds height. The agen-
cy's mirror system evaluations further indicate .

that a three dimensional object such as the one
foot tall test cylinder more accurately represents

PART 571; SlII-PRE-34

real-world situations than a flat disc. In addition,
the cylinder facilitates testing by providing a
^ more practicable means for demonstrating the
W ability of mirrors to view areas around the outside
of the bus. The three dimensional cylinder also
makes the relative image quality easier to
ascertain.

Mirror Lite commented that the cylinders
should be of a readily available design to facili-
tate testing and to avoid discouraging manufactur-
ers from conducting the test. This view led Mirror
Lite to recommend using bright orange 18" traf-
fic cones. Washington State requested that along
with establishing a requirement for the manufac-
ture of new buses and equipment, the standard
should also provide an ongoing performance
standard for the end user (e.g., mechanics and bus
drivers). Similarly, Ann Arundel County (Mary-
land) Public Schools explained that they were
interested in incorporating the test cylinder grid
into its training program.

As for Mirror Lite's comment about an 18"
traffic cone, NHTSA believes that such a device
is too tall to represent a child who may be bend-
ing over or has fallen down. The agency never-
^ theless agrees with Mirror Lite that having a read-
W ily available test object will assist States and local
school districts in evaluating mirrors and training
school bus drivers. The agency believes that the
one foot cylinder is a reasonable size and shape
that should be easy to obtain or fabricate. The
agency also notes that the one foot test cylinder
is only required for compliance test purposes, and
that anyone desiring to build a test lane can sub-
stitute another test object when conducting
evaluations or training.

While generally supporting the performance
requirements for mirror System B, Blue Bird rec-
ommended an alternative requirement which
defined the bounds of specific geometric areas on
the ground outside the school bus which would
have to be seen. Among Blue Bird's criticisms of
the proposal were the use of a cylinder rather
than a disc, the need to reduce the distance
between the test cylinders and the bus to one foot,
the need to include cylinder M in the performance
requirements, and the need to include visibility
requirements for the left side of the bus. Since all
of these items have been addressed above and all
k but the use of a disc were adopted, the agency
" does not believe Blue Bird's recommended alter-
native is necessary.

3. Cylinder Color

The NPRM proposed that the test cylinders
be a color which provides a high contrast with the
surface on which the bus is parked. According to
the VRTC report, such a contrast would facilitate
compliance testing. While the proposal did not
specify a particular color, the agency requested
comments about what color would provide a high
contrast with the ground and whether a given
color should be specified.

Several commenters addressed the appropriate
color and design of the test objects. NSTA sug-
gested that rather than having a high contrast
color, the cylinder should be a color that blends
into the surroundings, believing that visibility
becomes a problem when a child blends in with
the surroundings (e.g., the bus itself, pavement).
New York favored replacing the cylinders with
two dimensional cutouts of children and adults
with colors that are representative of clothes typi-
cally used by school children or adults.

Other commenters believed that the test cyl-
inder should be a bright color. Mirror Lite rec-
ommended using bright orange traffic cones.
Thomas Built explained that its mirror tests are
conducted using bright colored cylinders, e.g.,
safety orange sides with lime green tops and
black letters. R&R Research recommended that to
make the test procedure less vague, the color of
the test cylinders should "be specified either
quantitatively (i.e., the percent contrast) or quali-
tatively by specifying the color of the cylinders."

After reviewing the comments and its own mir-
ror evaluations, NHTSA has decided that the test
cylinder must provide a high contrast with the
surface on which the bus is parked. The agency
believes that having such a high contrast will
facilitate compliance testing. Nevertheless, the
agency has determined that it would be inappro-
priate and unnecessary to specify a given color
for the test cylinder. The agency has no informa-
tion to suggest that one color would be more
appropriate for a test cylinder than any other
color. The agency believes that specifying a sin-
gle color would complicate the standard without
providing any significant corresponding benefits.

D. School Bus Mirror Systems

1. General

Standard No. 1 1 1 currently requires school
buses to be equipped with two types of mirror

PART 571; Slll-PRE-35

systems: (1) An outside rearview mirror of unit
magnification ("flat mirror") of not less than 50
square inches of reflective surface on each side of
the bus; and (2) one convex cross view mirror. In
practice, buses are equipped with a flat driving
mirror on each side of the bus, two or more con-
vex cross view mirrors, and typically at least one
supplemental convex mirror mounted near each
flat mirror and designed to serve as an additional
driving mirror. Convex driving mirrors are typi-
cally about four inches in diameter and have a
radius of curvature (ROC) greater than 35 inches.
These larger radii of curvature mirrors have much
greater image clarity than the convex cross view
mirrors mounted on the front of the bus and
therefore can safely be used as driving mirrors.
All mirror systems are used by drivers to see stu-
dents in the loading zone around buses, although
the flat miiTors and the supplemental convex driv-
ing mirrors are primarily designed to serve as
driving mirrors.

The NPRM proposed to modify the current
requirements for both types of mirror systems so
that each school bus would be equipped with two
mirror systems on each side of the bus: (1) A sys-
tem that includes flat driving mirrors of unit mag-
nification and optional convex driving mirrors
(designated as "System A") and (2) a system
that consists of convex cross view mirrors for stu-
dent detection during loading and unloading (des-
ignated as "System B"). The areas viewable
along both sides of the bus via the two mirror
systems would be required to overlap on each
side, providing the driver with a view of the
ground in front of and along both sides of the bus
and extending at least 200 feet rearward from the
driving mirror. Because the agency recognized
that most current driving mirror systems on
school buses consist of both a flat mirror and a
convex mirror, the NPRM included language that
"one or more mirrors" could be used to meet the
requirements of S9.2 for System A mirrors.

2. Driving Mirrors — System A Mirrors

As for System A mirrors, the NPRM proposed
making the current requirements for such mirror
systems more objective and expanding the field-
of-view to include a larger area. Specifically, the
NPRM proposed amending section S9.2 to require
that the driver have a view at least 200 feet to the
rear and at least two feet to the right of the right
side of the bus. The NPRM explained that the

proposed requirements reflect the findings of the
1 1 th National Conference on School Transpor-
tation and accounts in the NAS report and docket
that a significant number of incidents occur by
the right rear wheels of school buses.

In responding to the NPRM's proposal about
System A mirror systems, several commenters,
including Mirror Lite, Thomas Built, Transport
Canada, and Blue Bird, appear to have misunder-
stood the proposed requirements of S9.2. Based
on their comments, it appears that they believe
the system's flat mirror portion by itself would
have to comply with the requirement that the
view of the "area of the ground which extends
rearward from the mirror surface [must be] not
less than 200 feet." The agency wishes to clarify
that the flat mirror by itself need not comply with
S9.2. The proposed requirements were for a
"mirror system" (emphasis added) which could
include both a flat mirror and a convex mirror.
Accordingly, to comply with S9.2, it is permis-
sible for the convex portion of the mirror system
to provide some portions of the required field-of-
view.

The agency believes that it is unnecessary to
expressly require the installation of a convex mir-
ror for the driving mirror system. Since the pro-
posed revisions to Standard No. 1 1 1 are perform-
ance-oriented, not design-oriented, manufacturers
can choose whatever mirror system they believe
is best. Avoiding unnecessary restrictions facili-
tates the introduction of future technological
improvements in mirror systems.

Blue Bird suggested modifying S9.2(c) by
establishing specified zones along both sides of
the bus which would have to be viewable to the
seated driver. As explained in the section on test
cylinders, the agency believes that establishing
field-of-view requirements through test cylinders
at specific locations around a school bus provides
a more realistic simulation of real-worid school
bus operations than establishing geometric zones.

Blue Bird also commented that establishing
minimum permissible radii for convex mirrors
used in proposed mirror System A could be det-
rimental to the performance requirements being
proposed. The agency notes that neither the
NPRM nor the final rule included provisions
about minimum radii of curvature for System A
mirrors. The same is true for System B mirrors.

PART 571; Slll-PRE-36

3. Convex cross view minors — System B Mirrors

a. General. S9.2(a) of Standard No. Ill cur-
rently contains detailed specifications about the
characteristics of convex cross view mirrors,
including minimum and maximum permissible
radii of curvature, minimum surface areas, and
restrictions for convex mirrors with non-uniform
radii. The current standard only requires one con-
vex cross view mirror.

The NPRM proposed that a cross view mirror
system (System B) be provided on both sides of
a school bus to ensure that seated drivers have a
complete view of all critical areas in front of and
along both sides of the bus that are not within
their direct field-of-view. The NPRM also
included a requirement that "[T]he view of the
ground provided at the driver's eye location by
system B shall overlap with the view of the
ground provided by system A." The agency pro-
posed to delete the current specifications for con-
vex mirrors, believing that this action would per-
mit States and local school districts to use a wider
variety of mirrors.

The NPRM addressed several subissues about
convex cross view mirror characteristics, includ-
ing accommodation distance (i.e., the distance at
which people can focus on images in mirrors),
discontinuities in the mirror surface's slope,
adjustment, informational labeling, and image
quality.

In addition to general questions about convex
cross view mirrors, the agency specifically asked
about whether a minimum permissible radius of
curvature should be specified, whether convex
cross view mirrors should be used for driving
purposes, and whether the upper portion of con-
vex mirrors should be cut off or blackened out to
reduce the amount of glare reflected into the driv-
er's eye.

All commenters supported using convex cross
view mirrors to view areas outside of school
buses. Commenters also addressed specific points
about particular mirror systems. Mirror Lite
believed that wide-angle cross view mirrors are
better than multiple conventional mirrors because
having multiple mirrors would result in confusion
as to which mirror is showing what image.

Several commenters, including Thomas Built
and Blue Bird, stated that in practice, convex
cross view mirrors are used for driving purposes.
Thomas Built and Blue Bird commented that cer-

tain convex cross view mirrors should not be used
as driving mirrors. These comments are addressed
later in this preamble in the section discussing an
instructional message for the proper use of con-
vex cross view mirrors.

Several commenters responded to the agency's
question in the NPRM about cutting off or black-
ening out the cross view mirror's upper portion.
The Arizona DOT opposed cutting off or blacken-
ing out any portion of the convex cross view mir-
ror, believing that all portions of the mirror pro-
vide some benefit if properly adjusted and used.
In contrast, Washington State, the Tennessee
DOE, Florida, the Sloan Company, and Mirror
Lite believed that the top portions of convex cross
view mirrors serve no useful purpose and should
be eliminated. Mirror Lite stated that the "market
place has determined the upper portion of the
mirror is of no value and may be a distraction to
the driver."

Notwithstanding the comments favoring the
elimination of the top portion of convex cross
view mirrors, NHTSA believes that there is no
conclusive information to support this approach.
Additionally, there is no information available for
determining what specific areas of mirrors should
be cut off or blackened out. This type of require-
ment would also make the standard more design
restrictive than the agency believes is desirable. In
addition. Mirror Lite's claim that the "market-
place" has determined the need for blackening
out such mirrors does not appear to be accurate,
since several convex mirrors without blacked-out
areas are apparently being successfully sold in the
marketplace. However, if certain mirror areas are
found to be inefficient, then the agency antici-
pates that the marketplace will make judgments
on the efficacy of various mirror systems and that
those judgments will be reflected in future mirror
designs. Since no information was produced to
suggest that the upper portions of cross view mir-
rors were dangerous to a driver's view of pedes-
trians, the agency has decided not to establish
limitations on the field-of-view coverage provided
by a cross view mirror. The agency believes that
individual State and local school districts are
capable of evaluating mirror systems that meet
these standards and selecting those which best
meet their needs, including, if they so chose, mir-
rors from which the top portions have been elimi-
nated.

PART571;Slll-PRE-37

b. Accommodation distances. The NPRM pro-
posed a new provision that would require that the
distance from the center of each convex cross
view mirror to the center point of the driver's eye
location, plus one-half the smallest radius of cur-
vamre of the mirror surface be at least 39 inches.
The agency based this proposal on the VRTC
report's finding about accommodation distances,
i.e., the finding that older people have greater dif-
ficulty focusing on nearby objects, especially in
convex mirrors with small radii of curvature.
According to the VRTC report, if the distance
between the driver and the image in the mirror is
less than 40 inches, drivers over 40 years old may
see a blurred image.

Several commenters supported the 39 inch
accommodation distance, believing that such a
requirement is feasible. Thomas Built, R & R
Research, and Mirror Lite stated that the 39 inch
distance between the driver seat to the mirror is
acceptable for most currently-produced buses.
Nevertheless, R & R Research, along with NSTA,
questioned whether transit type school buses
could be equipped to comply with the 39 inch
requirement. Neither NSTA nor R & R Research
provided any specific information to support their
concerns about transit buses.

Blue Bird disagreed with the 39 inch require-
ment, stating that it would be difficult to measure
accurately and might hinder mirror performance
and innovations. Blue Bird opposed having
restrictions on the mirror's location, claiming that
the agency does not restrict the locations of other
bus components such as gauges, switches, and
lights.

Based on the available information, including
the agency's evaluations of the comments and
various mirror systems, NHTSA has decided to
adopt the proposed accommodation distance
requirement with certain modifications. In
evaluating various mirror systems on both
conventional and transit-style school buses,
NHTSA has found that these mirrors are always
capable of complying with the proposed 39 inch
requirement of S9.3(b)(2) when mounted at loca-
tions consistent with the mirror manufacturers'
recommendation. The agency also notes that the
concerns expressed by NHTSA and R&R
Research about transit-style school buses not
being able to meet such a requirement were not
shared by the school bus and mirror manufactur-
ers commenting on this issue, all of whom stated

that the requirement could be met. Blue Bird did
not claim that the proposed 39 inch requirement
could not be met, only that it would be difficult *
to measure accurately. Also, Blue Bird appears to \
disagree with the proposed requirement on a
philosophical basis, i.e., since NHTSA does not
establish restrictions on the location of other
components of the bus used during its operation.

In evaluating the proposal, NHTSA has meas-
ured the distances from the driver's eye location
to the mirror surface on a number of school
buses, including transit style buses, and has found
it to be a straight-forward task that gets easier the
more it is done. The aspect of the measurement
that required the most effort was establishing the
line of sight through a window and then measur-
ing that line. The use of standard tape measures,
one used to measure the distance from the mirror
to the window and the other to measure the dis-
tance from the window to the eye location,
worked well for establishing the line of sight and
measuring it. The thickness of the window was
then added to the measured distances. A more
elaborate test setup could be established using a
laser or high intensity light beam to establish the
line of sight. Based on the agency's experience in ^
measuring mirror distances, the degree of B
accuracy is not that critical since all of the mirror ^—
distances were well over 39 inches.

However, NHTSA agrees with the commenters
that detennining the minimum radius of curvature
of a mirror may be a difficult and time consum-
ing task. Accordingly, the agency has modified
the final requirement so that the eye accommoda-
tion distance is based solely on the distance from
the driver's eye location to the mirror surface.

The proposed requirements in S9. 3(b)(2) have
been modified to read as follows in this final rule:
"Each mirror shall be located such that the dis-
tance from the center point of the eye location of
a 25th percentile adult female to the center of the
mirror surface shall be at least 37.5 inches." To
repeat, the proposed requirement was for the dis-
tance from the center of each convex cross view
mirror to the center point of the driver's eye, plus
one-half the smallest radius of curvature of the
mirror surface, to be at least 39 inches. While the
proposal's provision about adding "one-half the
smallest radius of curvature" to the distance from
the driver's eye to the center of the mirror is no ,
longer expressly part of the specified measure- \^^
ment, the agency derived the 37.5 inch distance

PART 571; Slll-PRE-38

in this final rule using the proposed combination
of distance between the driver's eye and the mir-
ror and one-half the radius of curvature of the
mirror.

The 37.5 inch minimum was derived as fol-
lows. Of all the minors used in the VRTC report,
the smallest radius of curvature (and thus the one
with the poorest image quality) was 3.41 inches.
Assuming that the design radius of curvature of
future mirrors would not be less than 3 inches,
then one-half of that radius of curvature would be
1.5 inches. Subtracting 1.5 inches from the 39
inch proposed requirement leaves 37.5 inches.
The final rule accordingly accounts for accommo-
dation distances in worst case situations, just as
the proposal did, but simplifies the calculation.

NHTSA disagrees with Blue Bird's comment
that mirror location should not be regulated
because the location of other components (i.e.,
gauges, switches, and lights) in the bus are not
regulated. The agency believes that to ensure the
safety of student pedestrians, the images in school
bus mirrors, particularly convex mirrors, cannot
be blurred for any driver. That same level of con-
cern is not necessary for clearly seeing a gauge
or switch, since seeing such devices is not as
critical for student safety as viewing a mirror sys-
tem. Also the inherent nature of convex mirrors,
which reduce the size and elongate the image of
the reflected object, make mirror images more
difficult to see and use. By contrast, the task of
identifying gauges and switches is comparatively
straightforward.

Arizona DOT commented that school buses
should be equipped with forward mount driving
mirrors on the left side, in lieu of the low mount
driving mirrors currently being used by many dis-
tricts. Arizona stated that this requirement "is
needed in order for the mirror to be at least 39"
from the driver's eye." NHTSA notes that
Arizona appears to have misinterpreted the provi-
sion's applicability, because the minimum
accommodation distance applies only to convex
crossview (System B) mirrors, not to driving
(System A) mirrors. Although the Arizona com-
ment is related to driving mirrors, instead of the
cross view mirrors, it illustrates that different
cross view mirror mounting locations may be nec-
essary on some types of school buses to meet the
accommodation distance requirement.

c. Discontiimities in a mirror surface's slope.
Standard No. 1 1 1 currently prohibits discontinu-

ities in a mirror surface's slope. The NPRM pro-
posed retaining this requirement, but redesignating
h S9.3(b)(3). The proposal explained that
prohibiting mirror discontinuities would prevent
mirrors in which the slope or surface of the mir-
ror was concave, thus protecting against poor
image clarity.

All those commenting on this issue, i.e., NSTA,
Mirror Lite, Thomas Built Buses, and New York
State, agreed that retaining the current prohibition
on mirror discontinuities is necessary. Accord-
ingly, the final rule adopts this provision.

Mirror Lite suggested that the agency use the
term "diminishing image" instead of "distor-
tion" to describe the image quality provided by
cross view mirrors. It stated that distortion is a
flaw in the mirror surface that can be found in
any type of mirror. After reviewing the comment,
the agency agrees with Mirror Lite and has
decided to u.se the phrase "image clarity" rather
than "distortion" in the preamble. Nevertheless,
the agency notes that this term is not in the regu-
latory test.

d. Mirror supports and adjustment. Standard
No. 1 1 1 currently requires each flat mirror and
each convex cross view mirror to be installed
with a stable support. The NPRM proposed that
each convex cross view mirror "be installed with
a stable support designed to dampen vibration."
This requirement is intended to ensure a clear and
properly focused image by preventing mirrors
from vibrating unreasonably and by reducing the
likelihood that mirrors become misaligned. Com-
ments to the ANPRM explained that such mis-
alignment reduces a driver's ability to see chil-
dren in potentially dangerous locations around a
stopped school bus.

The NPRM asked the following questions
about mirror stability:

( 1 ) Could the requirements be made more
precise?;

(2) Is it necessary to require adjustable
mounting brackets for all types of cross view
mirrors?; and

(3) Do non-adjustable brackets reduce the
amount of vibration of the mirror while driving
or idling?

Commenters disagreed about the need for
requiring mirrors to have stable supports. NSTA
and Thomas Built believed such requirements
were not needed, with Thomas Built stating that
most current mirror mounting systems provide a

PART571;SlIl-PRE-39

stable yet easily adjustable mirror system. In con-
trast, Washington State and Transport Canada
supported the proposal to require stable supports.
Transport Canada favored an objective test to
evaluate the stability of mirror brackets for cross
view mirrors but had no particular recommenda-
tions to increase the requirement's precision.
Washington State supported the proposed regu-
latory language, agreeing that vibration can
significantly hami image quality. Nevertheless,
Washington State suggested that additional lan-
guage be included stating that if a minor adjust-
ment mechanism is necessary, it should be
designed so that vibrations would not misalign the
mirror. Arizona explained that its draft State mir-
ror requirements would specify that cross view
mirrors "shall be easily adjustable but be rigidly
braced to reduce vibration."

Commenters discussed the types of mirror
adjustment mechanisms cunently being used.
Some minor systems have both adjustable brack-
ets and mirrors, some only have adjustable mirror
portions, and others only have adjustable brackets.
Mirror Lite, Flynn, and Sloan believed that mir-
rors should be adjustable. Tennessee, Arizona,
and Blue Bird believed that mirrors should have
adjustable brackets. Blue Bird commented that
properly tightened adjustable brackets become
rigid and thus perfonn the same function as non-
adjustable brackets.

After considering the commenters' varying
views, NHTSA has determined that Standard No.
Ill's existing requirements for mirror stability
are appropriate, and they are adopted in this rule.
The agency recognizes that different mirror manu-
facturers have developed various types of mount-
ing brackets and miiTor mountings that employ
different degrees of adjustability or non-
adjustability. There is no evidence in the com-
ments to the docket, or in any of the mirror
evaluations the agency has conducted, that the
proposed requirements could be made any more
precise. NHTSA notes that Standard No. 1 1 1 cur-
rently requires '"stable support" for both inside
and outside mirrors on all types of vehicles, not
just school buses. The agency believes that these
requirements should be retained for school buses.
While a more precise requirement is not possible,
the agency believes it is important to retain a
requirement for minor stability in the standard as
a means of highlighting the importance of mirror
stability to mirror performance.

One change from the proposal is prompted by
Transport Canada's comment that the stability
requirements should also apply to the System A ■
minors. As Transport Canada stated. Standard
No. Ill's existing requirements for school bus
outside rearview mirrors include "stable sup-
ports." The agency agrees that the stability
requirements should continue to apply to System
A mirrors, and the final rule's requirements have
been modified accordingly.

Additionally, NHTSA notes that on April 26.
1991, it revised Guideline #17 to state "that all
school buses shall have a system of mirrors that
conforms to the school bus requirements of
FMVSS No. 111." (56 FR 19270) While this
amendment means that the most current require-
ments in Standard No. Ill are applicable, the
agency has decided to issue elsewhere in today's
Federal Register a conforming amendment to clar-
ify this situation. In particular, the conforming
amendment deletes the outdated requirements
referring to the 30 inch rod test in Guideline #17.

e. Informational label on using cross view mir-
rors for driving purposes. The NPRM discussed
the agency's concern about using convex cross
view mirtors as driving mirrors. These concerns ^
were based on the agency's belief that the inher- \
ently poor image clarity and image size reduction
characteristics of highly convex mirrors make
such mirrors inappropriate for driving purposes.
In addition, the reaction time is slower for drivers
using several mirtor systems each with signifi-
cantly different radii of curvature. Such mirrors
may not provide the driver with a consistent ref-
erence point with respect to the location of
images in the various mirrors. Accordingly, the
NPRM proposed that mirrors with an average
radius of curvature less than 35 inches be marked
with the following message:
"THIS MIRROR IS NOT DESIGNED FOR USE
WHILE THE VEHICLE IS IN MOTION."

The NPRM identified three issues about these
informational requirements: ( 1 ) The need for such
a message; (2) the message's content; and (3) the
message's location. As to location, the agency
proposed that the message be placed directly on
the minor, but requested comments about other
possible locations.

Regarding the need for an informational mes- f
sage on convex cross view mirrors, only NSTA V
and Thomas Built Buses believed that a message

PART 571: Slll-PRE-^0

was unnecessary. NSTA stated that the message
could impair the mirror's effectiveness and dis-
tract the driver. NSTA and Thomas Built said that
the message was unnecessary because they
believed that driver training would be more effec-
tive than a label whose benefits were question-
able.

All other commenters supported having an
informational label either expressly (Mirror Lite,
R&R Research, Washington State, and Sloan
Company) or implicitly (Transport Canada, Anne
Arundel County Schools, New York State. Ten-
nessee DOE, Arizona DOT, Lo-Mar, and Blue
Bird) by not objecting to the label, while com-
menting on the location, size, or wording of the
warning. R&R Research stated that an informa-
tional label was necessary because in practice
drivers use cross view mirror systems to gain
information on traffic conditions around the bus.

After considering the comments, NHTSA has
determined that a message explaining the proper
use of convex cross view mirrors is necessary
since some drivers use these mirrors for driving
purposes. The agency is aware that properly
trained drivers will have been taught that these
mirrors are for pedestrian detection purposes only.
Accordingly, NHTSA believes that the label will
serve more as a reminder message rather than as
an "instructional" message for those drivers
trained in the proper operation of school buses
and use of mirror systems. The agency believes
that the message will also benefit untrained driv-
ers, by informing them about the mirror system's
proper use.

As to the content of the message, R&R
Research commented that the label should
communicate two things: the correct action
required of drivers, and the potential con-
sequences of inappropriate behavior. NHTSA
agrees with R&R's comment that a more positive,
informative message would provide greater poten-
tial safety benefits than the proposed one. Specifi-
cally, the message adopted in the final rule
explains what action should be taken (i.e., use the
mirror to detect pedestrians), what action should
not be taken (i.e., do not use the mirror to view
traffic), and why the mirror should not be used
inappropriately (i.e., the images do not accurately
show another vehicle's location). Accordingly, the
message required by the final rule has been
changed to read as follows:

"USE CROSS VIEW MIRRORS TO VIEW
PEDESTRIANS WHILE BUS IS STOPPED. DO
NOT USE THESE MIRRORS TO VIEW TRAF-
FIC WHILE BUS IS MOVING. IMAGES IN
SUCH MIRRORS DO NOT ACCURATELY
SHOW ANOTHER VEHICLE'S LOCATION."

Many commenters addressed the proper loca-
tion for an informational message about cross
view mirrors. Only Anne Arundel County favored
placing the message on the mirror itself, claiming
that placing this message elsewhere inside or out-
side the bus would create problems since many
buses already are required to contain several mes-
sages.

All other commenters, including R&R
Research, New York State, Lo-Mar, Arizona
DOT, Tennessee DOE, Transport Canada,
Washington State, and Mirror Lite, recommended
that the message be placed inside the school bus
near the driver instead of on the cross view mir-
ror itself. Commenters stated that a message
placed directly on the mirror would be difficult to
read and would obstruct some images, thus
adversely affecting mirror performance. Tennessee
DOE stated that the message should be placed on
or near the instrument panel. New York State
favored including the message on a sticker
attached to the bus in the line of sight of the
driver when observing the mirror. R&R Research
favored placing the message inside the bus either
on the instrument panel or near the interior rear
view mirror.

After considering the above comments, NHTAS
has decided that the message should be located
inside the school bus near the bus driver instead
of on the convex cross view mirror. The agency
agrees with the comments that a message placed
directly on the mirror would be difficult to see
and would reduce mirror performance by obscur-
ing some mirror images. As noted above, the
agency's primary goal is for drivers to understand
that these mirrors should not be used while the
vehicle is in motion because information obtained
in such situations is not accurate enough to make
appropriate driving decisions.

The agency agrees with Anne Arundel County
that the driver's area already contains a number
of informational labels explaining proper school
bus operations. Since the agency is unaware of
any single "best" location for the mirror-use
label, the final rule provides flexibility to bus
manufacturers in placing the label at an appro-

PART57I; Slll-PRE^l

priate location which is prominent and visible
within the driver's area of the bus. The standard
requires the label to be printed in type face and
color that are clear and conspicuous. NHTSA
notes that these locations, size, and color require-
ments are patterned after the warning label
requirements for utility vehicles in 49 CFR
575.105.

f. Peiformance requirements for image clarity.
The NPRM proposed performance requirements
to ensure that the images in cross view mirrors
were of sufficient minimum quality to provide the
school bus driver with reliable infomiation about
the presence of children in front of and along
both sides of the bus. In selecting these proposed
requirements, the agency relied on the VRTC
report's finding that only a limited level of image
quality is necessary to ensure that a school bus
driver is aware of a student in a dangerous zone,
so as not to move the bus until the student has
moved to a safe location.

The NPRM proposed two requirements to
ensure adequate image quality. First, the separa-
tion between the edge of each cylinder's image
and the edge of the effective mirror surface would
have to be not less than 3.0 minutes of arc. This
requirement stems from the agency's finding that
the most difficult images to recognize are elon-
gated ones near the mirror's curved reflective
edge. Second, with respect to the image of the
cylinder perpendicular to and twelve feet away
from the rear right axle, the angular size of the
longest dimension of that image would have to be
not less than nine minutes of arc and the angular
size of its shortest dimension would have to be
not less than three minutes of arc. This require-
ment stems from the agency's finding that
unreasonable elongation would make it difficult
for the driver to identify a child's image in the
mirror.

Several commenters addressed the issue of
image quality. Mirror Lite believed that a test
procedure was necessary to reduce distortion due
to a flawed mirror surface and to increase image
quality. NSTA stated that only a reasonable level
of image quality is necessary, since a driver needs
only to recognize that an object in the mirror is
a child and does not need to know specific details
about the image. Thomas Built commented that
the specification for the minimum distance
between the image and the mirror's effective edge
could be eliminated, believing that the elongation

requirements of S9.4(b) (1) and (2) should make
the image "acceptable."

Commenters also provided general comments #
about the image quality requirements. Transport ^
Canada stated that when a cylinder is visible in
two mirrors, both images should have to meet the
requirements for minimum size and distance from
the mirror's edge, believing that this would ensure
that a small child would not be overlooked. While
Blue Bird agreed that the location of the image
relative to the outer edge of the mirror surface
should be limited, it believed that the proposed
requirement of three minutes of arc would be dif-
ficult to measure given its dependence on the fol-
lowing variables: (1) The radius of effective mir-
ror surface, (2) mirror adjustment by the driver,
and (3) distance from the driver's eye location to
the image in the mirror for different mirror com-
binations and bus types on which mirrors are
mounted. Blue Bird was concerned that this pro-
posal would result in ambiguities given potential
problems in accurately measuring the allowed
mirror distance between the image and edge of
the mirror. Blue Bird recommended establishing a
limit on the distance between images and the mir-
ror edge which it characterized as being more ^
easily measurable during compliance testing. \

Several commenters provided specific sugges-
tions about changing the requirements for image
quality. Thomas Built recommended that each
cylinder's top surface have a letter which would
be used to evaluate image clarity. Thomas Built
believed that the proposed three minutes of arc
was "minute and undeterminate," stating that on
a mirror with a 28 inch radius of curvature, three
minutes of arc is only .024 inches. Accordingly,
Thomas Built suggested the requirement be elimi-
nated unless a fixed dimension such as '/4 inch is
specified. Similarly, Blue Bird suggested
establishing a fixed distance of '/i6 inch along the
effective mirror surface's edge to be blocked out
during compliance testing.

After reviewing the comments, NHTSA
repeated several mirror evaluations and created
charts representing a distance of three and nine
minutes of arc for use in the proposed test proce-
dure. (See Figure 4.) Based on that evaluation's
results, the agency believes that three minutes of
arc can be accurately measured and that this /
dimension provides adequate separation between \^
the test cylinders and the effective edge of the

PART 571; Slll-PRE-42

mirror. Accordingly, the final rule adopts the pro-
posed three minutes of arc requirement.
^ As for Thomas Built's suggestion to letter the

^^ tops of the cylinders, NHTSA notes that the
VRTC report found that such precision is not nec-
essary for the driver to recognize that a pedestrian
is in danger. In addition, such a high level of
precision might be impracticable for certain mir-
rors that nonetheless provide an adequate field-of-
view. Similarly, the agency believes that adopting
Transport Canada's recommendation for multiple
images of the same cylinder to comply with the
image clarity requirements would be unnecessary
for safety and would be redundant. Moreover,
such a requirement appears to be impracticable
based on the agency's evaluation of various mir-
ror systems.

As for the suggestions by Thomas Built and
Blue Bird to establish a minimum fixed dimen-
sion of either Vie or V4 inch between the test cyl-
inder image and the mirror's effective edge,
NHTSA believes such an approach would be nei-
ther practicable nor appropriate. NHTSA notes
that the "effective edge" of a convex mirror var-
ies depending on the adjustment of the mirror and
the driver's eye location. Accordingly, it is not
^ feasible to specify a measurement from a variable
location since the effective edge of a convex
cross view mirror is often toward the center of
the mirror, instead of at the actual edge of the
mirror.

g. Image elongation. As noted above, the
NPRM proposed language controlling the mini-
mum angular size of the image of the test cyl-
inder located twelve feet perpendicular to the side
of the bus at the right rear axle line. The purpose
of this proposal was to ensure that the image
would not appear unreasonably elongated, a
phenomenon that might prevent drivers from
being able to identify a child's image in the mir-
ror. As noted in the VRTC report and in the
agency's in-house evaluation, drivers have the
most difficulty seeing images of objects along the
axis perpendicular to the right rear wheel because
some current designs of convex cross view mir-
rors unreasonably elongate the image.

Several commenters expressed their views
about the elongation requirement. R&R Research
stated that the proposed minimum image sizes of
^ three minutes and nine minutes of arc would be
w adequate as a minimum standard for most situa-
tions. Nevertheless, it believed that occasionally a

driver with poor vision in low contrast situations
would not be able to detect objects in a mirror
designed to comply with the proposed minimum
image size requirements.

Blue Bird objected to the proposed elongation
requirements, claiming not to understand the use
of cylinder N to measure distortion. Blue Bird
believed that the agency did not justify the speci-
fied angular dimensions for a distorted image
viewed in any particular mirror, arguing that the
proposed angular sizes may be too restrictive and
may not correspond to real-world situations. In
support of its argument. Blue Bird cited the
VRTC report which stated that "It is better to
have a 'distorted' object in the mirror than no
object at all." Based on the above. Blue Bird
requested that the agency conduct additional
research to determine practical real-world limits
for allowable image distortion.

Commenters also offered specific recommenda-
tions about the performance requirements for
elongation. R&R Research suggested that the final
rule contain either a table of target dimensions
that subtend the three and nine minute visual
angles when viewed at a specified distance or
contain the mathematical formulae to calculate
them. Lo-Mar requested that "angular size" be
better defined, claiming that the angular size of
the cylinder's image in the mirror is confusing.
Nevertheless, Lo-Mar offered no specific sugges-
tions.

Transport Canada suggested that the image size
requirements be extended to all cylinders in all
mirrors, stating that cylinder N will not nec-
essarily appear in the mirror at the mirror's
smallest radius of curvamre. Transport Canada
also suggested that the minimum angular size for
cylinders A through F be five minutes of arc, and
the minimum angular size for cylinders G through
K be ten minutes of arc.

After reviewing the comments and conducting
additional mirror evaluations, NHTSA has
decided to adopt the proposed requirements for
minimum angular dimensions of test cylinder N
in this final rule. The agency notes that the test
cylinder identified as N in the NPRM is identified
as cylinder P in this final rule. The agency
believes that the elongation requirements are nec-
essary to protect against poor image quality for
objects toward the rear of the bus.

In response to the comments from Transport
Canada, Lo-Mar, and Blue Bird, the agency notes

PART 571; Slll-PRE-43

that test cylinder P will most often be located fur-
ther toward the edge of the effective mirror sur-
face than the other test cylinders. Therefore, cyl-
inder P's image will typically be a worst-case
image that is subjected to more spherical aberra-
tion than other images that are further from the
effective edge of the mirror. Because of this, the
image of cylinder P will typically be the least
clear. This fact, combined with test cylinder P
being located the farthest away from the mirror
and driver, indicates that controlling the image
clarity of test cylinder P should effectively control
the image clarity of all test cylinders.

NHTSA believes that the minimum angular
sizes (three minutes and nine minutes) adopted
here in the elongation requirements are consistent
with the dimensions adopted in the image clarity
requirements for the distance from test cylinders
to the effective edge of the mirror (three minutes).
Both sets of dimensions were based on NHTSA
mirror evaluations and the capabilities of these
existing mirrors to meet those dimensional limits.
While real-world evidence to define conclusively
the optimum image sizes is not available, and
may be impossible to obtain because of the many
factors influencing the clarity of an image in a
cross view mirror, the agency believes the
adopted image clarity and elongation requirements
are reasonable and practicable. Aside from the
objections by Blue Bird and Lo-Mar, no other
comments were received on this subject. The
agency assumes that the other commenters tacitly
approved the image clarity and elongation
requirements since the NPRM expressly asked
about the reasonableness and practicability of
these requirements, a subject about which the
commenters are generally knowledgeable.

After reviewing R&R Research's comment
about including a comparison chart and the
mathematical formula, the agency has decided to
modify the final rule to incorporate a size chart
for three minutes and nine minutes of arc and the
formulae for calculating them.

E. Testing procedures

1. General

Based on the VRTC report and other agency
findings, the agency proposed in section S13 cer-
tain test procedures under which the proposed
perfomiance requirements would be evaluated. As
explained below, the NPRM proposed detailed

specifications about the characteristics of test cyl-
inders and their placement at critical locations in
front of and along both sides of the school bus. ^
The NPRM also proposed a testing reference ^
point and testing procedures, including the
photographing of test cylinders.

2. Testing Reference Point 25th Percentile Female

The NPRM proposed that compliance testing
be measured relative to the center point of the eye
location of a 25th percentile adult female rep-
resented by a two dimensional manikin. The
agency selected this sized driver because such a
driver tends to have a poorer direct field-of-view
of the area near the bus than a taller (e.g., 95th
male percentile) driver.

The proposed regulatory text in SI 3.2 con-
tained specific information on determining the eye
location of a 25th percentile adult female seated
in the driver's seat. These provisions concerned
the seat's position and adjustment procedures.

Several commenters addressed the testing
requirements related to the driver position. R&R
Research believed that the standard need not refer
to the 25th percentile female since precise dimen-
sions from the seat are provided. Blue Bird dis- ^
agreed with the use of a 25th percentile female fl
for identifying the eye location, stating that for ^
passenger cars. Standard No. HI uses a driver's
eye location corresponding to a 95th percentile
male. Notwithstanding its criticisms. Blue Bird
acknowledged that the proposed eye location
procedures would allow precise determination of
the driver's eye location in any bus. Transport
Canada believed that multiple eye locations
should be used in the test procedure, including a
5th percentile female and a 95th percentile male.
It stated that the 95th percentile male provides the
worst-case viewing in indirect field-of-view situa-
tions since that type of driver sits farthest from
the mirrors.

After reviewing the comments, the agency
continues to believe that the eye location of the
25th percentile adult female is appropriate for
representing a "worst case" for visibility. There-
fore, the proposed requirements are adopted in
this final rule. The agency notes that because the
adopted requirements consider the bus's entire
field-of-view and not just the indirect view cre-
ated by miiTors, the 25th percentile female pro- A
vides a more stringent testing perspective than a ^
95th percentile male. This consideration out-

PART 571; S11I-PRE^4

weighs the perceive benefits from having consist-
ent reference points in Standard No. Ill for all
I the different types of vehicles.

The agency believes that Transport Canada's
suggestion that eye locations be based on 95th
percentile males and 5th percentile females would
create excessive requirements. As discussed below
in the section on "Camera Testing Points." the
final rule allows for compliance within an area
formed by the points of an arc located six inches
to the left, forward, and right of the eye location
of a 25th percentile adult female. Such a require-
ment recognizes that drivers typically move their
heads while viewing mirrors, and that the range
of these movements would encompass eye loca-
tions for various size drivers.

As R&R Research stated, the final rule pro-
vides dimensional information for locating the
center point of the driver's eye location. Even
though it may not be strictly necessary to do so,
the agency believes that the rule should expressly
state that the source of that dimensional informa-
tion is the 25th percentile adult female.

3. Mirror Adjustment During Testing

The NPRM proposed that the mirrors be
I adjusted in accordance with the manufacturer's
recommendations (see S13.3). Several com-
menters addressed the issue of mirror adjustment.
R&R Researcher and Transport Canada stated that
the agency should modify proposed SI 3.3 in the
final rule to state that, once adjusted, the mirrors
must remain fixed in one position throughout the
measurement procedure. On the other hand. New
York State commented that mirrors subject to
Standard No. Ill should be remotely adjustable
from the driver's seat to accommodate the eye
locations of different size drivers.

After reviewing the comments, NHTSA has
decided to modify the language in SI 3.3 to pro-
hibit moving or adjusting mirrors during compli-
ance testing. The agency's intention in the NPRM
was to require mirrors that would, once properly
adjusted, afford the driver a clear view of children
present around stopped school buses. Mirrors that
must be repeatedly adjusted to view the entire
area around the stopped bus would not effectuate
that intention. In addition, mirrors that must be
repeatedly adjusted are not likely to be adjusted
I every time by the driver, which would mean there
' potentially could still be situations where the
driver could not detect child pedestrians around

the stopped school bus. To ensure that the mirrors
required by this final rule will not need any fur-
ther adjustments after the initial one. this rule
modifies the proposed language in SI 3.3 to make
such a requirement explicit.

This rule has not been modified in response to
New York's comment about remotely adjustable
mirrors. As explained above, the agency is seek-
ing to require mirrors that will offer a clear view
of the area around a stopped school bus without
any further adjustments after the initial one.
While remotely adjustable mirrors are now avail-
able, they will not be considered as complying
with this rule if they must use their adjustability
characteristics to provide the required view during
testing.

4. Camera Testing Points

The NPRM proposed that observations would
be made and photographs taken of the test cyl-
inders from a point representing the center of the
driver's eye location for a 25th percentile adult
female, as well as at locations six inches forward,
left, and right of the center of the driver's eye
location. These multiple positions were intended
to account for head movements. Under the pro-
posed test procedures, cylinders that were directly
viewable would be evaluated first, and then cyl-
inders that were not directly viewable would be
evaluated. In both situations, the evaluator would
look through a camera's film plane to determine
whether the entire top surface of a test cylinder
could be directly seen. A comparison chart placed
above each mirror would serve as a reference
point in evaluating the image size and amount of
distortion of cylinders visible in a mirror.

Many commenters addressed the requirements
related to the camera locations. The Arizona DOT
supported the proposed procedure. According to
this commenter, it evaluated some existing mirror
systems in accordance with the proposal and
determined that the driver's eye location can be
established and the camera location is correct.

Other commenters either criticized the proposed
camera-related testing procedures or offered
suggestions to improve the requirements. Mirror
Lite was concerned that the camera location
requirements would be interpreted differently by
various bus manufacturers, but did not explain the
basis for its concern. Thomas Built requested that
mirror systems should only have to meet the test
requirements from any one of the allowable cam-

PART 571; Slll-PRE-45

era locations instead of all locations, claiming that
the time and cost of conducting photographic tests
at multiple locations would be unreasonable. In
support of its request, Thomas Built stated that
the proposed requirement would require it to
evaluate 140 bus/driver seat combinations for any
given mirror system since certification testing
would have to be conducted on each type of bus
with each type of driver seat offered. Since
Thomas Built estimated that evaluating one seat
in one bus with one mirror system required about
80 man hours and $ 1 25 of photographic materials,
it viewed the testing necessary to evaluate 140
combinations as being overly burdensome.

Blue Bird criticized using a camera to measure
compliance, citing such concerns as the camera's
monocular vision, the burden to customers of
many photographs and their duplication for docu-
mentation purposes, the camera's inability to
define correctly the direct field of view, and its
inability to consider adjustments made by humans
in mirror visibility.

Transport Canada requested that video cameras
be allowed, claiming that their use would permit
viewing of images superior to those seen by cam-
eras. It also requested that the requirements pro-
vide more detail on the focal length of the camera
lens.

After reviewing the comments, NHTSA agrees
with Thomas Built that requiring testing at mul-
tiple points would be overly burdensome and
would not yield significantly more worthwhile
information. Upon reexamination, the agency now
believes that a more appropriate procedure would
be to allow testing to be done at any point within
a specified area around the 25th percentile adult
female driver's eye location. Such a procedure
more accurately accounts for real-world situations
in which drivers typically move their heads while
they view mirror systems. Based on the above,
the agency is changing SI 3.4 in this final rule to
allow compliance with the standard at any one of
the four points specified in Figure 3 (point "A,"
"B," "C," or "D") or at any single point within
a semicircular area established by a 15.24 centi-
meter (6 inch) radius parallel to and forward of
the center point. This viewing zone is illustrated
in Figure 3. The agency anticipates that this
modification will provide meaningful infomiation
about the driver's view of critical areas around
the bus, while reducing the photographic time and

cost factors mentioned by Thomas Built by 75
percent. The agency believes that if a vehicle
manufacturer can establish compliance at one of
the four testing points or any point in the semi-
circle, then that mirror system on that school bus
should provide an adequate field-of view given
the small size of the semicircle.

NHTSA believes that Blue Bird's concerns
about a camera's monocular vision and its inabil-
ity to define the direct field of view are philo-
sophical in nature and relate to the inherent
limitations of current technology. Given the avail-
able means to demonstrate objectively compliance
with this standard, NHTSA is unaware of any
other means that would be as effective, as prac-
ticable, and as easy to demonstrate as the use of
a camera.

As for Mirror Lite's claim that the camera
location specifications were ambiguous, the
agency disagrees. NHTSA believes that difficul-
ties in interpretation are unlikely, because the
camera location specifications are well defined
and easily achieved in actual testing situations.

As for Transport Canada's comment about
video cameras, NHTSA has determined that this
testing method is appropriate and should be per-
mitted. Accordingly, the final rule at SI 3.4 has
been modified. While video technology as a
means for demonstrating compliance with this
standard may currently be less practicable than
still photography, the agency believes that techno-
logical improvements may make video cameras a
more viable option in the fuhare. The agency
therefore has decided not to preclude their use. To
accommodate this modification, the term "film
plane" has been changed to "image plane."

As for a lens focal length, the agency does not
believe specifications about the focal length of
lens are necessary. During the agency's mirror
evaluations, lenses of various focal lengths were
used to photograph the mirror images, including
50 mm to 250 mm lenses. While the ability to
analyze the results was acceptable with all lenses,
the agency noted that less enlargement was nec-
essary when using a lens with a longer focal
length. The agency believes it is reasonable to
allow the entity conducting the test to select the
type of camera and lens best suited to its pur-
poses.

PART 571; S111-PRE^6

F. Miscellaneous Considerations

1 . Certification

" Thomas Built requested that the mirror manu-

facturer be responsible for certifying the image's
quality and the bus manufacturer be responsible
for certifying the field-of-view. It stated that this
division of responsibility would simplify the test-
ing and development process between mirror and
bus manufacturer.

NHTSA notes that Thomas Built's suggested
certification scheme would be inconsistent with
the scheme set forth in Standard No. 111. That
standard is a "vehicle"" standard under which the
vehicle manufacturer, and not the mirror manufac-
turer, is responsible for ensuring that a mirror
complies with the standard. This ensures that
vehicles equipped with noncomplying mirrors will
be quickly remedied, without the need for a spe-
cific determination of whether the noncompliance
arose because of an innate problem with the mir-
ror or because of its installation on these particu-
lar vehicles. The agency does not believe there is
any reason to change this scheme for school
buses under Standard No. 111. Notwithstanding
this conclusion, the agency notes that a vehicle

i manufacturer can establish in its purchase speci-
fications whatever level of requirements it
chooses for its suppliers and take appropriate
actions if the supplier"s products fail to conform
to those specifications.

2. Retrofitting

Several commenters, including the National
PTA and the National Education Association
(NEA), advocated that NHTSA require existing
school buses to be retrofitted to comply with the
new requirements. The National PTA stated that
the agency's decision not to retrofit existing
school buses was "based more on a lack of regu-
latory courage than legal restrictions."

The agency's statutory authority under the
National Traffic and Motor Vehicle Safety Act
(the Safety Act; 15 U.S.C. 1381 et seq.) is to
issue safety standards applicable to new motor
vehicles and new items of motor vehicle equip-
ment before their first consumer purchase. The
Safety Act expressly provides that vehicles and
items of equipment are not required to continue
to comply with all applicable safety standards
' after their first purchase for purposes other than
resale. See section 108(b)(1) of the Safety Act (15

U.S.C. 1397(b)(1)). Thus, NHTSA's safety stand-
ards regulate the manufacture and sale of new
vehicles and items of motor vehicle equipment.
Regardless of the agency's "regulatory courage,"
amendments to the safety standards do not and
cannot require vehicles in service to comply with
the requirements adopted in final rules.

However, the individual States do have the
authority to regulate vehicles in service. Notwith-
standing the lack of Federal authority to order
school buses already in service to meet these
amended requirements, the agency anticipates that
many in-use school buses already comply with or
will be retrofitted by State and local authorities to
comply with these amended requirements.

3. Applying Requirements to Buses Other Than
School Buses

New York State recommended the agency
apply the new field-of-view requirements to all
transit-type vehicles that transport the public.

NHTSA notes that New York's recommenda-
tion to apply the field-of-view requirements to
non-school buses is beyond the scope of this rule-
making action, since the NPRM only proposed
new requirements for school buses. The agency
notes that the benefits of applying these require-
ments to transit buses appear questionable since
most school bus-related incidents involve children
under the age of seven. Notwithstanding the
above discussion, the agency does not prohibit
using "school bus'" mirror systems on other types
of buses.

4. Heated Mirrors

New York State and Moto Mirror requested
that the agency require school buses to be
equipped with heated mirrors, at least for those
areas that experience cold weather.

NHTSA recognizes that some northern portions
of the country experience weather conditions
where mirror systems can become covered with
ice and snow. While these conditions affect the
potential effectiveness of the mirror systems,
NHTSA believes that the responsibility for
maintaining the mirror systems, and any part of
the vehicle which affects the performance of the
mirror systems, is best left with the State and
local school districts. The agency further notes
that since school buses are manufactured for use
in all parts of the country, they must comply with
all applicable standards. Therefore, it would be

PART 571; Slll-PRE-47

unreasonable to promulgate a national standard
that would have little or no benefit for a signifi-
cant part of the country.

5. Maximum Permissible Number of Mirrors

Several commenters addressed the number of
mirrors with which a school bus should be
equipped. R & R Research believed that the new
standard should address the number of mirrors
allowed on a school bus and the size of the mir-
rors. While the number of mirrors affect the time
a driver needs to search visually the area around
the bus, mirror size affects the blind spots created
by the mirrors themselves. Transport Canada
believed that the number of rear-view mirrors
should be limited to one per side to avoid pos-
sible confusion produced by multiple images and
reduce the total time drivers must divert their
attention from the road ahead.

While NHTSA is aware of the situation men-
tioned by R & R Research and Transport Canada,
no provision limiting the number of mirrors on
school buses has been included in this final rule
because the agency does not believe that there
would be a safety benefit from such a limitation.
The agency further notes that a major purpose for
this rulemaking's field-of-view approach is to
allow school bus users and manufacturers to
determine the best mirror system for their particu-
lar operating environment.

6. Blind Spots

The NPRM requested comments about whether
the mirrors would create dangerous blind spots in
the driver's direct field-of-view, given the size
and location of some convex cross view mirrors.

Several commenters believed that the agency
should address the potential problems of blind
spots created by miiTors. R & R Research
believed that any new standard should address the
mirror size, since this affects the blind spots cre-
ated by the mirrors themselves. Transport Canada
suggested that mirrors be located in areas that do
not obstruct the driver's direct view of traffic and
pedestrians. Thomas Built and a bus driver com-
mented that while convex cross view miiTors do
not create significant blind spots, side mounted
driving mirrors may decrease visibility.

Other commenters believed that blind spots
were not a significant safety problem. Arizona
DOT stated that the increased field-of-view pro-
vided by mirrors offsets the corresponding blind

spots. Blue Bird stated that blind spots created by
a cross view mirror on one side of the bus can
be viewed in the cross view mirror system on the ^M
other side of the bus. ^*

NHTSA agrees with Arizona DOT that blind
spots in the direct field-of-view created by mir-
rors themselves are offset by the larger indirect
field-of-view provided by the mirror system.
Although NHTSA does not believe it is appro-
priate to establish requirements for mirror loca-
tions, the agency does believe that mirror and
school bus manufacturers should strive to develop
mirror locations which limit the amount of
obstruction to the driver's direct field of view.

7. Glare from Mirrors

The NPRM asked whether glare from some
cross view mirror designs, caused by turn signals
and other school bus lights, would reflect light
from flashing turn signals into the driver's eye.

Of those who commented on this issue
(Thomas Built. Blue Bird. Arizona, Mirror Lite,
Tennessee), no commenter believed that glare
caused a significant safety problem. Based on the
comments, the agency does not believe that
reflected light or glare from convex mirrors pre- ^
sents an unreasonable safety risk to school bus ^
drivers.

8. Non-Mirror Systems

The NPRM discussed the docket comments
received about mechanical and electronic devices
which could be used either to keep students away
from critical areas around the school bus or to
alert school bus drivers to the presence of some-
one in a critical area around the bus. The agency
explained that mirrors offer the most effective
means of providing the school bus driver with a
complete view in front of and along both sides of
the bus. The agency believed that requiring these
additional non-mirror devices "would substan-
tially increase compliance costs without signifi-
cantly increasing safety benefits."

The Arizona DOT agreed that instead of requir-
ing such devices, it would be more cost effective
to evaluate their effectiveness through pilot pro-
grams. SCAN, the manufacturer of an electronic
detection system, requested that the agency mod-
ify the field-of-view requirements to allow
compliance through mirrors or sensing/detection M
devices. SCAN believed that the NPRM was "
unduly negative toward its type of product and

PART 571; S111-PRE^8

requested that critical comments from Blue Bird
and Thomas Built about non-mirror systems be
stricken from the docket.

The agency continues to believe that, in terms
of performance, reliability, and cost, mirrors offer
the best means for school bus drivers to become
aware of pedestrians in front of and along both
sides of the bus. Accordingly, the agency does
not agree with the SCAN's belief that sensing/
detection devices should be allowed as a means
of meeting the standard's field-of-view require-
ments. Notwithstanding this decision, sensing/
detection devices may be used as supplementary
devices on school buses.

G. Costs

In previous notices, NHTSA considered the
rulemaking's expected cost. The ANPRM esti-
mated that the unit cost for a System B convex
cross view mirror with a bracket plus installation
would range from $52 to $107. The NPRM
explained that the costs of an additional convex
cross view mirror would range from $58 for a
four 8" (17" ROC) convex mirror system to $121
for an 8"xl2" quadrispheric "Bus Boy" mirror
system. The proposal noted that, since school bus
manufacturers and users were free to choose what
convex cross view mirror system they would use
to comply with the performance requirements,
those parties' choices would greatly affect the
ultimate costs. However, the agency anticipated
that the cost of complying with the proposed
changes would be minimal because of the current
State mirror specifications. For example. States
that currently specify four 8" (17" ROC) convex
mirrors on cross view tripods, at a cost of $58.00,
could switch to a pair of elliptical mirrors which
cost nearly the same — $58.10.

The NPRM requested comments about this
proposal's cost to school bus users and informa-
tion about current State requirements for school
bus mirrors.

Several commenters, including States and
school bus manufacmrers, generally agreed with
the NPRM's cost estimates. The Arizona DOT
and Tennessee DOE commented that the NPRM's
cost estimates were accurate. Mirror Lite com-
mented that the parts cost (i.e., mirrors and
mounting arms) of four currently used standard 8"
mirrors on a conventional bus is $44; while, the
cost of two Bus Boy mirrors and brackets would
be $5 1 , a $7 difference. While Mirror Lite did not

provide a cost for installation, the agency believes
that the installation cost for two Bus Boy mirrors
would be approximately the same as four 8" con-
vex mirrors, if two such mirrors are mounted on
the same bracket.

A few commenters believed the rulemaking
would result in significant additional costs. Moto
Mirror, a mirror manufacturer, stated that the
aftermarket cost of a dual set of motorized and
heated mirrors would be $362.05. The agency
notes that these mirrors include motorized and
heated features that the standard does not require.
Blue Bird commented that available mirror sys-
tems that will meet the proposals have an addi-
tional cost of approximately $115.00 per bus
above the cost of the standard mirror system it
currently uses. R&R Research believed that the
cost of installation and adjustment may exceed
the cost of the hardware for some mirror systems,
but provided no details to support the statement.

After reviewing the available information,
NHTSA believes that the NPRM's initial cost
estimates are generally reasonable. With respect
to System A costs, the agency notes that all buses
are typically equipped with supplemental convex
driving mirrors as part of their System A mirrors.
Thus, no real change in these mirrors would be
necessary for school bus users to meet System A
requirements. As for R&R Research's concern
about installation, the agency has discussed mirror
installation with bus manufacturers and State and
local school district officials at various school
transportation trade shows and has not found any
supporting information for R&R's claim.

As to Blue Bird's comment on the $115 dif-
ference in the cost for a compliant mirror system,
they were referring to a quadrispheric mirror sys-
tem. They also inadvertently included the cost of
the right and left side flat, rearview mirrors as
part of the cost increase; this was not appropriate.
Blue Bird resubmitted a cost increase of $30 per
bus, to the consumer, when equipped with a
quadrispheric mirror system rather than the stand-
ard four 8" convex cross view mirror system.
They further stated that as such mirror systems
gain popularity among the users, that cost will
drop.

With regard to Thomas Built's estimate of 80
man hours needed to complete a compliance test
of a single bus-seat-mirror combination, it has
been the agency's experience, through VRTC,
that about ten man hours are necessary to do this

PART 571; Slll-PRE-49

type of test. Included in the agency's time esti-
mate are such tasks as locating the cylinders
around the bus, adjusting the mirrors, mounting a
camera tripod in the driver's seat area, taking
slides, processing film, and analyzing slides. The
agency's estimate does not include one-time tasks
such as setting up a grid of one foot by one foot
squares and the constructing the test cylinders.
Although many bus-seat-mirror configurations
will need to be tested, once a particular configura-
tion has been certified to meet the standard, that
configuration will not need to be retested in sub-
sequent years. Therefore, such one-time test costs
would be distributed over the years that such a
configuration is in use. Also, the agency believes
that a limited number of design changes in bus
exteriors and/or drivers' seats occur from year to
year and any differences in the location of the
25th percentile adult female's eye location that do
occur would be small and should not greatly
affect the driver's direct or indirect field of view.
These eye location differences among seats
would, however, establish a compliance
"envelope" spanning the eye locations that allow
compliance with the standard. Thus, further
reductions in time and cost would occur by not
having to test any new configurations that would
have minute eye location differences between pre-
viously tested configurations. Finally, the agency
expects that further time savings will occur as
more and more tests are performed.

H. Leadtime Requirements

The NPRM explained that many mirror systems
are now available which would comply with the
proposed field-of-view requirements, and thus
would not create leadtime constraints from that
perspective. Nevertheless, the agency believed
that school bus manufacturers and users should be
afforded time to investigate and select how they
wish to comply with the new field-of-view
requirements. Accordingly, the agency proposed
an effective date of one year after publication of
the final rule.

Several commenters addressed the leadtime
necessary for this rulemaking. The NEA favored
having the final rule become effective as soon as
possible. The Arizona DOT stated that there cur-
rently are mirrors that could be used to comply
with the one year leadtime requirements. NSTA
requested a leadtime of 18 months after publica-
tion of the final rule for the effective date, claim-

ing that additional time was necessary to allow
school districts to budget for the additional costs
associated with the rulemaking. ^|

After reviewing the comments, the agency ^*
continues to believe that a one-year leadtime after
the final rule's publication provides adequate time
for school bus manufacturers and users to deter-
mine how to comply with the new field-of-view
requirements. The agency notes that most school
bus manufacturers are already familiar with all of
the brands of mirrors. The extra six months
requested by NSTA is not warranted on the basis
of other comments.

This final rule does not have any retroactive
effect. Under section 103(d) of the National Traf-
fic and Motor Vehicle Safety Act (15 U.S.C.
1392(d)), whenever a Federal motor vehicle safety
standard is in effect, a State may not adopt or
maintain a safety standard applicable to the same
aspect of performance which is not identical to
the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending or
revoking Federal motor vehicle safety standards.
That section does not require submission of a
petition for reconsideration or other administrative ^
proceedings before parties may file suit in court. ^

Rulemaking Analyses and Notices

Executive Order 12291 (Federal Regulation) and
DOT Regulatoi-y Policies and Procedures

NHTSA has considered the costs and other
impacts of this rulemaking, and a Final Regu-
latory Evaluation (FRE) has been prepared and
placed in the docket. Based on this evaluation, the
agency has determined that the rulemaking is not
■'major" within the meaning of Executive Order
12291. However, it is "significant" within the
meaning of the Department of Transportation's
regulatory policies and procedures.

As explained in the FRE, the additional cost of
installing a pair of compliant convex cross view
mirrors on a new school bus could range from no
cost to as much as $30 per school bus, depending
on the type of mirror system selected by the
school district. About 38,000 new school buses
are sold each year, and according to Blue Bird
about 12 percent of all their buses are equipped
with a compliant mirror system. Therefore, ^
assuming Blue Bird's sales breakdown is rep- ^
resentative of the overall bus manufacturing

PART 571; Slll-PRE-50

industry, about 33,440 buses (38,000 x 88 per-
cent) will have to be equipped with a compliant
) system. Therefore, the aggregate annual cost to
consumers would range from no cost to about
$1,003,200. (33,400 x $30 per bus).

NHTSA anticipates that the actual costs will
likely be nearer the lower end of the estimated
cost range for the following reasons. Buyers will
probably select lower cost mirrors since they are
quite sensitive to cost. At the same time, econo-
mies of scale and competition will lower the costs
of the more expensive mirrors. The agency further
notes that since nearly all States now require
school buses to have more mirrors than required
by FMVSS No. Ill, the costs of complying with
this rulemaking could even result in a cost sav-
ings for those school buses being sold in jurisdic-
tions where buses are currently equipped with
more expensive mirrors than a mirror system that
will now be allowed under the amendments.

As mentioned in this notice's "background"
section, an average of 26 students are fatally
injured and another 283 are injured when struck
by their own school bus. While the effectiveness
of upgrading the requirements for school bus mir-
i TOTS cannot be conclusively established, accounts
' in the NAS report and docket comments indicate
that some injuries and fatalities will be avoided.

Regiilatoiy Flexibility Act

NHTSA has considered the effects of this
action under the Regulatory Flexibility Act. I
hereby certify that it will not have a significant
economic impact on a substantial number of small
entities. School bus manufacturers are generally
not small businesses within the meaning of the
Regulatory Flexibility Act. Small governmental
units and small organizations are generally
affected by amendments to the Federal motor
vehicle safety standards as purchasers of new
school buses. However, as discussed above, such
entities that purchase school buses should see lit-
tle change with regard to the price of new buses
that are equipped with compliant mirrors. In addi-
tion, the agency notes that less than six mirror
manufacturers provide nearly all of the school bus
mirrors in use today. Although they are small
companies, each has a full product line, including
mirrors that can meet the amended standard.
' Thus, the likely impact should only be a shift in
sales of particular mirror types. Accordingly, the

agency has determined that preparation of a regu-
latory flexibility analysis is unnecessary.

Executive Order 12612 (Federalism)

This rulemaking has been analyzed in accord-
ance with the principles and criteria contained in
Executive Order 12612, and NHTSA has deter-
mined that it does not have sufficient federalism
implications to warrant preparation of a Federal-
ism Assessment.

In its analysis, the agency considered the
amendment's likely effect on the States and pos-
sible alternatives to the rulemaking. The agency
has determined that virtually all States require
school buses to be equipped with more mirrors
than current Standard No. 1 1 1 requires. As this
preamble explained earlier, the amendment pro-
vides general performance-oriented requirements
that the States may exceed. Although the amend-
ments will supersede the current school bus mir-
ror requirements of a large number of States, any
required State regulatory changes will only
involve a relatively minor administrative or legis-
lative action that should not require extensive
discussion or debate, since the change will
improve the level of driver visibility. In addition,
because the amendment eliminates current spe-
cific requirements which serve to prohibit certain
mirror designs, the rulemaking provides additional
flexibility to the States. The agency further notes
that the amended requirements are similar to the
recommendation approved by 86 percent of the
State representatives at the 11th National Con-
ference on School Transportation. In addition.
State commenters to the NPRM favored the field-
of-view requirements. NHTSA accordingly does
not expect any significant adverse effect on the
States as a result of this rulemaking.

National Environmental Policy Act

NHTSA has also analyzed this rulemaking
action for purposes of the National Environmental
Policy Act. The agency has determined that
implementation of this action will not have any
significant impact on the quality of the human
envirormient. Although there will likely be an
increase in production of certain mirror types, this
increase will not introduce any new or particu-
larly harmful effects to the environment.

PART 571: S111-PRE-5I

Part 571— Federal Motor Vehicle Safety Stand-
ards

In consideration of the foregoing, 49 CFR part
57 1 is amended, as follows:

1 . The authority citation for part 57 1 of title 49
continues to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403,
1407; delegation of authority at 49 CFR 1.50.

§571.111 [Amended]

2. In §571.111, S4 is amended by adding the
following definition in alphabetical order.

=f: * * * *

Effective minor surface means the portions of
a mirror that reflect images, excluding the mirror
rim or mounting brackets.

*****

3. In §571.111, S9 through S9.2(b) is revised
and a new S9.3 through S9.4(b)(2) is added, to
read as follows:

S9. Requirements for School Buses. When a
school bus is tested in accordance with the proce-
dures of SI 3, it shall meet the requirements of
S9.1 through S9.4.

59.1 Outside Rearview Mirrors. Each school
bus shall have two outside rearview mirror sys-
tems: System A and System B.

59.2 System A shall be located with stable
supports so that the portion of the system on the
bus's left side, and the portion on its right side,
each:

(a) Includes at least one mirror of unit mag-
nification with not less than 322.60 square centi-
meters (50 square inches) of reflective surface;
and

(b) Includes one or more mirrors which
together provide, at the driver's eye location, a
view of:

(1) For the mirror system on the right side
of the bus, the entire top surface of cylinder N
in Figure 2, and of that area of the ground
which extends rearward from the mirror surface
not less than 60.93 meters (200 feet).

(2) For the mirror system on the left side of
the bus, the entire top surface of cylinder M in
Figure 2, and of that area of the ground which
extends rearward from the mirror surface not
less than 60.93 meters (200 feet).

S9.3(a) For each of the cylinders A through P
whose entire top surface is not directly visible

from the driver's eye location, System B shall
provide, at that location:

(1) A view of the entire top surface of that
cylinder.

(2) A view of the ground that overlaps with
the view of the ground provided by system A.

(b) Each mirror installed in compliance with
S9.3(a) shall meet the following requirements:

(1) Each mirror shall have a projected area
of at least 258.08 square centimeters (40 square
inches), as measured on a plane at a right angle
to the mirror's axis.

(2) Each mirror shall be located such that the
distance from the center point of the eye loca-
tion of a 25th percentile adult female seated in
the driver's seat to the center of the mirror
shall be at least 95.25 centimeters (37.5
inches).

(3) Each mirror shall have no discontinuities
in the slope of the surface of the mirror.

(4) Each mirror system shall be installed
with a stable support designed to dampen
vibration.

(c) Each school bus which has a mirror
installed in compliance with S9.3(a) that has an
average radius of curvature of less than 88.90
centimeters (35 inches), as determined under SI 2,
shall have a label visible to the seated driver. The
label shall be printed in a type face and color that
are clear and conspicuous. The label shall state
the following:

S9.4(a) Each image required by S9.3(a)(l) to
be visible at the driver's eye location shall be
separated from the edge of the effective mirror
surface of the mirror providing that image by a
distance of not less than 3 minutes of arc.

(b) The image required by S9.3(a)(l) of cyl-
inder P shall meet the following requirements:

(1) The angular size of the shortest dimen-
sion of that cylinder's image shall be not less
than 3 minutes of arc; and

(2) The angular size of the longest dimension
of that cylinder's image shall be not less than
9 minutes of arc.

PART 571; Slll-PRE-52

4. Section 571.111 is amended by adding a
new S13 through SI 3.6, to read as follows:

SI 3. School bus minor test procedures. The
requirements of S9.1 through S9.4 shall be met
when the vehicle is tested in accordance with the
following conditions.

513.1 The cylinders shall be a color which
provides a high contrast with the surface on
which the bus is parked.

51 3.2 The cylinders are 0.3048 meters (1
foot) high and 0.3048 meters (1 foot) in diameter,
except for cylinder P which is 0.9114 meters (3
feet) high and 0.3048 meters (1 foot) in diameter.

51 3.3 Place cylinders at locations as specified
in SI 3.3(a) through SI 3.3(g) and illustrated in
Figure 2. Measure the distances shown in Figure
2 from a cylinder to another object from the cen-
ter of the cylinder as viewed from above.

(a) Place cylinders G, H, and I so that they are
tangent to a transverse vertical plane tangent to
the forward-most surface of the bus's front
bumper. Place cylinders D, E, F so that their cen-
ters are located in a transverse vertical plane that
is 1.8288 meters (6 feet) forward of a transverse
vertical plane passing through the centers of cyl-
inders G, H, and I. Place cylinders A, B, and C
so that their centers are located in a transverse
vertical plane that is 3.6576 meters (12 feet) for-
ward of the transverse vertical plane passing
through the centers of cylinders G, H, and I.

(b) Place cylinders B, E, and H so that their
centers are in a longitudinal vertical plane that
passes through the bus's longitudinal centerline.

(c) Place cylinders A, D, and G so that their
centers are in a longitudinal vertical plane that is
tangent to the most outboard edge of the left side
of the bus's front bumper.

(d) Place cylinders C, F. and I so that their cen-
ters are in a longitudinal vertical plane that is tan-

gent to the most outboard edge of the right side
of the bus's front bumper.

(e) Place cylinder J so that its center is in a
longitudinal vertical plane 0.3048 meters (1 foot)
to the left of the longitudinal vertical plane pass-
ing through the centers of cylinders A, D, and G,
and is in the transverse vertical plane that passes
through the centerline of the bus's front axle.

(f) Place cylinder K so that its center is in a
longitudinal vertical plane 0.3048 meters (1 foot)
to the right of the longitudinal vertical plane pass-
ing through the centers of cylinders C, F, and I,
and is in the transverse vertical plane that passes
through the centerline of the bus's front axle.

(g) Place cylinders L, M, N, O, and P so that
their centers are in the transverse vertical plane
that passes through the centerline of the bus's rear
axle. Place cylinder L so that its center is in a
longitudinal vertical plane that is 1.8288 meters (6
feet) to the left of the longitudinal vertical plane
tangent to the bus's most outboard left surface
(excluding the mirror system). Place cylinder M
so that its center is in a longitudinal vertical plane
that is 0.3048 meters (1 foot) to the left of the
longitudinal vertical plane tangent to the left side
of the bus. Place cylinder N so that its center is
in a longitudinal vertical plane that is 0.3048
meters (1 foot) to the right of the longitudinal
vertical plane tangent to the right side of the bus.
Place cylinder O so that its center is in a longitu-
dinal vertical plane that is 1.8288 meters (6 feet)
to the right of the longitudinal vertical plane tan-
gent to the right side of the bus. Place cylinder
P so that its center is in a longitudinal vertical
plane that is 3.6576 meters (12 feet) to the right
of the longitudinal vertical plane tangent to the
right side of the bus.

PART 571: Slll-PRE-53

3.6S76m(12ft)
1.6288 m (6 ft)

E F

• •
H I

■ Test Cylinder

•

o • •

L M

• •

Centerline of
Front Axle

N O

Cenierline of
Rear Axle

] 0.3048 md ft) I

3.6576 m (12 ft)

1.6288 m (6 ft)

Figure 2
Location of Test Cylinders for Sciiool Bus Field-of-View Test

PART 571; Slll-PRE-54

15.24 cm (6 in)

Figure 3
Camera Locations for Scliool Bus Field-of-View Test

PART 571; Slll-PRE-55

513.2 The driver's eye location is the eye
location of a 25th percentile adult female, when
seated in the driver's seat as follows:

(a) The center point of the driver's eye location
is the point located 63.58 centimeters (27 inches)
vertically above the intersection of the seat cush-
ion and the seat back at the longitudinal center-
line of the seat.

(b) Adjust the driver's seat to the midway point
between the forward-most and rear-most posi-
tions, and if separately adjustable in the vertical
direction, adjust to the lowest position. If an
adjustment position does not exist at the midway
point, use the closest adjustment position to the
rear of the midpoint. If a seat back is adjustable,
adjust the seat back angle to the manufacturer's
nominal design riding position in accordance with
the manufacturer's recommendations.

513.3 Adjustable minors are adjusted before
the test in accordance with the manufacturer's

recommendations. Such mirrors are not moved or
readjusted at any time during the test.

51 3.4 Place a 35 mm or larger format cam-
era, or video camera, so that its image plane is
located at the center point of the driver's eye
location or at any single point within a semi-
circular area established by a 15.24 centimeter (6
inch) radius parallel to and forward of the center
point (see figure 3). With the camera at any sin-
gle location on or within that semicircle look
through the camera and the windows of the bus
and determine whether the entire top surface of
each cylinder is directly visible.

51 3.5 For each cylinder whose entire top sur-
face is determined under paragraph 13.4 of this
section not to be directly visible at the driver's
eye location,

(a) Place a comparison chart (see figure 4)
above the mirror that provides the fullest view of
the cylinder in situations where a cylinder is par-
tially visible through more than one mirror.

3 minutes 9 minutes

of arc of arc

Not Actual Size

Figure 4.
Comparison Chart for Indirect Field-of-View Measurements

The width of the bars in Figure 4 indicating
three minutes of arc and nine minutes of arc are
derived from the following formula:

For 3 minutes of arc:
X=Dx0.000873,

Where:

X=the width of a line, in the unit of measure-
ment D, representing 3 minutes of arc:

PART 571; Slll-PRE-56

D=distance from center point of driver's eye
location to the center of the mirror's sur-
face; and

0.000873=tangent of 3 minutes of arc.

For 9 minutes of arc:

X=Dx0.002618,

Where:

X=the width of a line, in the unit of measure-
ment D, representing 9 minutes of arc;

D=distance from center point of driver's eye
location to the center of the mirror's sur-
face; and

0.0026 18=tangent of 9 minutes of arc.

(b) Photograph each cylinder through the
mirror(s) that provides a view of the cylinder.
Photograph each cylinder with the camera located

so that the view through its film or image plane
is located at any single location within the semi-
circle established under 13.4, [POINT A,B,C, OR
D] ensuring that the image of the mirror and
comparison chart fill the camera's view finder to
the extent possible.

SI 3.6 Make all observations and take all
photographs with the service/entry door in the
closed position and the stop signal arm(s) in the
fully retracted position.

Issued on: November 24, 1992.

Marion C. Blakey
Administrator.

57 F.R. 57000
December 2, 1992

PART 571; Slll-PRE-57

MOTOR VEHICLE SAFETY STANDARD NO.
Rearview Mirrors

111

51. Scope. This standard specifies requirements
for the performance and location of rearview
mirrors.

52. Purpose. The purpose of this standard is to
reduce the number of deaths and injuries that
occur when the driver of a motor vehicle does not
have a clear and reasonably unobstructed view to
the real.

53. Application. This standard applies to pas-
senger cars, multipurpose passenger vehicles,
trucks, buses, school buses and motorcycles.

54. Definition. Convex mirror means a mirror
having a curved reflective surface whose shape is
the same as that of the exterior surface of a sec-
tion of a sphere.

\_Ejfective mirror surface means the portions of
a mirror that reflect images, excluding the min-or
rim or mounting brackets. (57 F.R. 57000 — Decem-
ber 2, 1992. Effective: December 2, 1993)]

Unit magnification mirror means a plane or flat
mirror with a reflective surface through which the
angular height and width of the image of an
object is equal to the angular height and width of
the object when viewed directly at the same dis-
tance except for flaws that do not exceed normal
manufacturing tolerances. For the purposes of this
regulation a prismatic day-night adjustment rear-
view mirror one of whose positions provides unit
magnification is considered a unit magnification
mirror.

55. Requirements for passenger cars.

S5.1. Inside rearview mirror. Each passenger
car shall have an inside rearview mirror of unit
magnification.

S5.1.1. Field of view. Except as provided in
S5.3, the mirror shall provide a field of view with
an included horizontal angle measured from the
projected eye point of at least 20 degrees, and
sufficient vertical angle to provide a view of a

level road surface extending to the horizon begin-
ning at a point not greater than 200 feet to the rear
of the vehicle when the vehicle is occupied by the
driver and four passengers or the designed occu-
pant capacity, if less, based on an average occu-
pant weight of 150 pounds. The line of sight may
be partially obscured by seated occupants or by
head restraints. The location of the driver's eye
reference points shall be those established in
Motor Vehicle Safety Standard No. 104
(§571.104) or a nominal location appropriate for
any 95th percentile male driver.

S5.1.2. Mounting. The mirror mounting shall
provide a stable support for the mirror, and shall
provide for mirror adjustment by tilting in both the
horizontal and vertical directions. If the mirror is
in the head impact area, the mounting shall
deflect, collapse or break away without leaving
shaip edges when the reflective surface of the mir-
ror is subjected to a force of 90 pounds in any for-
ward direction that is not more than 45° from the
forward longitudinal direction.

S5.2. Outside rearview mirror — driver's side.

55.2.1. Field of view. Each passenger car shall
have an outside mirror of unit magnification. The
mirror shall provide the driver a view of a level
road surface extending to the horizon from a line,
perpendicular to a longitudinal plane tangent to
the driver's side of the vehicle at the widest point,
extending 8 feet out from the tangent plane 35 feet
behind the driver's eyes, with the seat in the rear-
most position. The line of sight may be partially
obscured by the rear body or fender contours. The
location of the driver's eye reference points shall
be those established in Motor Vehicle Safety
Standard No. 104 (§571.104) or a nominal loca-
tion appropriate for any 95th percentile male
driver.

55.2.2. Mounting. The mirror mounting shall
provide a stable support for the mirror, and neither
the mirror nor the mounting shall protrude farther

PART 571; S 111-1

(Rev. 12/2/92)

than the widest part of the vehicle body except to
the extent necessary to produce a field of view
meeting or exceeding the requirements of S5.2.1.
The mirror shall not be obscured by the unwiped
portion of the windshield, and shall be adjustable
by tilting in both horizontal and vertical directions
from the driver's seated position. The mirror and
mounting shall be free of sharp points or edges
that could contribute to pedestrian injury.

55.3. Outside rearview mirror passenger's
side. Each passenger car whose inside rearview
mirror does not meet the field of view require-
ments of S5.1.1 shall have an outside mirror of
unit magnification or a convex mirror installed on
the passenger's side. The mirror mounting shall
provide a stable support and be free of sharp
points or edges that could contribute to pedestrian
injury. The mirror need not be capable of adjust-
ment by tilting in both horizontal and vertical
directions.

55.4. Convex mirror requirements. Each motor
vehicle using a convex mirror to meet the require-
ments of S5.3 shall comply with the following
requirements:

55.4.1. When each convex mirror is tested in
accordance with the procedures specified in S12
of this standard, none of the radii of curvature
readings shall deviate from the average radius of
curvature by more than plus or minus 12.5 per-
cent.

55.4.2. Each convex mirror shall have perma-
nently and indelibly marked at the lower edge of
the mirror's reflective surface, in letters not less
than V\6 inch or more than V4 inch high, the
words "Objects in MiiTor Are Closer Than They
Appear." (48 F.R. 38842— August 26, 1983. Effec-
tive: August 26, 1983)

55.4.3. The average radius of curvature of each
such mirror, as determined by using the procedure
in SI 2, shall be not less than 35 inches and not
more than 65 inches.

56. Requirements for multipurpose pas-
senger vehicles, trucks, and buses, other than
school buses, with GVWR of 10,000 pounds or
less.

S6.1. Each multipurpose passenger vehicle, truck
and bus, other than a school bus, with a GVWR
of 10,000 pounds or less shall have either —

(a) Mirrors that conform to the requirements of
S5; or

(b) Outside minors of unit magnification, each
with not less than 19.5 in- of reflective surface,
installed with stable supports on both sides of the
vehicle, located so as to provide the driver a view
to the rear along both sides of the vehicle, and
adjustable in both the horizontal and vertical
directions to view the rearward scene.

57. Requirements for multipurpose pas-
senger vehicles and trucks with a GVWR of
more than 10,000 and less than 25,000 pounds
and buses, other than school buses, with a
GVWR of more than 10,000 pounds.

S7.1. Each multipurpose passenger vehicle and
trucks with a GVWR of more than 10,000 pounds
and less than 25,000 pounds and each bus, other
than a school bus, with a GVWR of more than
10,000 pounds shall have outside mirrors of unit
magnification, each with not less than 50 in- of
reflective surface, installed with stable supports on
both sides of the vehicle. The mirrors shall be
located so as to provide the driver a view to the
rear along both sides of the vehicle and shall be
adjustable both in the horizontal and vertical
directions to view the rearward scene.

58. Requirements for multipurpose pas-
senger vehicles and trucks with a GVWR of
25,000 pounds or more.

S8.1. Each multipurpose passenger vehicle and
truck with a GVWR of 25,000 pounds or more
shall have outside mirrors of unit magnification,
each with not less than 50 in- of reflective surface,
installed with stable supports on both sides of the
vehicle. The mirrors shall be located so as to pro-
vide the driver a view to the rear along both sides
of the vehicle and shall be adjustable both in the

(Rev. 8/26/83)

PART 571; S 111-2

horizontal and vertical directions to view the rear-
ward scene.

[S9. Requirements for School Buses. When a
school bus is tested in accordance with the proce-
dures of SI 3, it shall meet the requirements of
S9.1 through S9.4.

59.1 Outside Rearview IVIirrors. Each school
bus shall have two outside rearview mirror sys-
tems: System A and System B.

59.2 System A shall be located with stable sup-
ports so that the portion of the system on the bus's
left side, and the portion on its right side, each:

(a) Includes at least one minor of unit mag-
nification with not less than 322.60 square centi-
meters (50 square inches) of reflective surface;
and

(b) Includes one or more mirrors which
together provide, at the driver's eye location, a
view of:

59.3 (a) For each of the cylinders A through P
whose entire top surface is not directly visible
from the driver's eye location. System B shall pro-
vide, at that location:

( 1 ) A view of the entire top surface of that
cylinder.

(2) A view of the ground that overlaps with
the view of the ground provided by system A.
(b) Each mirror installed in compliance with

S9.3(a) shall meet the following requirements:

(1) Each mirror shall have a projected area
of at least 258.08 square centimeters (40 square
inches), as measured on a plane at a right angle
to the mirror's axis.

(3) Each mirror shall have no discontinuities
in the slope of the surface of the mirror.

(4) Each mirror system shall be installed
with a stable support designed to dampen
vibration.

S9.4 (a) Each image required by S9. 3(a)(1) to be
visible at the driver's eye location shall be sepa-
rated from the edge of the effective mirror surface
of the mirror providing that image by a distance
of not less than 3 minutes of arc.

(b) The image required by S9.3(a)(l) of cyl-
inder P shall meet the following requirements:

(1) The angular size of the shortest dimen-
sion of that cylinder's image shall be not less
than 3 minutes of arc; and

(2) The angular size of the longest dimension
of that cylinder's image shall be not less than
9 minutes of arc. (57 F.R. 57000— December 2,

1992. Effective: December 2. 1993)]

510. Requirements for motorcycles.

S10.1. Each motorcycle shall have either a mirror
of unit magnification with not less than 12.5 in-
of reflective surface, or a convex mirror with not
less than 10 in' of reflective surface and an aver-
age radius of curvature not less than 20 inches and
not greater than 60 inches, installed with a stable
support, and mounted so that the horizontal center
of the reflective surface is at least 1 1 inches out-
ward of the longitudinal centerline of the motor-
cycle. The mirror shall be adjustable by tilting in
both the horizontal and vertical directions.

511. Mirror construction. The average reflec-
tance of any mirror required by this standard shall
be determined in accordance with SAE Rec-

PART57I; S 111-3

(Rev. 12/2/92)

ommended Practice J964, October 1984. All sin-
gle reflectance mirrors shall have an average
reflectance of at least 35 percent. If a miiTor is
capable of multiple reflectance levels, the mini-
mum reflectance level in the day mode shall be at
least 35 percent and the minimum reflectance
level in the night mode shall be at least 4 percent.
A multiple reflectance mirror shall either be
equipped with a means for the driver to adjust the
mirror to a reflectance level of at least 35 percent
in the event of electrical failure, or achieve such
reflectance level automatically in the event of
electrical failure.

SI 2. Determination of Radius of Curvature.

SI 2.1. To determine the average radius of cur-
vature of a convex mirror, use a 3-point linear
spherometer, which meets the requirements of
S12.2., at the 10 test positions shown in Figure 1
and record the readings for each position.

Figure 1.

-Location of Ten Convex Mirror
Testing Positions

512.2. The 3-point Hnear spherometer has two
outer fixed legs 1.5 inches apart and one inner
movable leg at the midpoint. The spherometer has
a dial indicator with a scale that can be read
accurately to 0.0001 inches, with the zero reading
being a flat surface.

512.3. The 10 test positions on the image display
consist of two positions at right angles to each
other at each of five locations as shown in Figure
1 . The locations are at the center of the mirror, at
the left and right ends of a horizontal line that
bisects the mirror and at the top and bottom ends
of a vertical line that bisects the mirror. None of
the readings are within 0.25-inch border on the
edge of the image display.

SI 2.4. At each test position, the spherometer is
held perpendicular to the convex mirror-surface

and a record is made of the reading on the dial
indicator to the nearest 0.0001 inch.

S12.5. Convert the dial reading data for each of
the 10 test positions to radius of curvature calcula-
tions using Table I. Consider the change as linear
for dial readings that fall between two numbers in
Table I.

Table I — Conversion Table From Spherometer
Dial Reading To Radius of Curvature

Dial reading

Radius of curvature
(in inches)

.00330

85.2

.00350

80.4

.00374

75.2

.00402

70.0

.00416

67.6

.00432

65.1

.00450

62.5

.00468

60.1

.00476

59.1

.00484

58.1

.00492

57.2

.00502

56.0

.00512

54.9

.00522

53.9

.00536

52.5

.00544

51.7

.00554

50.8

.00566

49.7

.00580

48.5

.00592

47.5

.00606

46.4

.00622

45.2

.00636

44.2

.00654

43.0

.00668

42.1

.00686

41.0

.00694

40.5

.00720

39.1

.00740

38.0

.00760

37.0

.00780

36.1

.00802

35.1

.00822

34.2

.00850

33.1

.00878

32.0

.00906

31.0

.00922

30.5

.00938

30.0

.00960

29.3

.00980

28.7

.01004

28.0

.01022

27.5

.01042

27.0

.01060

26.5

.01080

26.0

.01110

25.3

.01130

24.9

.01170

24.0

.01200

23.4

.01240

22.7

.01280

22.0

.01310

21.5

.01360

20.7

.01400

20.1

.01430

19.7

.01480

19.0

.01540

18.3

.01570

17.9

.01610

17.5

.01650

17.1

.01700

16.6

.01750

16.1

.01800

15.6

.01860

15.1

(Rev. 12/2/92)

PARI' 571; S i:

Table I — Conversion Table From Spherometer
Dial Reading To Radius of Curvature-
Continued

Dial reading

Radius of curvature
(in inches)

.01910

14.7

.01980

14.2

.02040

13.8

.02100

13'4

.02160

13.0

.02250

12.5

.02340

12.0

.02450

11.5

.02560

11.0

.02680

10.5

.02810

10.0

.02960

9.5

.03130

9.0

.03310

8.5

SI 2.6. Calculate the average radius of curvature
by adding all 10 radius of curvature calculations
and dividing by ten.

512.7. Determine the numerical difference
between the average radius of curvature and each
of the 10 individual radius of curvature calcula-
tions determined in S12.5.

512.8. Calculate the greatest percentage deviation
by dividing the greatest numerical difference
determined in S12.7 by the average radius of cur-
vature and multiply by 100.

[S13. School bus mirror test procedures. The

requirements of S9.1 through S9.4 shall be met
when the vehicle is tested in accordance with the
following conditions.

513.1 The cylinders shall be a color which pro-
vides a high contrast with the surface on which
the bus is parked.

513.2 The cylinders are 0.3048 meters (1 foot)
high and 0.3048 meters (1 foot) in diameter,
except for cylinder P which is 0.9114 meters (3
feet) high and 0.3048 meters (1 foot) in diameter.

SI 3.3 Place cylinders at locations as specified in
SI 3.3(a) through SI 3.3(g) and illustrated in Figure
2. Measure the distances shown in Figure 2 from
a cylinder to another object from the center of the
cylinder as viewed from above.

is 1.8288 meters (6 feet) forward of a transverse
vertical plane passing through the centers of cyl-
inders G, H, and I. Place cylinders A, B, and C
so that their centers are located in a transverse
vertical plane that is 3.6576 meters (12 feet) for-
ward of the transverse vertical plane passing
through the centers of cylinders G, H, and I.

(b) Place cylinders B, E, and H so that their
centers are in a longitudinal vertical plane that
passes through the bus's longitudinal centerline.

(c) Place cylinders A, D, and G so that their
centers are in a longitudinal vertical plane that is
tangent to the most outboard edge of the left side
of the bus's front bumper.

(d) Place cylinders C, F, and I so that their cen-
ters are in a longitudinal vertical plane that is tan-
gent to the most outboard edge of the right side
of the bus's front bumper.

PART 571; S 111-5

(Rev. 12/2/92)

right side of the bus. (57 F.R. 57000— December 2,
1992. Effective: December 2, 1993)]

16578111(12 ft)

i.ann(6ft)

] 0-J048m(lft) I 3.6576ni(12fl

INTERPRETATION

(1) When a supplemental mirror is furnished in
addition to the inside rearview mirror and the
driver's side outside rearview mirror, the supple-
mental mirror need not be adjustable from the
driver's seat.

(2) The location of the driver's eye reference
point may be that established in Motor Vehicle
Safety Standard No. 104, or it may be a nominal
location appropriate for any 95th percentile male
driver.

(3) The horizontal angle is measured from the
projected eye point, rather than the plane of the
mirror.

32 F.R. 2413
February 3, 1967

Figure 2.— Location of Test Cylinders for
School Bus Field-of-View Test

Figure 3. — Camera Locations for School Bus
Field-of-View Test

PARI' 571; S 111-6

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE

SAFETY STANDARD NO. 121

Air Brake Systems

(Docket No. 85-07; Notice 7)
RIN: 2127-AD-27

ACTION: Final rule.

SUMMARY: This rule amends the pneumatic tim-
ing requirements of Standard No. 121, Air Brake
Systems, with respect to the control line pressure
balance. Specifically, the agency is adopting a
new dynamic test procedure for determining the
control signal pressure differential. These amend-
ments are part of a more general rulemaking to
improve the brake timing balance of combination
vehicles and partially implement the mandate in
section 4012 of the Intermodal Surface Transpor-
tation Efficiency Act (ISTEA) regarding rule-
making for "improving brake compatibility [and]
effectiveness of brake timing."

EFFECTIVE DATE: The amendments become
effective on August 23, 1992. Vehicles manufac-
tured before the effective date may comply with
this rule's amendments, effective September 21,
1992.

SUPPLEMENTARY INFORMATION:

Pneumatic timing is an important factor in air
brake system performance. The time required for
a vehicle's service brake chambers to reach a rel-
atively high pressure level after actuation of the
brake control by the driver is referred to as
"pneumatic application time." Since the genera-
tion of braking force is directly related to the air
pressure available in the brake chambers, pneu-
matic application time affects vehicle stopping
distance. As a general matter, the shorter the
pneumatic application time, the shorter the
vehicle's stopping distance.

The pneumatic application timing can affect the
stability of combination vehicles. If a trailer's
brakes apply more slowly on the towing vehicle's
brakes, the trailer can bump the towing vehicle.

applying an excessive compressive force on the
kingpin connecting the trailer to the towing
vehicle. If the brakes are applied during a turn,
this force may reduce the stability of the com-
bination and contribute to a jackknife accident.

Braking performance is also affected by "pneu-
matic release timing" (i.e., the time required for
the pressure in the brake chambers to fall from a
relatively high pressure to a relatively low pres-
sure after the driver releases the brake control). If
a vehicle's wheels lock as the driver is attempting
to stop, the vehicle will skid. The driver must be
able to release the brakes immediately to regain
control of the vehicle in this situation.

For combination vehicles, pneumatic release
timing can affect stability. If a towing vehicle's
brakes release more slowly than the trailer's,
destabilizing forces may increase at the kingpin.

Standard No. 121, Air Brake Systems, currently
specifies certain requirements for pneumatic tim-
ing. Section S5.3.3 specifies time periods within
which brake actuation for trucks, buses, and trail-
ers must occur. Similarly, section S5.3.4 specifies
time periods within which brake release for these
vehicles must occur.

The timing tests for trailers, including trailer
converter dollies, are conducted with the trailer
connected to a test rig rather than an actual trac-
tor. The test rig delivers air to, and releases air
from, the trailer during the timing test. The timing
tests for vehicles designed to tow trailers are con-
ducted with a 50-cubic-inch reservoir connected
to the rear control line coupling. This reservoir
represents the control line volume of the towed
trailer.

Regulatory Background
On May 3, 1989, NHTSA published a final
rule amending Federal Motor Vehicle Safety
Standard No. 121, Air Brake Systems, to improve

PART 571: S121— PRE-223

the timing balance of combination vehicles (54
FR 13890).

SNPRM I

On that same day, NHTSA published a Supple-
mental Notice of Proposed Rulemaking (SNPRM)
proposing two further amendments concerning
pneumatic timing (54 FR 18912). The first pro-
posal would have required the actuation time at
the gladhand to be at least as fast as the timing
at the brake chambers. However, after reviewing
the comments on this issue, NHTSA decided to
terminate this portion of the rulemaking because
the proposed requirement would have reduced
flexibility in product manufacturing by requiring
more custom design of vehicles. In addition, the
costs resulting from such a requirement would not
have been justified in view of the relatively lim-
ited safety benefits associated with such a require-
ment.

The second proposal would have required that
the relay booster valves used on towing trailers
not upset the brake balance of combination
vehicles. The second proposal was intended to
allay NHTSA's concern about excessive control
line pressure differentials in multiple trailer com-
binations. Another concern was that pressure dif-
ferentials, which could be caused by relay booster
valves with overly high crack pressures (i.e., the
pressure at which a booster relay valve opens),
could create situations in which the brakes of
only the towing trailer were actuated. For exam-
ple, if the crack pressure were too high, the relay
booster valve would not open during mild brak-
ing, and the brakes of the towed trailer would not
be actuated.

NHTSA proposed to require that, in all situa-
tions in which the pressure at the input coupling
is steady (or is increasing or decreasing at a rate
of 10 psi per minute or less), the pressure dif-
ferential between the control line gladhand at the
front of a towing trailer and the control line glad-
hand at the rear of the trailer not exceed 1.0 psi
at input pressures between 5.0 and 20.0 psi, and
not exceed 2.0 psi at input pressures above 20.0
psi. The agency believed that the requirement
would ensure that the brakes of both the towing
trailer and the towed trailer would receive the
same signal.

SNPRM II

After reviewing the comments to the first
SNPRM, the agency published a second supple-

mental notice of proposed rulemaking (SNPRM)
on March 15, 1991 (56 FR 11150). As mentioned
above, the agency decided to terminate the por- i^^
tion of the rulemaking about gladhand actuation ^*
timing. As for the proposal about control line
pressure differential, NHTSA decided to propose
modified requirements.

The commenters generally agreed in theory that
control line pressure differential should be con-
trolled. However, commenters stated that the pro-
posed requirements were inappropriate. Bendix
Heavy Vehicle Systems Group (Bendix) stated
that the proposed 10 psi per minute rate of pres-
sure change was extremely slow and would be
difficult to maintain over a wide pressure range.
Bendix also stated that the proposed rate was not
representative of normal pressure changes that
occur during braking.

Bendix suggested an alternative test procedure
using two specific test orifices with fixed diame-
ters and thickness to control flow rates. Bendix
recommended that the test orifice sizes be set at
0.0180 inches diameter for application timing and
0.0292 inches diameter for release timing. Bendix
believed that these diameters would produce
brake pressure rates that are consistent with lower
limit applications, such as those required for ^
maintaining vehicle speed on a five percent grade.
Bendix recommended four psi per second for
application and release testing, a rate substantially
faster than the one proposed by NHTSA in the
first SNPRM, but closer to rates seen in actual
service applications. Bendix also suggested that
the testing procedure for detemiining the control
signal pressure differential on towing trailers and
dollies use either of the current Standard No. 121
trailer test rigs and an orifice fixture, coupled
between the control line gladhand of the trailer
test rig and the control line input coupling of the
vehicle to be tested.

After reviewing Bendix's suggested pressure
differential test, NHTSA decided to propose a
simplified test procedure that would use only one
metering orifice, i.e., the smaller of the two ori-
fices suggested by Bendix. While Bendix claimed
that the use of two orifices would result in the
same pressure change rate for both apply and
release, NHTSA did not believe that monitoring
the same pressure change rate was necessary. The
agency believed that using one rather than two ^
orifices would avoid the very fast or very slow "
pressure rate rises that could be problematic.

PART 571; S121— PRE-224

NHTSA anticipated that the apply rate would
approximate four psi per second, but the release
rate would be somewhat slower.

The second SNPRM explained that the pro-
posed pressure differential test slowly "sweeps"
the pressure across the full range of operating
pressures, thus enabling the person conducting the
test to check the differential level. The orifice
restricts the flow from the trailer test rig and
slows the pressure rise and decay rate. The ability
to "sweep" the pressure slowly makes it
unnecessary to stop and hold the pressure con-
stant. If the pressure is changed too rapidly, the
steady state case (i.e., when brake pressure is
being held steady after application of the brakes)
is not evaluated and pressure differentials caused
by air flow through the control lines, instead of
valve characteristics, are introduced.

NHTSA tentatively concluded that the proposal
concerning control line pressure differential was
necessary to meet the need for motor vehicle
safety. NHTSA believed that some trailer manu-
facturers would install relay valves at the rear of
the trailers in the control lines upstream of the
towing gladhands to "boost" the control signal.
This would result in a significant margin of
compliance with the new brake timing require-
ments for towing trailers established by NHTSA
in the May 3, 1989 final rule.

In response to the second SNPRM, the agency
received four comments. They were submitted by
Midland-Grau, Bendix Heavy Vehicle Systems,
the Truck Trailer Manufacturers Association
(TTMA), and Mr. Robert Crail, a consultant. The
agency has considered the points raised in the
comments in developing this final rule. The com-
menters' significant points are addressed below,
along with the agency's response to the com-
ments.

Agency's Determination
1 . Safety Need

Midland-Grau questioned the safety need for
the proposal, stating that "Since there is no
identified relationship between the control line
pressure and brake force exerted, there appears to
be no justification for the great efforts needed to
achieve tightly tracking control line pressures."

NHTSA agrees with Midland-Grau that there is
no absolute relationship between control line pres-
sure and brake force. Nevertheless, by ensuring
that the pressures will be constant as they are

passed to other vehicles in combinations, this
rulemaking will alleviate one significant source of
combination vehicle brake imbalance. Therefore,
the commenler's concern about the nonexistence
of such a relationship has no bearing on the
imbalance problem.

NHTSA notes that this rulemaking action to
add requirements for control line pressure balance
was intended to be a small but important part of
the general rulemaking package regarding timing
changes (see docket No. 85-07; Notice 3). There-
fore, in detennining the safety benefits derived
from the control line pressure amendment, the
safety benefits obtained from the more general
timing amendments should be considered to some
extent. The agency continues to believe that the
amendment about control line pressure should be
adopted because, without this provision, an imbal-
ance problem could exist if a manufacturer
installed relay booster valves which speeded up
the timing to meet the new timing requirements.

The amendment is designed to ensure that the
control signal "passes" through a towing trailer
or dolly without being altered along the way.
Because the control signal passes through
unaltered, each vehicle in the combination unit
receives the same brake control signal (i.e., by
keeping the control signal at the same level, each
vehicle in a combination has a comparable brak-
ing performance). The agency acknowledges that
Standard No. 121 does not specifically address
brake force as a function of control pressure.
Nevertheless, the Society of Automotive Engi-
neers (SAE) developed SAE Recommended Prac-
tice J 1854 and Test Procedure J 1505 to allay con-
cerns about incompatibility. The agency believes
that this rulemaking will act in conjunction with
SAE J 1854 to improve compatibility between
vehicles.

2. Test Procedure

The second SNPRM proposed a dynamic test
procedure in which pressure differential is evalu-
ated using a single metering orifice. TTMA and
Mr. Crail favored a test procedure measuring
static conditions. TTMA believed that such a test
procedure would be more similar to actual brak-
ing and would be less costly.

Notwithstanding these comments, the agency
favors a dynamic test procedure which slowly
sweeps across the full range of pressures. The
agency notes that NHTSA's Vehicle Research and

PART 571; SI21— PRE-225

Test Center (VRTC) conducted tests which
indicated that the proposed dynamic test appro-
priately evaluated control pressure differential.
These tests were designed to measure the control
line pressure valve's influence on the control line
pressure to ensure that the pressure is not ampli-
fied. When such pressure is amplified, the pres-
sure may not properly "bleed" back to the stable
level, and thus adversely affect the timing among
vehicles in a combination. The testing compared
the pressure between the gladhand at the front of
a towing trailer and the gladhand at the rear. The
agency does not believe that the pressure differen-
tial problem which may arise through increased
use of relay booster valves can be controlled with
a static pressure test. Performing the necessary
testing is technologically sensitive because the
pressure between the gladhand in front of a tow-
ing trailer must be compared with the pressure at
the rear gladhand. Given that the test sequence of
events between the front gladhand and the rear
gladhand occurs very rapidly and at pressure dif-
ferentials too small for human observers to record
the event accurately, the devices recommended by
some commenters would be incapable of measur-
ing such an intricate situation.

Mr. Crail commented that tolerances are needed
in the test requirements, claiming that it is impos-
sible to measure pressure exactly. He indicated
that pressure accuracy within a range of ± 0.25
psi would be appropriate.

NHTSA notes that the agency generally does
not specify tolerances in a requirement since a
minimum or maximum value does not need a
tolerance. The test values specified in the
changes, as adopted, are one-sided maximum
specifications in that the pressure differential from
5 to 20 psi cannot exceed 1 psi and at pressures
over 20 psi cannot exceed 2 psi. Accordingly, the
agency has determined that tolerances in the
specified pressures are not necessary.

3. Cost

TTMA and Mr. Crail believed that the amend-
ment's costs would be excessive. TTMA was con-
cerned that the proposed test procedure would
require trailer manufacturers to purchase expen-
sive equipment such as transducers and recording
equipment costing as much as $6,000. In contrast,
it claimed that the equipment necessary for the
static test procedure it favors would cost about
$300 per manufacturer. Mr. Crail stated that the

total cost of the static test would be less than
$900, as compared to approximately $6,000 to
conduct the test proposed by the agency. Simi-
larly, Midland-Grau stated that the proposed
requirements were impractical and unjustifiable.

After conducting its own review, NHTSA
believes that the costs associated with the test
equipment are reasonable and well below the
costs estimated by the commenters. The agency
notes that most trailer manufacturers already own
the most expensive portion of this test equipment
for conducting timing tests (i.e., the data recorder/
power supply/signal conditioning apparatus), and
that the mini-tractor test rigs that are currently
used in compliance testing with Standard No. 121
could be readily upgraded to check for pressure
differentials for an additional cost of $300. Of
this cost figure, $100 would cover the hose, glad-
hands, and air flow restrictor and $200 would
cover the cost of upgrading the software of the
test rig. NHTSA notes that the practical effects of
these requirements are limited to only those trailer
manufacturers who build towing trailers (i.e.,
trailers used in doubles or triples operations).
Such towing trailers currently constitute a very
small percentage of the trailer market.

4. Effective Date

The NPRM proposed an effective date of one
year after the final rule's publication. Bendix
requested that the rule become effective as soon
as possible, claiming that this would limit the
number of vehicles designed to comply with
Notice 3 that would have an undesirable control
pressure differential.

After reviewing the comments, the agency
believes that optional compliance with the control
pressure differential amendments should be per-
mitted beginning 30 days after the final rule's
publication. The agency believes that allowing
earlier optional compliance will reduce the num-
ber of vehicles that may be built with excessive
pressure differentials. Mandatory compliance will
still be effective one year after publication of the
final rule.

PART 571; S121— PRE-226

the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending, or
revoking Federal motor vehicle safety standards.
That section does not require submission of a
petition for reconsideration or other administrative
proceedings before parties may file suit in court.
In consideration of the foregoing, 49 CFR Part
57 1 is amended as follows:

1. The authority citation for Part 571 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403, 1407;
delegation of authority at 49 CFR 1.50.
§571.121 [Amended]

2. S5.3.5 is added to §571.121 to read as fol-
lows:

S5.3.5 Control signal pressure differential —
converter dollies and trailers designed to tow
another vehicle equipped with air brakes.

(a) For a trailer manufactured on or after
[INSERT DATE ONE YEAR AFTER PUBLICA-
TION OF THE FINAL RULE] and designed to
tow another vehicle equipped with air brakes, the
pressure differential between the control line input
coupling and a 50 cubic inch test reservoir
attached to the control line output coupling shall
not exceed the values specified in S5. 3.5(a)(1)
and (2) under the conditions specified in
S5.3.5(b)(l) through (4)—

(1) 1 p.s.i. at all input pressures equal to or
greater than 5 p.s.i., but not greater than 20 p.s.i.;
and

(2) 2 p.s.i. at all input pressures greater than
20 p.s.i.

(b) The requirements in S5.3.5(a) shall be
met —

(1) When the pressure at the input coupling
is steady, increasing or decreasing;

(2) When air is applied to or released from
the control line input coupling using the trailer
test rig shown in Figure 1;

(3) With a fixed orifice consisting of a
0.0180 inch diameter hole (no. 77 drill bit) in a
0.032 inch thick disc installed in the control line
between the trailer test rig coupling and the
vehicle's control line input coupling; and

Issued on August 18, 1992.

Howard M. Smolkin
Executive Director

57 F.R. 37902
August 21, 1992

PART 571; S121—PRE-227

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE
SAFETY STANDARD NO. 121

Air Brake Systems

(Docket No. 91-21; Notice 2)
RIN: 2127-AD-34

ACTION: Final rule.

EFFECTIVE DATES: The amendments to Stand-
ard No. 105 become effective October 20, 1993.

The amendments to Standard No. 121 become
effective October 20, 1994.

SUPPLEMENTARY INFORMATION:

Background

General Information
Proper brake adjustment is critical for maintain-
ing safe stopping performance. Devices known as
automatic brake adjusters automatically maintain
proper brake adjustment, thus eliminating the
need for frequent inspection and manual adjust-
ment of the brakes. Automatic brake adjusters
have been used on passenger cars and light trucks
since the early 1960's and have been standard
equipment on all such vehicles sold in recent
years in the United States. In addition, the vast
majority of medium and heavy duty vehicles with

hydraulic brake systems have automatic brake
adjusters. Automatic brake adjusters were intro-
duced for use on heavy duty air-braked vehicles
in the early 1960's and are widely used today.
The installation rates of automatic brake adjusters
by manufacturers of heavy duty air-braked
vehicles range from 30 to 100 percent of their
fleets.

Safety Need and Practicability of Automatic
Adjustment Devices

Notwithstanding the importance of proper brake
adjustment for maintaining safe stopping perform-
ance, numerous studies have shown that brake
adjustment is not being maintained on some air-
braked medium and heavy duty vehicles that are
not equipped with automatic brake adjusters. (See
Automatic Slack Adjusters for Heavy Vehicle Air
Brake Systems, DOT HS 807 724, February
1991.) When brakes are under-adjusted, stopping
ability is reduced and the probability of a crash
is increased. When brakes are over-adjusted,
maintenance costs and the possibility of a crash
are increased as a result of excessive lining wear,
wheel lock, or brake drum cracking. Such
improper brake adjustment contributes to a
significant number of crashes, including those in
which vehicles are unable to stop in time and
those in which there are "runaways" on steep
mountain grades.

PART 571: S121— PRE-229

tions of heavy truck crashes, and a Federal High-
way Administration study.

Based on the above-mentioned concerns, the
National Transportation Safety Board recom-
mended that NHTSA develop a Federal Motor
Vehicle Safety Standard requiring all newly
manufactured commercial vehicles to have equip-
ment ensuring that brakes are always properly
adjusted.

NHTSA has conducted a large-scale fleet
evaluation to assess the performance and reliabil-
ity of automatic brake adjusters, as compared to
manual adjusters on heavy commercial vehicles
with S-cam air brakes. NHTSA collected brake
adjustment data from several hundred fleet
vehicles equipped with automatic and manual
brake adjusters for approximately five years. The
conclusions regarding the fleet examination are
detailed in the NPRM. Among the principal
conclusions were that:

• The incidence of brake over-adjustment with
automatically-adjusted brakes was low. In the
fleet test, there was no case of an automatic
brake adjuster over-adjusting a brake enough to
cause brake over-heating, wheel lockup, or
excessive brake lining wear.

Automatic Adjusters and Indicators on Air Brake
Systems

There are three principal types of air-braked
systems used in this country: 1) S-cam actuators,
2) wedge type actuators, and 3) disc brakes. For
S-cam brakes, which comprise about 95 percent
of air-brake systems, two major types of auto-
matic brake adjusters are available. One adjusts
on the basis of actual shoe-to-drum clearance. The
other adjusts on the basis of the air chamber push
rod stroke. All wedge type brakes, which com-
prise about three percent of the market, have an
interna! automatic adjustment mechanism. As for
disc brakes which comprise about two percent of
air-brake systems, some have external self-adjust-
ing mechanisms, while others have internal
adjustment features. The external adjustment
mechanism of an air disc brake system operates
similarly to those on S-cam brakes.

Several types of brake adjustment indicators are
currently available. One type involves air brake
chambers with paint markings on push rods that
indicate the level of adjustment. However, such
markings may not be useful in certain applica-
tions (e.g., with wedge brakes when the push rod
is enclosed in a sleeve and with S-cam brakes
having push rods with protective rubber boots). A
second type of brake adjustment indicator is
installed by inserting a guide arm and sliding
stem assembly into a small hole in the air booster
can. A third method involves attaching a hose
clamp to the air chamber push rod to mark the
fully adjusted brake position relative to the air
chamber housing. To check the brake adjustment.

PART 571: S121— PRE-230

the space between the air chamber housing and
hose clamp is compared with a bar gauge.

Notice of Proposed Rulemaking

On May 3, 1991, NHTSA published an NPRM
in which the agency proposed to amend Standard
No. 121 to require automatic brake adjusters and
adjustment indicators on vehicles with air brake
systems. (56 FR 20396) The NPRM also pro-
posed to amend Standard No. 105 to require auto-
matic brake adjusters on vehicles with hydraulic
brake systems. NHTSA decided not to propose
requiring adjustment indicators on hydraulically-
braked vehicles because the agency believed that
there were no significant problems with automatic
brake adjusters for these vehicles or with check-
ing the adjustment of such systems.

Comments to the NPRM and the Agency's
Response

The agency has considered the points raised by
the commenters in developing the final rule. The
agency's discussion of the more significant com-
ments and other relevant information is set forth

below. The notice first addresses issues about
automatic adjusters and indicators on vehicles
equipped with air brakes because the safety prob-
lem primarily involves, and consequently the
agency's rulemaking efforts focus on. these
vehicles. The notice then discusses adjustment
devices on hydraulically-braked vehicles.

Ail- Braked Vehicles
1 . General Considerations

In response to the NPRM's proposal to require
automatic adjusters on air-braked vehicles, all but
one commenter addressing this issue supported
requiring automatic adjusters on air-braked
vehicles. Those supporting the rulemaking
included the American Trucking Associations
(ATA), Truck Trailer Manufacturers Association
(TTMA), General Motors (GM), Ford, and Advo-
cates for Highway and Auto Safety (AHAS).
AHAS stated that the amendments would mitigate
the extent and severity of fatal and injury produc-
ing accidents. Only one commenter, Mr. Robert
Grail, a brake consuhant, disputed the need for
and effectiveness of automatic adjusters on air-
braked vehicles. Mr. Grail stated that automatic
adjusters are not accurate enough to be mandated,
citing raw data about automatic slack adjusters.

Based on the comments and other available
information, NHTSA has determined that requir-
ing automatic adjusters on air-braked vehicles will
improve the brake performance of these vehicles.
As the NPRM explained, out-of-adjustment brakes
pose a significant safety problem that could be
alleviated by requiring automatic brake adjusters.
The agency notes that Mr. Grail's critical com-
ments were based, in part, on raw data gathered
from unscreened sources and uncontrolled test
conditions. Therefore, his conclusions based on
the data are questionable. While NHTSA
acknowledges that older brake adjuster designs
may not perform as well as properly maintained
manual adjusters, the new generation of currently
produced automatic adjusters provide superior
brake adjustment. In addition, even the previous
generation of automatic brake adjusters are often

PART 571: S121— PRE-231

superior to manual adjusters because some owners
of vehicles with manual adjusters do not take the
time to properly adjust or otherwise properly
maintain their brakes.

2. Proposed Regulatory Text

The NPRM proposed amending Standard No.
121 to require all vehicles with air brakes to be
equipped with automatic adjusters. Specifically,
the NPRM proposed that the Standard be amend-
ed to require these devices on trucks, buses, and
trailers, as follows:

"Each vehicle shall be equipped with a serv-
ice brake system acting on all wheels. Wear of
the service brakes shall be compensated for by
means of a system of automatic adjustment,
which maintains brake adjustment within the
manufacturer's recommended adjustment limits.
The condition of service brake adjustment shall
be provided by a brake adjustment indicator
that is discernible when viewed with 20/40
vision, using an ordinary flashlight with two D-
cell batteries from a position 8 feet away on
the adjacent pavement surface. The brake
adjustment indicator shall be capable of
displaying the service brake adjustment condi-
tions of: under-adjustment, over-adjustment,
and fully adjusted within the manufacturer's
specified limits.

a. Brake Adjustment withiii Manufacturer' s
Recommended Adjustment Limits

Several commenters, including White GMC/
Volvo, GM, Ford, Midland-Grau, and a brake
indicator manufacturer, criticized the proposal to
require maintaining brake adjustment within the

manufacturer's recommended adjustment limits.
These commenters believed that the proposal was
unnecessary, ambiguous, and would unreasonably J^
burden manufacturers. GM and Ford stated that
the proposal was potentially ambiguous since
determining what "maintaining brake adjust-
ment" means could be interpreted several ways.
Accordingly, these commenters believed that
some compliance test would be necessary if the
agency adopted this provision. White GMC/
Volvo, GM, and Ford believed that the proposal
might be interpreted as requiring the manufacturer
to be responsible for brake adjustment throughout
the vehicle's life, even though the manufacturer is
typically responsible for compliance only until the
first consumer purchase. In addition, some com-
menters were concerned that the proposal did not
specify an objective measure about the proper
level of adjustment. This consideration led Mid-
land-Grau to recommend that the standard incor-
porate the Federal Highway Administration's
requirements in appendix G to subchapter B of
Chapter III, Title 49, Code of Federal Regula-
tions. FHWA, based on input from the Commer-
cial Vehicle Safety Alliance and brake chamber
manufacturers, has established a set of brake ^
adjustment tables that are published in the North Q
American Uniform Vehicle Out-of-Service Cri-
teria. The States rely on these roadside inspection
tables to place a vehicle out of service if the
adjustment limits are exceeded.

After reviewing the comments and the available
information, NHTSA has determined that the final
rule should not include a reference to maintaining
adjustment within the manufacturer's rec-
ommended limits. The agency agrees with com-
menters that such a provision would not provide
any significant safety benefits but might cause
unnecessary complications and confusion. In
terms of safety benefits, the final rule addresses
the most important issue by requiring each
vehicle to be equipped with a service brake sys-
tem including means for automatic adjustment to
compensate for wear of the system. The reference
to the manufacturer's adjustment limits would
have been superfluous and potentially confusing.
Nevertheless, as explained below, the agency has
decided to reference the FHWA's regulations
about "Vehicle Out-of-Service Criteria." By not
including reference to maintaining adjustment M
based on the manufacturer's recommendations, ^
this amendment is consistent with the proposed

PART 571: S121— PRE-232

requirement about brake adjustment in Standard
No. 135, Passenger Car Brake Systems. (56 FR

\ 30528. July 3. 1991.) Accordingly, the final rule

^ specifies that "Wear of the service brakes shall
be compensated for by means of a system of
automatic adjustment," without reference to a
manufacturer's adjustment limits. The agency
notes that there is no objective criteria as to what
constitutes "maintains adjustment." In addition,
as a general rule, the agency does not establish
extended durability testing. The agency believes
that to require that the adjustment be maintained
throughout the lifetime of the vehicle is unrealis-
tic, dependent upon the vehicle's exposure, and
beyond the scope of NHTSA's authority.

i fied in Appendix G to Subchapter B of Chapter

' III, 49 CFR Parts 200 to 399.

b. Brake Over-adjustment and Under-adjust-
ment

Twelve commenters, primarily heavy brake and
vehicle manufacturers, opposed requiring brake
adjusters to correct for over-adjustment. These
commenters also opposed requiring the brake
adjustment indicators to identify the over-adjusted
and fully adjusted conditions. User groups, such
as the Owner-operator Independent Drivers
Association supported, these proposals. Navistar,
Haldex, Bendix, Midland-Grau, Rockwell, Ford,
k\ the MVMA, Chrysler, Eaton, and the ATA
' believed that requiring the device to control for
over-adjustment and having the adjustment indica-

tor identify this condition were unnecessary and
impracticable. MVMA stated that the incidence of
over- adjustment is very infrequent and poses a
minimal risk to safety. In addition, several manu-
facturers explained that the condition of over-
adjustment can be ascertained by excessive wear,
abuse of the equipment, and, in extreme cases,
smoke. The commenters also stated that the pro-
posal was impracticable because there was no
current technology that reliably indicates the over-
adjusted condition. After reviewing the comments
and available information, NHTSA concludes that
requiring brake adjusters to correct for over-
adjustment and having adjustment indicators show
the over-adjusted and fully-adjusted conditions are
unnecessary for safety and would be impractica-
ble. In terms of the safety need, the fleet evalua-
tion cited in the NPRM concluded that the
incidence of brake over-adjustment was extremely
low. NHTSA further notes that potential problems
associated with over-adjustment will not be
significant. The driver typically will be aware of
over-adjustment because the brake system will
drag and may begin to smoke. In terms of prac-
ticability, the NPRM's tentative determination
about the availability of automatic brake adjusters
to correct for over-adjustment appears to be
inconsistent with the cunent state of brake tech-
nology. The agency now agrees with the com-
ments that regulating over-adjustment would be
impracticable given that such devices are not
readily available. Based on the above, the final
rule does not require brake adjusters to correct for
over-adjustment and does not require the adjust-
ment indicators to show the over-adjusted and
fully-adjusted conditions.

PART 571; SI

this requirement is practicable since there cur-
rently are several devices that are capable of
indicating the under-adjusted condition. Accord-
ingly, Sections 5.1.8 and S5.2.2 are amended to
read, in relevant part, '"(b) Brake indicator. ...the
condition of service brake under-adjustment shall
be provided by a brake adjustment indicator ..."'

c. Visibilit}' Requirements for Brake Adjusters

Several commenters, including Mack, Navistar,
GM, the National Truck Equipment Association
(NTEA), Haldex, the Truck Trailer Manufacturers
Association (TTMA), and Flxible stated that the
proposed visibility requirements were impractica-
ble, especially for those vehicle configurations in
which the line of sight to the air brake chambers
is obscured, hi many vehicles, including buses,
beverage haulers, walk-in vans, ambulances, low-
bed trucks, utility trailers, and tank-trucks, the
brake adjustment indicator may only be inspected
by crawling under a vehicle. Mack explained that
many vehicle configurations make it difficult or
impossible to view the chamber from eight feet
away because brake chambers are frequently
located in positions that are obscured by tires,
hoods, and other vehicle components. In addition,
Rockwell stated that in-service environmental fac-
tors such as mud, salt, and grease would prevent
the reading of the adjustment indicator unless the
chamber were wiped off.

After reviewing the comments, NHTSA has
decided not to adopt the detailed visibility pro-
posal because the requirement would raise signifi- |^
cant practicability problems. The agency notes
that the proposed eight-foot requirement would
necessitate extensive redesign of certain vehicle
configurations such as drop floor and moving
vans. In addition, the proposed visibility require-
ment would be impracticable for evaluating brake
adjusters that have been covered by road contami-
nants such as dirt, grime, and snow. NHTSA
believes that by not adopting the eight-foot view-
ing requirement, the standard will encourage
closer hands-on inspection of the equipment.
Based on the above considerations, the agency
has decided not to require that the adjustment
indicator be readable at a distance of eight feet.
The visibility provision now states that "the
condition of service brake under-adjustment shall
be provided by a brake adjustment indicator that
is discernible when viewed with 20/40 vision
from a location adjacent to or underneath the
vehicle."

d. Vehicle Type

The NPRM proposed that all air-braked
vehicles be equipped with an adjustment indica- ^
tor, regardless of brake system type. The NPRM
explained that there were three principal types of
air brake systems: S cam brakes which account
for 95 percent of the brake market; wedge type
brakes, three percent of the market; and disc
brakes, two percent of the market. While S cam
brakes have external adjustment mechanisms,
wedge brakes and some disc brakes have internal
mechanisms.

Several commenters, including Volvo GM
Heavy Truck, Navistar, GM, Bendix, Rockwell,
and MVMA, stated that adjustment indicators are
only practicable with external adjustment designs
such as S cam brakes with exposed pushrods.
MVMA stated that there was little if any need to
require adjustment indicators on internally
adjusted brakes. Like hydraulic brakes, air-brake
systems with internal adjustment designs would
have to be significantly redesigned to incorporate
an adjustment indicator. Rockwell believed that
the nominal benefits from having wedge brakes
and internally adjusted disc brakes equipped with
indicators did not warrant the significant costs ^
that would be needed to redesign these systems. ^

Bendix and Lear Siegler explained that some

PART 571; S121— PRE-234

external actuators are equipped with a protective
boot or a scraper seal.

After reviewing the comments and the available
information, NHTSA has determined that
although all air brakes should have a system of
automatic adjustment, it is not necessary to
require adjustment indicators on internally
adjusted brakes. The agency is not aware of any
significant adjustment problems with internally
adjusted brakes. In addition, such a requirement
for these designs would not be practicable given
the significant feasibility concerns and redesign
costs to require an adjustment indicator on
internally adjusted brake systems. The agency
notes that S cam brakes, except the approximately
one percent that have protective pushrod boots,
have exposed air chamber pushrods which easily
can be marked to indicate brake adjustment.

After a review of the comments to the docket
and other information on this issue, the agency
has decided not to require adjustment indicators
on service brake systems that have pushrod boots.
Systems having scraper seals and exposed
pushrods will be required to have adjustment
indicators, since the pushrods can be easily
marked and inspected. Brake actuators with
pushrod boots are made to provide performance
and reliability under severe operating conditions,
such as corrosive or hazardous material handling
and refuse collection and disposal. The heavy-
duty, durable adjustment indicators, adequately
integrated into the actuator system, that would be
necessary to withstand these severe operating
environments, would cost substantially more than
indicators on exposed pushrods. Brake systems
with pushrod boots account for perhaps one per-
cent of the brake actuator market, as previously
noted. These systems are being required to have

automatic brake adjusters. Further, many booted
systems are used with rolling diaphragm brake
chambers (roto chambers) that have longer strokes
than conventional chambers and thus provide a
greater operating range for automatic slack adjust-
ers and a longer period of use before the
underadjustment condition is reached. While the
agency is not requiring brake systems with booted
pushrods to have adjustment indicators, it would
revisit this issue if the number of these systems
increases substantially in the future. Thus, the
agency is only requiring externally adjusted
brakes with exposed pushrods to be equipped
with adjustment indicators. The agency estimates
that about 94 percent of air brakes will be
equipped with indicators.

3. Miscellaneous Concerns

Flxible commented that it should be allowed
the option of using manual slack adjusters during
its certification testing. NHTSA notes that Flxible
can do whatever it wants in its compliance test-
ing, if it can establish, should it become necessary
to do so, that use of its test procedure constitutes
due care. Nevertheless, NHTSA believes that
Flxible may have difficulty establishing due care
if it uses manual adjusters during its certification
testing, because an earlier rulemaking prohibited
the disconnecting of automatic adjusters during
agency compliance testing. (54 FR 40080.
September 28, 1989). That notice explained that
an important purpose behind the test conditions
and procedures is to test vehicles as they will per-
form when used on the road. Since automatic
brake adjusters are operational during normal use,
specifying that they be operational during agency
compliance testing helps approximate real-world

PART 571; S121— PRE-235

conditions and provides a better test of real-world
performance.

The ATA requested an exclusion from the
automatic adjuster requirements for vehicles
involved in "permit" operations such as
transporting hazardous waste and explosives.
While NHTSA has the authority to set standards
based on vehicle type, it does not typically have
the authority to set standards based on end use
(aside from school buses). Even if it had such
authority, vehicle manufacturers could not predict,
in many instances, which vehicles were ultimately
going to be used for permit operations and thus
could not identify which vehicles were excluded.
Many vehicles used in permit operations are
standard trucks and trailers with no special fea-
tures. If the agency were to attempt to exclude the
permit operation vehicles by excluding whole
vehicle types, the exclusion would be overbroad.
The agency notes that a variety of vehicle types
are used for these perniit operations, and if
NHTSA were to exclude all of these types, it
would be excluding many vehicles not used for
permit operations. In addition, the professed rea-
son to exclude vehicles in permit operations (i.e.,
the presumed frequency of manual brake adjust-
ments) can be accomplished with brakes equipped
with automatic adjusters. Some truckers involved
in dangerous activities adjust their brakes every
day instead of relying on their automatic adjust-
ers, because automatic adjusters are equipped with
external adjusting mechanisms similar to the man-
ual adjusters. Therefore, if a permit hauler desires
to adjust its brakes manually, it can do so. Based
on the above, the agency believes that heavy
haulers involved in permit operations should be
required to comply with the automatic adjustment
requirements.

International Transquip recommended a salt
spray test and a stroke cycle test for accuracy.

performance, and readability. NHTSA notes that
these tests were not proposed in the NPRM and
does not believe they are necessary at this time. jM
The agency believes that a safety need for these ~
additional requirements could not be established.
In addition, the existing SAE Recommended Prac-
tice on automatic adjusters already requires
environmental chamber tests along with cycle
testing. If additional information indicated that
these tests would provide significant safety bene-
fits at reasonable costs, the agency would con-
sider proposing them.

MGM Brakes commented that the SAE Truck
and Bus Brake Actuator Sub-Committee has writ-
ten and approved a recommended practice for
cam or disc brake actuators. However, the SAE
has withheld this document from publication
because its policy is to not publish any rec-
ommended practice that will require another
manufacturer to infringe a patent. Apparently, one
air brake actuator manufacturer was recently
issued a patent on a stroke indicator marking sys-
tem. Notwithstanding the SAE's concern about
patent infringement, NHTSA notes that this rule
specifies a general performance standard. There-
fore, the agency does not anticipate that restric- ^
tions caused by patents will be a problem because ^
there are many different indicator designs and air
chamber pushrods may be marked in many ways.

Hycliaiilically-Braked Systems
1 . Brake Adjusters

The NPRM discussed the need for automatic
brake adjusters on hydraulically-braked vehicles,
including passenger cars. The notice explained
that all new passenger cars have been manufac-
tured with automatic adjusters for several years.
The agency stated that such a requirement would
be consistent with the agency's proposal in Stand-
ard No. 135 about international brake harmoni-
zation (52 PR 1474, January 14, 1987. 56 PR
30528, July 3, 1991). The proposal requested
comments on whether passenger cars should be
covered by this amendment to Standard No. 105.
The proposal also requested comment about
whether other hydraulically-braked vehicles
should be required to have automatic brake
adjusters.

No commenter expressly supported equipping ^
passenger cars and other hydraulic braked ^
vehicles with automatic brake adjusters. However,

PART 571: S121— PRE-236

several commenters, including General Motors
and the Motor Vehicle Manufacturers Association
(MVMA), implicitly supported this requirement
by commenting that an immediate effective date
for such vehicles was feasible, provided that the
requirements did not require the development of
new designs. Chrysler and Toyota questioned the
need for such a requirement, claiming that
hydraulically-braked vehicles are already
equipped with such devices.

In addition. Ford and GM commented that, in
the interests of international brake harmonization,
the requirements about brake adjusters in Stand-
ard No. 105 and 135 should be identical. This
consideration led Ford to state that the proposal
in Standard No. 105 about automatic correction
for over-adjustment was not needed.

After reviewing these comments, NHTSA has
determined that Standard No. 105 should be
amended to require automatic brake adjusters.
Because vehicles subject to Standard No. 105
typically are equipped with these devices, the
agency does not anticipate that the requirement
would pose a burden on manufacturers. In addi-
tion, amending Standard No. 105 to require these
devices will result in consistency between that
Standard and Standard No. 135. The agency notes
that such consistency is important because under
the Standard No. 135 proposal, a manufacturer
could comply with either standard during the five-
year phase-in period for Standard No. 135.

2. Adjustment Indicators

NHTSA continues to believe that there is no
significant safety problem with automatic adjust-
ers for hydraulically-braked vehicles or with
checking the adjustment of such vehicles. Accord-
ingly, the agency has decided not to require
adjustment indicators on hydraulically-braked
vehicles.

Ejfective Date

The NPRM proposed that the amendments
become effective two years after promulgation of
the final rule. The agency proposed the same
leadtime for both air-braked and hydraulically-
braked vehicles.

PART 571; S121— PRE-237

sider providing longer leadtime for vehicles or
brake systems which needed additional leadtime.

Thirteen commenters addressed the proposed
leadtime for requiring brake adjusters and adjust-
ment indicators on air-braked vehicles. The Inter-
national Brotherhood of Teamsters and a brake
consultant believed that a leadtime of one year or
less was appropriate, claiming that the equipment
is already available. Haldex stated that a one year
lead time would be possible provided that the
issue of adjustment indicators was separated. Sev-
eral commenters, including Ford, the National
School Transportation Association (NSTA), the
American Petroleum Institute, the Owner-Operator
Independent Drivers Association, TTMA, GM,
and MVMA believed that the proposed two year
leadtime was appropriate for requirements similar
to those being adopted in this final rule. Chrysler
believed that leadtime of three years would be
necessary for some manufacturers to develop
automatic adjusters and indicators.

Based on the comments and available informa-
tion, NHTSA has determined that a one year lead-

time is appropriate for requiring automatic adjust-
ers on hydraulically-braked vehicles. Those com-
menters that addressed the issue indicated that an ^m
immediate effective date would be acceptable. No ™
commenter stated that an effective date longer
than one year was necessary or that a one year
leadtime would pose an unreasonable burden.
Based on its review of hydraulically-braked
vehicles, NHTSA believes that all such passenger
cars and light trucks are equipped with an auto-
matic adjuster. As for hydraulically-braked
medium and heavy duty vehicles, the agency
notes that these vehicles are typically manufac-
tured by specialty manufacturers that purchase the
axle sets and brake components from major
manufacturers. The agency believes that the major
manufacturers or trade groups representing the
specialty manufacturers would have expressed
their concern if a shorter leadtime had posed a
hardship.

This final rule does not have any retroactive
effect. Under section 103(d) of the National Traf-
fic and Motor Vehicle Safety Act (15 U.S.C.
1392(d)), whenever a Federal motor vehicle safety
standard is in effect, a state may not adopt or
maintain a safety standard applicable to the same ^
aspect of performance which is not identical to
the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending or
revoking Federal motor vehicle safety standards.
That section does not require submission of a
petition for reconsideration or other administrative
proceedings before parties may file suit in court.

PART 571— [AMENDED]

In consideration of the foregoing, 49 CFR Part
571 is amended as follows:

1. The authority citation for Part 571 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403, 1407:
delegation of authority at 49 CFR 1.50.

§571.105 [Amended]

2. S5.1 of §571.105 is amended by adding the
following after the current heading:

Each vehicle shall be equipped with a service ^
brake system acting on all wheels. Wear of the

PART 571; S121— PRE-238

service brake shall be compensated for by means
of a system of automatic adjustment.

§571.121 [Amended]

3. S5.1.8 of 571.121 is revised to read as fol-
lows:

S5.1.8 Brake distribution and automatic adjust-
ment. Each vehicle shall be equipped with a serv-
ice brake system acting on all wheels.

(a) Brake adjuster. Wear of the service
brakes shall be compensated for by means of a
system of automatic adjustment. The readjustment
limits shall be in accordance with those specified
in Appendix G to Subchapter B of Chapter III —
"Minimum Periodic Inspection Standards," 49
CFR Parts 200 to 399.

4. S5.2.2 of §571.121 is revised to read as fol-
lows:

S5.2.2 Brake distribution and automatic adjust-
ment. Each vehicle shall be equipped with a serv-
ice brake system acting on all wheels.

(a) Brake Adjuster. Wear of the service
brakes shall be compensated for by means of a
system of automatic adjustment. The readjustment
limits shall be in accordance with those specified
in Appendix G to Subchapter B of Chapter III —
■'Minimum Periodic Inspection Standards," 49
CFR Parts 200 to 399.

Issued on October 14, 1992.

Marion C. Blakey
Administrator

57 F.R. 47793
October 20, 1992

PART 571; S121— PRE-239

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 sys-
tems 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 sys-
tems. However, it does not apply to —

(a) Any trailer that has a width of more than
102.36 inches with extendable equipment in the
fully retracted position and is equipped with two
short track axles in a line across the width of the
trailer.

(b) Any vehicle equipped with an axle that has
) a GAWR of 29,000 pounds or more;

(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 occupants
other than the driver and operating crew;

(e) Any trailer that has a 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.
Notwithstanding any language to the contrary,

sections S5.3.1, S5.3.1.1, S5.3.2, S5.3.2.1,
S5.3.2.2, S5.7.1, S5.7.3(a) and S5.7.3(b) of this
standard are not applicable to trucks and trailers,
and section S5.3.1 of this standard is not
applicable to buses.

L S4. Definitions.

Agricultural commodity trailer means a trailer
that is designed to transport bulk agricultural

commodities in off-road harvesting sites and to a
processing plant or storage location, as evidenced
by skeletal construction that accommodates har-
vest containers, a maximum length of 28 feet, and
an arrangement of air control lines and reservoirs
that minimizes damage in field operations.

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 compressed
air or vacuum only to assist the driver in applying
muscular force to hydraulic or mechanical compo-
nents.

Antilock system means a portion of a service
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 transport
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.

Container chassis trailer means a semitrailer of
skeleton contruction limited to a bottom frame,
one or more axles, specially built and fitted with
locking devices for the transport of intermodal
shipping containers, so that when the chassis and
container are assembled, the units serve the same
function as an over the road trailer.

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 condi-
tion, 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
S393.106of this title.

Initial brake temperature means the average
temperature of the service brakes on the hottest

PART 571; S121-1

(Rev. 8/15/88)

axle of the vehicle 0.2 miles before any brake
application.

Intermodal shipping container means a
reusable, transportable enclosure that is expecially
designed with integral locking devices for secur-
ing the container to the trailer to facilitate the
efficient and bulk shipping and transfer of goods
by, or between various modes of transport, such
as highway, rail, sea and air.

Load divider dolly means a composed of a
trailer chassis and one or more axles, with no
solid bed, body,or container attached, and which
is designed exclusively to support a portion of the
load on a trailer or truck excluded from all the
requirements of this standard.

Pulpwood trailer means a trailer that is
designed exclusively for harvesting logs or pulp-
wood 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 offroads operations.

Skid number means the frictional resistance of
a pavement measured in accordance with Amer-
ican Society for Testing and Materials Method
"E-274-70 (as revised July 1974)" at 40 mph,
omitting water delivery as specified in paragraphs
S7.1 and 7.2 of that method.

Straddle trailer means a trailer that is designed
to transport bulk agricultural commodities from
the harvesting location as evidenced by a frame-
work that is driven over the cargo and lifting
arms that suspend the cargo for transit.

S5. Requirements. Each vehicle shall meet the
following requirements under the conditions speci-
fied in S6.

S5.1 Required equipment— truclts and buses.

Each truck and bus shall have the following equip-
ment:

S5.1.1 Air Compressor. An air compressor of
sufficient capacity to increase air pressure in the
supply and service reservoirs from 85 pounds per
square inch (p.s.i.) to 100 (p.s.i.) 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

[5.1.1.1 Air compressor cut-in pressure.

Effective October 8, 1992, or at the manufactur- ^
er's option effective November 7, 1991, the air ^|
compressor governor cut-in pressure shall be
greater than 85 p.s.i. (56 F.R. 50666— October 8.
1991. Effective: October 8, 1992. Optional compli-
ance: November 7, 1991.)]

55.1.2 Reservoirs. One or more service res-
ervoir systems, from which air is delivered to the
brake chambers, and either an automatic conden-
sate drain valve for each service reservoir or a
supply reservoir between the service reservoir sys-
tem and the source of air pressure.

55.1.2.1 The combined volume of all service res-
ervoirs 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. However, the reservoirs on the
truck portion of an auto transporter need not meet
this requirement.

55.1.2.2 Each reservoir shall be capable of with-
standing an internal hydrostatic pressure of five M
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 res-
ervoir and the source of air pressure, by check
valves or equivalent devices whose proper func-
tioning can be checked without disconnecting any
air line or fitting.

55. 1.2.4 Each reservoir shall have condensate
drain valve that can be manually operated.

55.1.3 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 per-

son seated in the normal driving position, that ^
indicates the service reservoir system air pressure. ^
The accuracy of the gauge shall be within plus or

PART 571; S121-2

minus 7 percent of the compressor cut-out pres-
sure.

S5.2 Required equipment-trailers. Each trailer
shall have the following equipment:

55.1.5 Warning signal. A signal, other than a
pressure gauge, that gives a continuous warning 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 system is
below 60 p.s.i. 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 nor-
mal 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 continuously visible. The
signal shall operate in the specified manner each
time the ignition is returned to the "on" or "run"
position.

' S5.1.7 Service brake stop lamp switch. A

switch that lights the stop lamps when the service
brake control is statically depressed to a point that
produces a pressure of 6 p.s.i. or less in the serv-
ice brake chambers.

S5.1.8 [Brake distribution and automatic
adjustment. Each vehicle shall be equipped with
a service brake system acting on all wheels.

(a) Brake adjuster. Wear of the service brakes
shall be compensated for by means of a system
of automatic adjustment. The readjustment limits
shall be in accordance with those specified in
Appendix G to Subchapter B of Chapter III-
"Minimum Periodic Inspection Standards," 49
CFR Parts 200 to 399.

y adjacent to or underneath the vehicle. (57 F.R.
47793— October 20, 1992. Effective: October 20,
1993.)]

55.2.1 Reservoirs. One or more reservoirs to
which the air is delivered from the towing vehicle.

55.2.1.1 For vehicles manufactured before Octo-
ber 8, 1992, total service reservoir volume shall be
at least eight times the combined volume of all
service brake chambers at maximum travel of the
pistons or diaphragms. For vehicles manufactured
on or after October 8, 1992, or at the manufactur-
er's option for vehicles manufactured on or after
November 7. 1991, the total volume of each serv-
ice reservoir shall be at least eight times the com-
bined volume of all service brake chambers serv-
iced by that reservoir at the maximum travel of
the pistons or diaphragms of those service brake
chambers. However, the reservoirs on a heavy
hauler trailer and on the trailer portion of an auto
transporter need not meet the requirements speci-
fied in S5.2.1.1.

55.2.1.2 Each reservoir shall be capable of with-
standing an internal hydrostatic pressure of 500
p.s.i. for 10 minutes.

55.2.1.3 Each reservoir shall have a condensate
drain valve that can be manually operated.

55.2.1.4 Each service reservoir shall be protected
against loss of air pressure due to failure or leak-
age in the system between the service reservoir
and its source of air pressure by check valves or
equivalent devices.

55.2.1.5 For vehicles manufactured before Octo-
ber 8, 1992, a reservoir shall be provided that is
capable, when pressurized to 90 p.s.i., of releasing
the vehicle's parking brakes at least once and that
is unaffected by a loss of air pressure in the serv-
ice brake system. This requirement need not be
met if the vehicle meets the applicable require-
ments specified in S5. 1.1.1, the second sentence of
S5.2.1.1, and S5.8.1 through S5.8.4, notwithstand-
ing the effective date of those requirements.

55.2.2 [Brake distribution and automatic
adjustment. Each vehicle shall be equipped with
a service brake system acting on all wheels.

PART 571: S121-3

(Rev. 10/20/92)

(a) Brake adjuster. Wear of the service brakes
shall be compensated for by means of a system
of automatic adjustment. The readjustment limits
shall be in accordance with those specified in
Appendix G to Subchapter B of Chapter III-
" Minimum Periodic Inspection Standards," 49
CFR Parts 200 to 399.

(b) Brake indicator. For each brake equipped
with an external automatic adjustment mechanism
and having an exposed pushrod, the condition of
service brake under-adjustment shall be displayed
by a brake adjustment indicator in a manner that
is descemible when viewed with 20/40 vision
from a location adjacent to or underneath the
vehicle. (57 F.R. 47793— October 20, 1992. Effec-
tive: October 20, 1993.)]

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 speci-
fied in this standard. However, a heavy hauler
trailer and the truck and trailer portions of an auto
transporter need not meet the requirements of
S5.3.

S5.3.1 Stopping distance — trucks and buses.

When stopped six times for each combination of
weight, speed, and road condition 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 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 trailer 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
of 81.

(b) 60 mph service brake stops on skid number
of 81.

(d) 20 mph emergency brake stops on skid
number of 8 1 .

(e) 60 mph emergency brake stops on skid
number of 8 1 .

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 ^
of81. 4

(b) 60 mph service brake stops on skid number
range 81.

(d) 20 mph emergency brake stops on skid
number range 8 1 .

(e) 60 mph emergency brake stops on skid
number range 8 1 .

7. Parking brake test with vehicle at unloaded
weight plus 500 lb.

S5.3.1.1 Stop the vehicle from 60 mph and 20
mph on a surface with a skid number of 81, and
from 20 mph on a wet surface with a skid number
of 30, with the vehicle (a) loaded to its gross
vehicle weight rating, and (b) at its unloaded
vehicle weight plus 500 pounds (including driver
and instrumentation). If the speed attainable in 2
miles is less than 60 mph, the vehicle shall stop
from a speed in Table II that is 4 to 8 mph less
than the speed attainable in 2 miles.

(Rev. 10/20/92)

PART 571: S121-4

Table II. — Stopping Distance in Feet

Service Brake stopping distance

Emergency

Brake

stopping

distance

Vehicle speed in miles per

Column

I Skid No. 81 Column 2 Skid No. 30

Skid No.

hour

Column 3

Column 4

35 60

123

131

170

186

101

225

250

131

325

165

358

409

203

435

504

246

520

608

293

613

720

55.3.2 Stopping capability — trailers. When
tested at each combination of weight, speed, and
road condition specified in S5.3.2.1, in the
sequence specified in Table I, with air pressure of
90 p.s.i. 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 without
lockup of any wheel at speeds above 10 mph,
except for —

(a) Controlled lockup of wheels allowed by an
antilock system; or

(b) Lockup of wheels on nonsteerable axles
other than the two reannost 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 sys-
tem.

55.3.2.1 Stop the vehicle from 60 mph and 20
mph on a surface with skid number of 81, and
from 20 mph on a wet surface with a skid number
30, with the vehicle (a) loaded to its gross vehicle
weight rating, and (b) at its unloaded vehicle
weight plus 500 pounds (including instrumenta-
tion).

55.3.2.2 When stopped in accordance with S5.3.2,
a pulpwood trailer need not meet the requirements
relating to wheel lockup, but must nevertheless
meet the requirements of staying within the 12-
foot lane.

55.3.3 Brake actuation time. Each service brake
system shall meet the requirements of S5.3.3.1,
except that, at the option of the manufacturer,
vehicles manufactured before May 3, 1991 may

meet the requirements specified in either S5.3.3.2
or S5.3.3.3

55.3.3.1 (a) With an initial service reservoir sys-
tem air pressure of 100 p.s.i., the air pressure in
each brake chamber shall, when measured from
the first movement of the service brake control,
reach 60 p.s.i. in not more than 0.45 seconds in
the case of trucks and buses, 0.50 seconds in the
case of trailers, other than trailer converter dollies,
designed to tow another vehicle equipped with air
brakes, 0.55 seconds in the case of trailer con-
verter dollies, and 0.60 seconds in the case of
trailers other than trailers designed to tow another
vehicle equipped with air brakes shall meet the
above actuation time requirement with a 50-cubic-
inch test reservoir connected to the control line
output coupling. A trailer, including a trailer con-
verter dolly, shall meet the above actuation time
requirement with its control line input coupling
connected to the test rig shown in Figure 1 .

(b) For a vehicle that is manufactured after
May 3, 1991 and is designed to tow another
vehicle equipped with air brakes, the pressure in
the 50-cubic-inch test reservoir referred to in
S5.3.3.1(a) shall, when measured from the first
movement of the service brake control, reach 60
p.s.i. not later than the time the fastest brake
chamber on the vehicle reaches 60 p.s.i. or, at the
option of the manufacturer, in not more than 0.35
seconds in the case of trucks and buses, 0.55 sec-
onds in the case of trailer converter dollies, and
0.50 seconds in the case of trailers other than
trailer converter dollies.

55.3.3.2 Optional requirement for vehicles
manufactured before May 3, 1991. With an ini-
tial service reservoir system air pressure of 100
p.s.i., the air pressure in each brake chamber shall,
when measured from the first movement of the

PART 571; SI 21-5

service brake control, reach 60 p.s.i. in not more
tiian 0.45 seconds in the case of trucks and buses,
and 0.60 seconds in the case of trailers. A vehicle
designed to tow another vehicle equipped with air
brakes shall meet the above actuation time
requirement with a 50-cubic-inch test reservoir
connected to the control line output coupling. A
trailer, including a trailer converter dolly, shall
meet the above actuation time requirement with its
control line input coupling connected to the test
rig shown in Figure 1.

S5.3.3.3 Optional requirement for vehicles
manufactured before May 3, 1991. With an ini-
tial service reservoir system air pressure of 100
p.s.i., the air pressure in each brake chamber shall,
when measured from the first movement of the
service brake control, reach 60 p.s.i. 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 another vehicle equipped with air brakes
shall meet the above actuation-time requirement
with a 50-cubic-inch test reservoir connected to
the control line output coupling. A trailer, includ-
ing a trailer converter dolly, shall meet the above
actuation time requirement with its control line
input coupling connected to the test rig shown in
Figure 1(a).

S5.3.4 Brake release time. Each service brake
system shall meet the requirements of S5.3.4.1,
except that, at the option of the manufacturer,
vehicles manufactured before May 3, 1991 may
meet the requirements specified in either S5. 3.4.2
or S5.3.4.3.

S5.3.4.1 (a) With an initial sei-vice brake chamber
air pressure of 95 p.s.i., the air pressure in each
brake chamber shall, when measured from the first
movement of the service brake control, fall to 5
p.s.i. in not more than 0.55 seconds in the case of
trucks and buses, and fall to 5 p.s.i. in not more
than 0.55 seconds in the case of trucks and buses,
1.00 seconds in the case of trailers, other than
trailer converter dollies, designed to tow another
vehicle equipped with air brakes, 1.10 seconds in
the case of the trailer converter dollies, and 1.20
seconds in the case of trailers other the trailers
designed to tow another vehicle equipped with air
brakes. A vehicle designed to tow another vehicle
equipped with air brakes shall be capable of meet-

ing the above release time requirement with a 50-
cubic-inch test reservoir connected to the control
line coupling. A trailer, including a trailer con- ^
verter dolly, shall meet the above release time
requirements with its brake system connected to
the test rig shown in Figure 1 .

(b) For vehicles designed to tow another
vehicle equipped with air brakes, effective May 3,
1991, the pressure in the 50-cubic-inch test res-
ervoir referred to in S5.3.4.1(a) shall, when meas-
ured from the first movement of the service brake
control, fall to 5 p.s.i. in not more than 0.75 sec-
onds in the case of trucks and buses, 1.10 seconds
in the case of trailer converter dollies, and 1.00
seconds in the case of trailers other than trailer
converter dollies.

[S5.3.4.2 Optional requirement for vehicles
manufactured before May 3, 1991. With an ini-
tial service brake chamber air pressure of 95 p.s.i.,
the air pressure in each brake chamber shall, when
measured from the first movement of the service
brake control, fall to 5 p.s.i. in not more than 0.55
seconds in the case of trucks and buses, and 1.20
seconds in the case of trailers. A vehicle designed
to tow another vehicle equipped with air brakes m
shall meet the above release time requirement with
a 50-cubic-inch test reservoir connected to the
control line output coupling. A trailer, including a
trailer converter dolly, shall meet the above
release time requirement with its control line input
coupling connected to the test rig shown in Fig-
ure 1.

[S5.3.4.3 Optional requirement for vehicles
manufactured before May 3, 1991. With an ini-
tial service brake chamber air pressure of 95 p.s.i.,
the air pressure in each brake chamber shall, when
measured from the first movement of the service
brake control, fall to 5 p.s.i. in not more than 0.55
seconds in the case of trucks and buses, and 0.65
seconds in the case of trailers. A vehicle designed
to tow another vehicle equipped with air brakes
shall meet the above release time requirement with
a 50-cubic-inch test reservoir connected to the
control line output coupling. A trailer, including a
trailer converter dolly, shall meet the above
release time requirement with its control line input
coupling connected to the test rig shown in Figure d

1(a). (54 F.R. 18890— May 3, 1989. Effective: June
2, 1989.)]

PART 571; S121-6

[S5.3.5 Control signal pressure differential-
converter dollies and trailers designed to tow
another vehicle equipped with air brakes.

(a) For a trailer manufactured on or after
August 23, 1993 and designed to tow another
vehicle equipped with air brakes, the pressure dif-
ferential between the control line input coupling
and a 50 cubic inch test reservoir attached to the
control line output coupling shall not exceed the
values specified in S5. 3. 5(a)(1) through (4) —

(1) 1 p.s.i. at all input pressures equal to or
greater than 5 p.s.i., but not greater than 20 p.s.i.;
and

(2) 2 p.s.i. at all input pressures greater than
20 p.s.i.

(b) The requirements in S5.3.5(a) shall be
met —

(1) When the pressure at the imput coupling
is steady, increasing or decreasing;

(2) When air is applied to or released from
the control line input coupling using the trailer
test rig shown in Figure 1;

(4) Operating the trailer test rig in the same
manner and under the same conditions as it is
operated during testing to measure brake actuation
and release times, as specified in S5.3.3 and
S5.3.4, except for the installation of the orifice in
the control line to restrict airflow rate. (57 F.R.
37902— August 21, 1992. Effective: August 23,
1992.) Vehicles manufactured before the effective
date may comply with the rule's amendments.
Effective September 21, 1992.]

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
adjustments other than those specified in the
standard. 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.
However, a brake assembly on a heavy hauler
trailer manufactured before July 1, 1979, need not
meet the requirements of this section.

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

relative to brake chamber air pressure shall have
values not less than those shown in Column 1 of
Table III. Retardation force shall be determined as
follows —

Table III. — Brake Retardation Force

BRAKE RETARDATION BRAKE CHAMBER PRES-

FORCE GAWR Column 1 SURE, p.s.i. Column 2

0.05
0.12
0.18
0.25
0.31
0.37
0.41

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 p.s.i. 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 retardation
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 between 125°F
and 200°F.

S5.4.2 Brake power. When mounted on an iner-
tia 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
decelerating to a stop from 20 mph at an average
deceleration rate of 14 fpsps one minute after the
10th acceleration. 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

PART 571; S121-7

speed equivalent to 50 mph, apply the brake and
decelerate at an average deceleration rate of 9
fpsps to 15 mph. Upon reaching 15 mph, acceler-
ate to 50 mph and apply the brake for a second
time 72 seconds after the start of the first applica-
tion. Repeat the cycle until 10 decelerations have
been made. The service line air pressure shall not
exceed 100 p.s.i. 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, decel-
erate to a stop at an average deceleration rate of
14 fpsps.

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 making 20
consecutive stops from 30 mph at an average
deceleration rate of 12 fpsps, 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 fpsps shall be not more than 85
Ib./in.-, 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.

S5.5 Antilock system.

meets the requirements of S5.6.1 or S5.6.2, at the
manufacturer's option, and the requirements of
S5.6.3 and S5.6.4. S5.6.5, and S5.6.6. However,
the trailer portion of any agricultural commodity
trailer, heavy-hauler trailer, or pulpwood trailer
shall meet the requirements of this section or, at
the option of the manufacturer, the requirements
of § 393.43 of this title.

S5.6.1 Static retardation force. With all other
brakes rendered inoperative, during a static draw-
bar pull in a forward or rearward direction, the
static retardation force produced by the application
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

GVWR

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.

55.5.1 Antilock system failure. On a vehicle
equipped with an antilock system, electrical failure
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 (including a trailer converter dolly)
equipped with an antilock system that requires
electrical power for operation, the power shall be
obtained from either the stop lamp circuit or one
or more separate electrical circuit or circuits
specifically provided to power the trailer antilock
system. The antilock system shall automatically
receive power from the stop lamp circuit, if the
separate power circuit or circuits are not in use.
(57 F.R. 30911— July 13, 1992. Effective: August 12,
1992.)]

S5.6 Parking brake system. Each vehicle other
than a trailer converter dolly shall have a parking
brake system that under the conditions of S6.1

55.6.2 Grade holding. With all parking brakes
applied, the vehicle shall remain stationary facing
uphill and facing downhill on a smooth, dry port-
land cement concrete roadway with a 20% grade,
both (a) when loaded to its gross vehicle weight
rating, and (b) at its unloaded vehicle weight plus
500 pounds (including driver and instrumentation).

55.6.3 Application and holding. Each parking
brake system shall meet the requirements of
S5.6.3.1 through S5.6.3.4, except that, at the
option of the manufacturer, the parking brake sys-
tem in each vehicle manufactured before Decem-
ber 9, 1991, may meet either those requirements
specified in S5.6.3.5.

S5.6.3.1 The parking brake system shall be
capable of achieving the minimum performance
specified either in S5.6.1 or S5.6.2 with any single
leakage-type failure, in any other brake system, of
a part designed to contain compressed air or brake
fluid (except failure of a component of a brake

(Rev. 7/13/92)

PART 571; S121-8

chamber housing, [but including failure of any
brake chamber diaphragm that is part of any other
\ brake system including a diaphragm which is
common to the parking brake system and any
other brake system), when the pressures in the
vehicle's parking brake chambers are at the levels
determined in S5.6.3.4. (56 F.R. 26927— June 12,
1991. Effective: December 9, 1991.)]

55.6.3.2 [A mechanical means shall be provided
that, after a parking brake application is made
with the pressures in the vehicle's parking brake
chambers at the levels determined in S5.6.3.4, and
all air and fluid pressures in the vehicle's braking
systems are then bled down to zero, and without
using electrical power, holds the parking brake
application with sufficient parking retardation
force to meet the minimum performance specified
in S5.6.3.1 and in either S5.6.1 or S5.6.2. (56 F.R.
26927— June 12, 1991. Effective: December 9,
1991.)]

55.6.3.3 [For trucks and buses, with an initial res-
ervoir system pressure of 100 p.s.i. and, if
designed to tow a vehicle equipped with air
brakes, with a 50-cubic-inch test reservoir con-

y nected to the supply line coupling, no later than
three seconds from the time of actuation of the
parking brake control, the mechanical means
referred to in S5.6.3.2 shall be actuated. For trail-
ers, with the supply line initially pressurized to
100 p.s.i. using the supply line portion of the
trailer test rig (Figure 1) and, if designed to tow
a vehicle equipped with air brakes, with a 50-
cubic-inch test reservoir connected to the rear sup-
ply line coupling, no later than three seconds from
the time venting to the atmosphere of the front
supply line coupling is initiated, the mechanical
means referred to in S5.6.3.2 shall be acUiated.
This requirement shall be met for trucks, buses
and trailers both with and without any single leak-
age-type failure, in any other brake system, of a
part designed to contain compressed air or brake
fluid (excluding failure of a component of a brake
chamber housing but including failure of any
brake chamber diaphragm that is part of any other
brake system including a diaphragm which is
common to the parking brake system and any
other brake system). (56 F.R. 26927— June 12,
1991. Effective: December 9, 1991.)]

55.6.3.4 [The parking brake chamber pressures
for S5.6.3.1 and S5.6.3.2 are determined as fol-

lows. For trucks and buses, with an initial res-
ervoir system pressure of 100 p.s.i. and, if
designed to tow a vehicle equipped with air
brakes, with a 50-cubic-inch test reservoir con-
nected to the supply line coupling, any single
leakage-type failure, in any other brake system, of
a part designed to contain compressed air of brake
fluid (excluding failure of a component of a brake
chamber housing but including failure of any
brake chamber diaphragm that is part of any other
brake system including a diaphragm which is
common to the parking brake system and any
other brake system), is introduced in the brake
system. The parking brake control is actuated and
the pressures in the vehicle's parking brake cham-
bers are measured three seconds after that actu-
ation is initiated. For trailers, with the supply line
initially pressurized to 100 p.s.i. using the supply
line portion of the trailer test rig (Figure 1) and,
if designed to tow a vehicle equipped with air
brakes, with a 50-cubic-inch test reservoir con-
nected to the rear supply line coupling, any single
leakage-type failure, in any other brake system, of
a part designed to contain compressed air or brake
fluid (excluding failure of a component of a brake
chamber housing but including failure of any
brake chamber diaphragm that is part of any other
brake system including a diaphragm which is
common to the parking brake system and any
other brake system), is introduced in the brake
system. The front supply line coupling is vented
to the atmosphere and the pressures in the
vehicle's parking brake chambers are measured
three seconds after that venting is initiated. (56
F.R. 26927— June 12, 1991. Effective: December 9,
1991.)]

S5.6.3.5. Optional requirement for vehicles
manufactured before [December 9, 1991]. The

parking brake system shall be capable of achiev-
ing the minimum performance specified either in
S5.6.1 or S5.6.2. with any single leakage-type fail-
ure, in any other brake system, of a part designed
to contain compressed air or brake fluid (except
failure of a component of a brake chamber hous-
ing [but including failure of any brake chamber
diaphragm that is part of any other brake system
including a diaphragm which is common to the
parking brake system and any other brake sys-
tem).] Once applied, the parking brakes shall be
held in the applied position solely by mechanical
means. (56 F.R. 26927— June 12, 1991. Effective:
December 9, 1991.)

PART 571: S121-9

(Rev. 6/12/91)

S5.6.4 — Parking brake control — trucks and
buses. The parking brake control shall be sepa-
rate from the service brake control. It shall be
operable by a person seated in the normal driving
position. The control shall be identified in a man-
ner that specifies the method of control operation.
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.

[S5.6.5 Release performance. Effective
December 9, 1991, each parking brake system
shall meet the requirements specified in S5.6.5.1
through S5.6.5.4.

[S5.6.5.1 For trucks and buses, with initial condi-
tions as specified in S5.6.5.1, at all times after an
application actuation of the parking brake control,
and with any subsequent level of pressure, or
combination of levels of pressure, in the reservoirs
of any of the vehicle's brake systems, no reduc-
tion in parking brake retardation force shall result
from a release actuation of the parking brake con-
trol unless the parking brakes are capable, after
such release, of being reapplied at a level meeting
the minimum performance specified either in
S5.6.1 or S5.6.2. This requirement shall be met
both with and without the engine on, and with and
without any single leakage-type failure, in any
other brake system, of a part designed to contain
compressed air or brake fluid (excluding failure of
a component of a brake chamber housing but
including failure of any brake chamber diaphragm
that is part of any other brake system including a
diaphragm which is common to the parking brake
system and any other brake system).

[S5.6.5.2 The initial conditions for S5.6.5.1 are as
follows. The reservoir system pressure is 100 p.s.i.
If the vehicle is designed to tow a vehicle
equipped with air brakes, a 50-cubic-inch test res-
ervoir is connected to the supply line coupling.

[S5.6.5.3 For trailers, with initial conditions as
specified in S5. 6.5.4, at all times after actuation of
the parking brakes by venting the front supply line
coupling to the atmosphere, and with any subse-
quent level of pressure, or combination of levels
of pressure, in the reservoirs of any of the
vehicle's brake systems, the parking brakes shall
not be releasable by repressurizing the supply line
using the supply line portion of the trailer test rig
(Figure 1) to any pressure above 70 p.s.i., unless

the parking brakes are capable, after such release,
of reapplication by subsequent venting of the front
supply line coupling to the atmosphere, at a level ^
meeting the minimum performance specified ^
either in S5.6.1 or S5.6.2. This requirement shall
be met both with and without any single leakage-
type failure, in any other brake system, of a part
designed to contain compressed air or brake fluid
(excluding failure of a component of a brake
chamber housing but including failure of any
brake chamber diaphragm that is part of any other
brake system including a diaphragm which is
common to the parking brake system and any
other brake system).

[S5.6.5.4 The initial conditions for S5.6.5.3 are as
follows. The reservoir system and supply line are
pressurized to 100 p.s.i., using the supply line por-
tion of the trailer test rig (Figure 1 ). If the vehicle
is designed to tow a vehicle equipped with air
brakes, a 50-cubic-inch test reservoir is connected
to the rear supply line coupling. (56 F.R. 26927 —
June 12, 1991. Effective: December 9, 1991.)]

[S5.6.6 Accumulation of actuation energy.

Effective December 9, 1991, each parking brake
system shall meet the requirements specified in M
S5.6.6.1 through S5.6.6.6. ^

[S5.6.6.1 For trucks and buses, with initial condi-
tions as specified in S5.6.6.2, the parking brake
system shall be capable of meeting the minimum
performance specified either in S5.6. 1 or S5.6.2,
with any single leakage-type failure, in any other
brake system, of a part designed to contain com-
pressed air or brake fluid (excluding failure of a
component of a brake chamber housing but
including failure of any brake chamber diaphragm
that is part of any other brake system including a
diaphragm which is common to the parking brake
system and any other brake system), at the conclu-
sion of the test sequence specified in S5.6.6.3.

[S5.6.6.2 The initial conditions for S5.6.6.1 are as
follows. The engine is on. The reservoir system
pressure is 100 p.s.i. If the vehicle is designed to
tow a vehicle equipped with air brakes, a 50-
cubic-inch test reservoir is connected to the supply
line coupling.

[S5.6.6.3 The test sequence for S5.6.6.1 is as fol- J
lows. The engine is turned off. Any single leakage "
type failure, in any other brake system, of a part

(Rev. 6/12/91)

PART 571; S121-10

designed to contain compressed air or brake fluid
(excluding failure of a component of a brake
\ chamber housing but including failure of any
brake chamber diaphragm that is part of any other
brake system including a diaphragm which is
common to the parking brake system and any
other brake system), is then introduced in the
brake system. An application actuation of the
parking brake control is then made. Thirty seconds
after such actuation, a release actuation of the
parking brake control is made. Thirty seconds
after the release actuation, a final application actu-
ation of the parking brake control is made.

[S5.6.6.4 For trailers, with initial conditions as
specified in S5. 6.6.5, the parking brake system
shall be capable of meeting the minimum perform-
ance specified either in S5.6.1 or S5.6.2, with any
single leakage-type failure, in any other brake sys-
tem, of a part designed to contain compressed air
or brake fluid (excluding failure of any brake
chamber diaphragm that is part of any other brake
system including a diaphragm which is common
to the parking brake system and any other brake
system), at the conclusion of the test sequence
specified in S5.6.6.6.

[S5.6.6.5 The initial conditions for S5. 6.6.4 are as
follows. The reservoir system and supply line are
pressurized to 100 p.s.i., using the supply line por-
tion of the trailer test rig (Figure 1). If the vehicle
is designed to tow a vehicle equipped with air
brakes, a 50-cubic-inch test reservoir is connected
to the rear supply line coupling.

[S5.6.6.6 The test sequence for S5. 6.6.4 is as fol-
lows. Any single leakage type failure, in any other
brake system, of a part designed to contain com-
pressed air or brake fluid (excluding failure of a
component of a brake chamber housing but
including failure of any brake chamber diaphragm
that is part of any other brake system including a
diaphragm which is common to the parking sys-
tem and any other brake system), is introduced in
the brake system. The front supply line coupling
is vented to the atmosphere. Thirty seconds after
the initiation of such venting, the supply line is
repressurized with the trailer test rig (Figure 1).
Thirty seconds after the initiation of such
repressurizing of the supply line, the front supply
line is vented to the atmosphere. This procedure is
conducted either by connection and disconnection
of the supply line coupling or by use of a valve

installed in the supply line portion of the trailer
test rig near the supply line coupling. (56 F.R.
26927— June 12, 1991. Effective: December 9,
1991.)]

S5.7 Emergency brake system— trucks and
buses. Each vehicle shall be equipped with an
emergency brake system which, under the condi-
tions of S6. 1, conforms to the requirements of
S5.7.1 through S5.7.3. However, the truck portion
of an auto transporter need not meet the road test
requirements of S5.7.1 and S5.7.3.

55.7.1 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 81, 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, 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 service 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.

55.7.2 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.

55.7.3 Towing vehicle emergency brake
requirements. In addition to meeting the other
requirements of S5.7, a vehicle designed to tow
another vehicle equipped with air brakes shall —

(a) In the case of a truck-tractor in the
unloaded condition and a single unit truck which
is capable of towing an air-brake equipped
vehicle and is loaded to gross vehicle weight rat-
ing, 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 con-
trol line from the towing vehicle vented to the
atmosphere in accordance with S6.1.14;

(b) In the case of a truck-tractor loaded to gross
vehicle weight rating, be capable of meeting
S5.7.1 by operation of the service brake control
only, with the aid control line from the towing

PART 571; S121

(Rev. 6/12/91)

vehicle vented to the atmosphere in accordance
with S6. 1.14; and

(c) Be capable of modulating the air in the sup-
ply 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 specified
inS5.7.1.

[S5.8 Trailer pneumatic system failure
performance. Each trailer shall meet the require-
ments of S5.8.1 through S5.8.3. (56 F.R. 50666—
October 8, 1991. Effective: October 8, 1992.
Optional compliance: November 7, 1991.)]

[S5.8.1 Emergency braking capability. 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 S5.6.2 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 confonns to
S5.6 and that applies with the force specified in
S5.6.1 or S5.6.2 when the air pressure in the sup-
ply line is at atmospheric pressure; or

(b) An emergency system that automatically
applies the service brakes when the service res-
ervoir is at any pressure above 20 Ib./in.- and the
supply line is at atmospheric pressure. However,
any agricultural commodity trailer, heavy hauler
trailer, or pulpwood trailer shall meet the require-
ments of S5.5.1 or, at the option of the manufac-
turer, the requirements of §393.43 of this title.
(56 F.R. 50666— October 8, 1991. Effective: Octo-
ber 8, 1992. Optional compliance: November 7,
1991.)]

[S5.8.2 Supply line pressure retention. Effec-
tive October 8, 1992, or at the manufacturer's
option effective November 7, 1991, any single
leakage type failure in the service brake system
(except for a failure of the supply line, a valve
directly connected to the supply line or a compo-
nent of a brake chamber housing) shall not result
in the pressure in the supply line falling below 70
p.s.i., measured at the forward trailer supply cou-
pling. A trailer shall meet the above supply line
pressure retention requirement with its brake sys-
tem connected to the trailer test rig shown in Fig-
ure 1 , with the reservoirs of the trailer and test rig
initially pressurized to 100 p.s.i., and the regulator
of the trailer test rig set at 100 p.s.i.

[S5.8.3 Automatic application of parking
brakes. Effective October 8, 1992, or at the
manufacturer's option effective November 7, ^
1991, with an initial reservoir system pressure of "
100 p.s.i. and initial supply line pressure of 100
p.s.i., and if designed to tow a vehicle equipped
with air brakes, with a 50-cubic-inch test reservoir
connected to the rear supply line coupling, and
with any subsequent single leakage type failure in
any other brake system, of a part designed to con-
tain compressed air or brake fluid (excluding fail-
ure of a component of a brake chamber housing
but including failure of any diaphragm of a brake
chamber which is common to the parking brake
system and any other brake system), the parking
brakes shall not provide any brake retardation as
a result of complete or partial automatic applica-
tion of the parking brakes. (56 F.R. 50666— Octo-
ber 8, 1991. Effective: October 8, 1992. Optional
compliance: November 7, 1991.)]

S6. Conditions. The requirements of S5 shall
be met by a vehicle when it is tested according to
the conditions set forth below, without replacing
any brake system part or making any adjustments
to the brake system except as specified. Unless
otherwise specified, where a range of conditions is A
specified, the vehicle must be capable of meeting
the requirements at all points within the range. On
vehicles equipped with automatic brake adjusters,
the automatic brake adjusters must remain acti-
vated at all times. Compliance of vehicles manu-
factured in two or more stages may, at the option
of the final-stage manufacturer, be demonstrated
to comply with this standard by adherence to the
instructions of the incomplete vehicle manufac-
turer provided with the vehicle in accordance with
S568.4(a)(7)(ii) and § 568.5 of title 49 of the Code
of Federal Regulations.

S6.1 Road test condition.

S6.1.1 Except as otherwise specified, the vehicle
is loaded to its gross vehicle weight rating, distrib-
uted proportionally to its gross axle weight rat-
ings. During the burnish procedure specified in
S6.1.8, truck tractors shall be loaded to their
GVWR, by coupling them to an unbraked flatbed
semitrailer, which semitrailer shall be loaded so
that the weight of the tractor-trailer combination ^
equals the GVMR of the tmck tractor. The load ^
on the unbraked flatbed semitrailer shall be

(Rev. 10/8/91)

PART 571: S121-12

located so that truck tractor's wheels do not lock
during burnish.

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 12-foot wide, level, straight
roadway having a skid number of 81, inclusive,
chosen at the option of the manufacturer. The
vehicle is aligned in the center of the roadway at
the beginning of the stop.

56.1.8 The brakes are burnished before testing in
accordance with S6. 1.8.1. However, for vehicles
with parking brake systems not utilizing the serv-
ice brake friction elements, burnish the friction
elements of such systems prior to the parking
brake test according to the manufacturer's rec-
ommendations.

S6. 1.8.1 [Vehicles manufactured before Septem-
ber 1, 1993 may be burnished according to the
procedures set forth in S6. 1.8. 1(a) or S6. 1.8. 1(b)
of this section, at the manufacturers option.
Vehicles manufactured on or after September 1,
1993 shall be burnished according to the proce-
dures set forth in S6. 1.8. 1(b) of this section.

Table IV.

1 175 40 to 20 mph.

2 25 45 10 20 mph.

3 25 50 to 20 mph.

4 25 55 to 20 mph.

5 250 60 to 20 mph.

(a) 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
fpsps, or at the vehicle's maximum deceleration
rate, if not less than 10 fpsps, in the sequence
specified. Except where an adjustment is speci-
fied, after each brake application accelerate to the
next speed specified 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 any speed
specified 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, whichever occurs first.
If during any of the brake applications specified
in Table IV the hottest brake reaches 550°F, make
the remainder of the 500 brake 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. However, if at a snub condition of 40 to 20
mph, the temperature of the hottest brake exceeds
550°F, make the remainder of the 500 brake
applications from that snub condition, without
regard to brake temperature. The brakes shall be
adjusted three times during the burnish procedure,
after 125, 250, and 375 snubs and after complet-
ing this burnish, with each adjustment made in
accordance with the manufacturer's recommenda-
tions. Any automatic 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 hot-
test 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
temperature of the hottest brake on a rear axle by
100°F or more.

(b) With the transmission in the highest gear
appropriate for a speed of 40 mph, make 500
snubs between 40 mph and 20 mph at a decelera-
tion rate of 10 fpsps, or at the vehicle's maximum
deceleration rate if less than 10 fpsps. Except
where an adjustment is specified, after each brake
application accelerate to 40 mph and maintain
that speed until making the next brake application
at a point 1 mile from the initial point of the pre-
vious brake application. If the vehicle cannot
attain a speed of 40 mph in 1 mile, continue to
accelerate until the vehicle reaches 40 mph or
until the vehicle has traveled 1.5 miles from the
initial point of the previous brake application.

PART 571; S121-13

whichever occurs first. Any automatic pressure
limiting valve is in use to limit pressure as
designed. The brakes shall be adjusted three times
during the burnish procedure, in accordance with
the manufacturer's recommendations, after 125,
250, and 375 snubs, and shall be adjusted after
burnish in accordance with the manufacturer's
recommendations.] (53 F.R. 8190— March 14,
1988. Effective: September 11, 1988.)

56.1.9 Static parking brake tests for a semi-trailer
are conducted with the front end supported 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, a truck-tractor is tested at its gross vehicle
weight rating by coupling it to a flatbed
semitrailer (hereafter, control trailer) as specified
inS6.1.10.1 toS6.1.10.7.

56.1.10.1 The control trailer conforms to this
standard.

56.1.10.2 The center of gravity of the loaded con-
trol 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 center-
line 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 com-
bined gross axle weight rating of 32,000 lb and a
length, measured from the transverse centerline
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 rat-
ing, with the tractor's fifth wheel adjusted so that
the load on each axle measured at the tire-ground
interface is most nearly proportional to the axles'
respective gross axle weight ratings.

56.1.10.6 Test equipment specification. The

control trailer's service brakes are capable of stop-

ping 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 multiplying the value 68,
90, 115, 143, 174, 208, or 245 (corresponding to
a speed of 30, 35, 40, 45, 50, 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 specified
in S6. 1.10.5, the trailer service reservoirs pressur-
ized to 100 lb./in.2, and the trailer loaded so that
its axle is at gross axle weight rating and its king-
pin is at empty vehicle weight. The stopping dis-
tance is measured from the point at which move-
ment of the valve controlling the trailer brakes
begins. The service brake chambers 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 control-
ling the trailer brakes begins.

S6.1.10.7 Test equipment specification. The

control trailer's emergency brakes are capable of A
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 multiplying 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 controlling
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 lb./
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 control-
ling the trailer's spring parking brakes begins.

S6.1.11 Special drive conditions. A vehicle
equipped with an interiocking axle system of a
front wheel drive system that is engaged and dis- ^
engaged by the driver is tested with the system \

disengaged.

PART 571; S121-14

56.1.12 Liftable axes. A vehicle with a hftable
axle is tested at gross vehicle weight rating with

\ the liftable axle down and at unloaded vehicle
weight with the liftable axle up.

56.1.13 [Trailer test rig. The trailer test rig
shown in Figure 1 is calibrated in accordance with
the calibration curves shown in Figure 3. For the
requirements of S5.3.3.1 and S5.3.4.1, the pressure
in the trailer test rig reservoir is initially set at 100
p.s.i. for actuation tests and 95 p.s.i. for release
tests.

(b) The trailer test rig shown in Figure 1(a) 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 res-
ervoir from 95 to 5 Ib./in.^ in 0.22 second meas-
ured from the first movement of the service brake
control to release service brake pressure. (54 F.R.
18890— May 3, 1989. Effective: June 2, 1989.)]

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 atmosphere 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 emer-
gency 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.

S6.2 Dynamometer test conditions.

S6.2.1 The dynamometer inertia for each wheel is
equivalent to the load on the wheel with the axle
loaded to its gross axle weight rating. For a
vehicle having additional gross axle weight ratings
specified for operation at reduced speeds, the
GAWR used is that specified for a speed of 50

mph, or, at the option of the manufacturer, any
speed greater than 50 mph.

56.2.2 The ambient temperature is between 75°F
and 100°F.

56.2.3 Air at ambient temperature is directed uni-
formly 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 2. The
thermocouple is outside any center groove.

56.2.5 The rate of brake drum or disc rotation on
a dynamometer corresponding to the rate of rota-
tion on a vehicle at a given speed is calculated by
assuming a tire radius equal to the static loaded
radius specified by the tire manufacturer.

56.2.6 Brakes are burnished before testing as fol-
lows: Place the brake assembly on an inertia
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 termpeature 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
temperamre on each stop of not less than 450°F
and not more than 550°F. The brakes shall be
adjusted three times during the burnish procedure,
after 100, 200, and 300 stops, and at the conclu-
sion of the burnishing, in accordance with the
manufacturer's recommendations.

56.2.7 The brake temperature is increased to a
specified level by conducting one or more stops
from 40 mph at a deceleration of 10 fps. 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; S121-15

(Rev. 5/3/89)

Va" L.D. Line

0^€>r

1000 in3
Reser-
voir

Control
Valve

(mvJ — QRV HIMrj

30' - W L.D. Line
(Straight or Coiled)

Shop
Air

I 30' - ^/6"

■ Control Line
Glad Hand

I.D. Line (Straight or Coiled)

Supply Line
Glad Hand

SV —Shut-off Valve

R — Regulator (set at 1 00 psi for actuation tests and 95

psi for release test)
CV —Check Valve

MV — Metering Valve (Variable or Fixed)
QRV— Quick Release Valve

Figure 1 .—Trailer Test Rig.
(56 F.R. 50666— October 8, 1991.)]

TRACTOR PROTECTION VALVE

(OPTIONAL)

SERVICE BRAKE PEDAL

Figure la.— Trailer Test Rig
PART 571; 8121— Art Page 1

(Rev. 5/3/89)

PART 571; S121-16

0.295 DIA MAX-

CO DRILL NO. 31
0.100 MAX DEPTH
BEFORE GRIND

GRIND TO 1/8-
MAX BEFORE
PLACING IN LINING

Figure 2. — Thermocouple Installation

PART 571; S121-17

100 -i

20 —

Initial Valve Movement & Release

(Pressure vs Time for
50 in3 Test Reservoir)

Apply

60 psi
0.35 sec

/- Initial Valve Movement & Apply

Release

95-5 psi 0.7 sec

0.1 0.2 0.3 0.4 0.5 0.6

Time (Sec.) fromlnitial Valve Movement
Figure 3.— Calibration Curves
PART 571 : SI 21— Art Page 2

0.7

(Rev. 5/3/89)

PART 571: S121-18

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY

STANDARD NO. 131

School Bus Pedestrian Safety Devices

(Docket No. 90-01 ; Notice 3)
RIN 2127-AE33

ACTION: Final rule; response to petition for
reconsideration.

SUMMARY: This rule amends certain provisions
in Standard No. 131, School Bus Pedestrian Safety
Devices (49 CFR 571.131) which requires new
school buses to be equipped with a stop signal
arm. Specifically, the amendment requires the stop
signal arm to be aligned relative to the lower edge
of the passenger window. In addition, with respect
to stop arms equipped with lights to meet the
standard's conspicuity requirement, this notice
amends the flash rate so that it more closely cor-
relates to the most recent recommended practice
of the Society of Automotive Engineers. These
amendments will increase the effectiveness of stop
signal arms by improving their visibility to other
motorists.

EFFECTIVE DATE: The amendment becomes
effective September 2, 1992.

SUPPLEMENTARY INFORMATION:

L Background

On May 3, 1991, NHTSA published a final
rule establishing a new Federal motor vehicle
safety standard requiring new school buses to be
equipped with a stop signal arm. (56 FR 20363).
A stop signal arm is a device patterned after
conventional "STOP" signs and attached to the
left side of a school bus. When the school bus
stops, the stop signal ami autoinatically extends
outward from the bus. Its purpose is to alert
motorists that a school bus is stopping or has
stopped. The standard specifies requirements
about the stop signal arm's appearance, size, con-
spicuity, operation and location.

The agency established this new safety standard
after reviewing the available information, includ-
ing the docket comments, the Fatal Accident
Reporting System (FARS) data, and a report

issued by the National Academy of Sciences enti-
tled "Improving School Bus Safety," (Special
Report No. 222). The agency determined that a
safety need exists for better controlling the move-
ment of vehicles passing stopped school buses
during the loading and unloading of passengers.

n. Petitions For Reconsideration

NHTSA received two petitions for reconsider-
ation of the stop signal arm rule, one was a peti-
tion from the California Department of Education
(DOE) requesting a change in the requirement
regarding the height at which a stop signal arm
should be located. DoE asked that the reference
to the lower edge of the driver's window frame
in SS.4.1(b) be deleted, stating that some school
bus models are designed so that the lower edge
of the driver's side window is lower than the side
windows at the passenger seats. The petitioner
believed that installation of the stop signal arm
relative to the lower edge of the driver's window
could reduce the visibility of the stop signal arm
to other motorists and thus reduce the arm's
effectiveness. The California DOE recommended
that the reference in S5.4.1(b) be changed to the
lower edge of the passenger windows.

The other petition was from Epicor Industries,
a manufacturer of turn siqnals, hazard warnings
and alternating flashers. It requested that the
agency change the requirements for the flash rate
for stop signal arm lights under S6.2.2 to conform
with the most recent version of SAE J 1054,
"Warning Lamp Flashers, (October 1989). The
petitioner stated that such an amendment would
assure that the two lamps would flash alternately
and have "on"times that meet an accepted stand-
ard and have been proven effective. The previous
version of SAE J 1054 (January 1977), which was
used by NHTSA to develop the final requirements
of S6.2.2, was determined by the SAE to be
incorrectly written. Epicor also requested that
Standard No. 131 be amended to include a provi-

PART 131— PRE- 13

sion requiring all replacement parts for stop signal
arms to comply with the requirements of the
standard similar to the provisions of S5.7 in
Standard No. 108, Lamps, Reflective ment.
Devices, and Associated

III. Agency's Review of The Petitions For
Reconsideration

2. Reference Plane for Stop Signal Arm's Loca-
tion

In the final rule, NHTSA specified location
requirements applicable to the stop signal arm,
based on the goal of standardization, the views of
State school transportation personnel about effec-
tive locations for stop signal arms, typical loca-
tion of these devices, and the Vehicle Safety
Act's directive that the safety standards be objec-
tive. Section SS currently specifies that school
buses be equipped with at least one stop signal
arm installed on the left side of the bus so that,
when extended, (1) it is perpendicular to the side
of the bus, plus or minus five degrees, (2) it has
the top edge of the octagon parallel to and within
6 inches of a horizontal plane passing through the
lower edge of the driver's window frame, and (3)
its vertical centerline is at least 9 inches away
from the school bus body. The agency stated that
these requirements will provide uniform location
specifications while providing users flexibility to
install stop signal arms consistent with their
experiences with these devices. The location
requirements are also intended to ensure that the
stop signal arms are visible to motorists trailing
and approaching stopped school buses.

As mentioned above, California DoE requested
that S5.4.1(b) be amended so that the reference
plane passes through the lower edge of the pas-
sengers' windows instead of the lower edge of the
driver's window. The petitioner believed that this
change was necessary to accommodate the new
practice of designing some school buses so that
the driver's window is lower than the passengers"
windows.

NHTSA notes that the aqency's decision in the
final rule to specify the lower edge of the driver's
window was based on the assumption that the
lower edge of the driver's window and pas-
sengers' windows were all in the same horizontal
plane. While this assumption remains valid in
most situations, the agency is aware that an
increasinq number of new school buses are being
designed so that the driver's side window is lower

than the passenger side windows. The agency
believes that new school buses are being designed
in this manner to improve school bus driver visi-
bility of student pedestrians in front of and along •
side of the school bus.

NHTSA has decided to amend the requirements
of S5.4.1(b) to require that the top edge of the
stop signal arm be aligned with the lower edge of
the frame of the passenger window immediately
behind the driver's window. The agency believes
that specifying this window as the reference will
ensure that stop signal arms are more visible to
other motorists, since some school buses are
designed with the bottom of the driver's window
being well below that of the passengers' win-
dows. Under the May 1991 final rule, as the
lower edge of the driver's window gets closer to
the ground, so does the signal stop arm, thereby
reducing its visibility to other motorists, and thus
its effectiveness.

The agency anticipates that this amendment
will not result in any adverse impact to school
bus manufacturers or users that were planning to
install the stop signal arm relative to the lower
edge of the driver's window. In most buses, the
driver's window is on the same plane as the pas-
sengers' windows. In addition, the agency has •
reviewed those new bus designs with lower driver
windows and believes that installing the stop sig-
nal arm relative to the lower edge of the pas-
sengers' windows will not result in any additional
compliance problems for manufacturers.

B. Flash Rate

In the final rule, the agency determined that a
stop signal arm must either be reflectorized or
have flashing lamps to provide increased con-
spicuity, or both. The final rule stated that if
flashing lamps are used, they must comply with
the requirements for color, flash rate, and vibra-
tion, moisture, dust, corrosion, photometry, and
warpage, as set forth in S6.2. The notice stated
that the tests for flash rate were patterned after
the tests in the Society of Automotive Engineer's
(SAE's) Recommended Practice, J 1054, Warning
Lamp Alternating Flashers (January 1977).
Specifically, S6.2.2 of the final rule states:

The lamps on each side of the stop signal arm,
when operated at the manufacturer's design
load, shall flash at a rate of 60-120 flashes per ^
minute with a current "on" time of 50 percent.

PART 131— PRE- 14

The petition from Epicor requested that the
^ requirements for the flash rate be patterned after
^ the more recent SAE Recommended Practice for
ahemating flashers promulgated in October 1989.
The October 1989 Recommended Practice cleared
up technical problems caused by the existence of
two SAE Recommended Practices dealing with
alternating flashing lamps — SAE J 1054 and SAE
J 1104. While J 1054 described the performance
parameters for a flasher, J 1104 specified how to
assure that a particular flasher design conformed
to the performance parameters. In October 1989,
SAE revised J 1054 to incorporate the pertinent
features and allowable elements of both SAE
Recommended Practices, thus eliminating the
need for J 1104. In doing so. SAE substituted the
flash rate conditions of J 1104 for those in J 1054.
After reviewing the modified SAE rec-
ommended practice, NHTSA has decided to pat-
tern S6.2.2 after the October 1989 SAE Rec-
ommended Practice, J 1054. Given that the SAE
has determined that the January 1977 version of
J 1054 is technically incorrect, the agency believes
that S6.2.2 should be revised to reflect the lan-
guage adopted in the October 1989 version of
^ J 1054.

C. Replacement Equipment

The final rule specified that Standard No. 131
is a vehicle standard that applies to new school
buses. The Standard does not apply to stop signal
arms sold in the aftermarket. Nor do the Stand-
ard's provisions apply to stop signal ami replace-
ment parts.

Epicor requested that Standard No. 131 be
amended to include a section requiring that all
replacement bulbs and lenses for stop signal arms
meet the requirements of the standard. It was sug-
gested that such an amendment would parallel
S5.7 of Standard No. 108, which requires replace-
ment lights to comply with that standard.
Requesting that Standard No. 131 be amended to
make the replacement bulbs and lenses subject to
the requirements of the standard is based on the
assumption that such a requirement is necessary
for safety. Specifically, the petitioner stated that
the amendment would ensure that the standard is
"not abused over time as worn parts and compo-
nents are replaced.'"
% In determining whether to extend Standard No.

131 's requirements to aftermarket replacement
parts, the agency contacted Specialty Manufactur-

ing Company, the largest manufacturer of stop
signal arms. Specialty Manufacturing explained
that the bulbs installed in the flashing lamps are
the same bulbs used in passenger car stop lamps.
In addition, the replacements are normally bought
directly from Specialty Manufacturing because the
lamp lens has a unique shape and hole pattern.

NHTSA has decided not to extend Standard
No. 131 to replacement parts. The agency dis-
agrees with the petitioner's contention that
inferior replacement parts will be used unless the
Standard is amended. The agency notes that the
only replacement bulbs available can be assumed
to be in compliance with the standard's require-
ments for stop signal arm bulbs since those bulbs
are the same as the bulbs required to comply with
the requirements for passenger car replacement
lamps under S5.7 of Standard No. 108. The only
known source of replacement lamp lens is the
original manufacturer, and the agency does not
anticipate the entry of low quality replacement
bulbs and lamps into the market given the low
cost and low volume of this market. Accordingly,
the agency has decided to deny the petitioner's
request to establish performance requirements for
replacement equipment.

NHTSA has determined that an immediate
effective date is in the public interest. The amend-
ments made by this notice impose no new
requirements but instead either increase manufac-
turer flexibility or are for purposes of clarification
or correction. Since the new Standard No. 131 is
effective September 1, 1992, the agency has
determined that it is in the public interest to have
these amendments become effective at the same
time. Absent these amendments, manufacturers
availing themselves to this flexibility would be
unable to certify that their school buses comply
with Standard No. 131.

PART 131— PRE- 15

petition or reconsideration or other administrative
proceedings before parties may file suit in court.
In consideration of tfie foregoing, 49 CFR Part
571 is amended as follows:

1. The authority citation for Part 571 of Title
49 continues to read as follows:

PART 571— [AMENDED]

Authorit}^: 15 U.S.C 1392, 1401, 1403, 1407;
delegation of authority at 49 CFR 1 .50.

2. In Section 571.131, the title of the section to
read as follows:

§571.131 Standard No. 131; School bus pedes-
trian devices.

3. In Standard No. 131, S5.4 is revised to read
as follows:

S5.4 The stop signal arm shall be installed on the
left side of the bus.

S5.4.1 The stop signal arm shall be located such
that, when in the extended position:

(a) The stop signal arm is perpendicular to the
side of the bus, plus or minus five degrees;

(b) The top edge of the stop signal arm is par-
allel to and not more than 6 inches from a hori-
zontal plane tangent to the lower edge of the
frame of the passenger window immediately
behind the driver's window; and

S5.4.2 A second stop signal arm may be installed
on a school bus. That stop signal arm shall comply
with S5.4andS5.4.1.

4. In Standard No. 131, S6.2.2 is revised to
read as follows:

S6.2.2 Flash Rate. The lamps on each side of
the stop signal arm, when operated at the manu-
facturer's design load, shall flash at a rate of 60
to 120 flashes per minute with a current "on"
time of 30 to 75 percent. The total of the percent
current "on" time for the two terminals shall be
between 90 and 110 .

Issued on August 28, 1992.

STOP

I-

stroke width of letters
20 mm (079 inch)

im (0.47 inch)

Figure 1 . Characteristics of Stop Signal Device

Marion C. Blakey
Administrator, Acting

57 F.R. 40131
September 2, 1992

PART 131— PRE- 16

MOTOR VEHICLE SAFETY STANDARD NO.
School But Pedestrian Safety Devices

131

51. Scope. This standard establishes require-
ments for devices that can be installed on school
buses to improve the safety of pedestrians in the
vicinity of stopped school buses.

52. Purpose. The purpose of this standard is to
reduce deaths and injuries by minimizing the like-
lihood of vehicles passing a stopped school bus
and striking pedestrians in the vicinity of the bus.

53. Application. This standard applies to school
buses.

54. Definitions.

Stop signal arm means a device that can be
extended outward from the side of a school bus
to provide a signal to other motorists not to pass
the bus because it has stopped to load or dis-
charge passengers.

55. Requirements. Each school bus shall be
equipped with a stop signal arm meeting the
requirements of S5.1 through S5.5 as depicted in
Figure 1.

STOP

I 150 mm (

Figure 1. Cliarateristics of Stop Signal Device

55.2 The stop signal arm shall be red on both
sides, except as provided in S5.2.1 and S5.2.2, and
S5.2.3.

55.2.1 The stop signal arm shall have a white
border at least 12 mm (0.47 inches) wide on both
sides, except as provided in S5.2.3.

55.2.2 The stop signal arm shall have the word
"STOP" displayed in white upper-case letters on
both sides, except as provided in S5.2.3. The let-
ters shall be at least 150 mm (5.9 inches ) in
height and have a stroke width of at least 20 mm
(0.79 inches).

55.2.3 When two stop signal arms are installed
on a school bus, the rear-most stop signal arm
shall not contain any lettering, symbols, or mark-
ings on the forward side.

55.3 Conspicuity. The stop signal arm shall
comply with either S5.3.1 or S5.3.2, or both.

55.3.1 The entire surface of both sides of the
stop signal arm shall be reflectorized with type III
retroreflectorized material that meets the minimum
specific intensity requirements of S6. 1 and Table
1. When two stop signal arms are installed on a
school bus, the forward side of the rearmost stop
signal arm shall not be reflectorized.

55.3.2 Each side of the stop signal arm shall
have at least two red lamps that meet the require-
ments of S6.2. The lamps shall be centered on the
vertical centerline of the stop arm. one of the
lamps shall be located at the extreme top of the
stop arm and the other at its extreme bottom.

55.4 The stop signal arm shall be installed on the
left side of the bus.

S5.1 The stop signal arm shall be a regular octa-
gon which is at least 450 mm x 450 mm (17.72
inches x 17.72 inches) in diameter.

S5.4.1 The stop signal arm shall be located such
that, when in the extended position:

(a) The stop signal arm is perpendicular to the
side of the bus, plus or minus five degrees;

PART 131-1

(b) [The top edge of the stop signal aim is par-
allel to and not more than 6 inches from a hori-
zontal plane tangent to the lower edge of the
frame of the passenger window immediately
behind the driver's window; and

(c) The vertical centerline of the stop signal
arm is not less than 9 inches away from the side
of the school bus. (57 F.R. 40131— September 2,
1992. Effective: September 2, 1992)]

S5.4.2 A second stop signal arm may be installed
on a school bus. That stop signal arm shall comply
withS5.4andS5.4.1.

S5.5 The stop signal arm shall be automatically
extended in such a manner that it complies with
S5.4.1, at a minimum whenever the red signal
lamps required by S5.1.4 of Standard No. 108 are
activated; except that a device may be installed
that prevents the automatic extension of a stop sig-
nal arm. The mechanism for activating the device
shall be within the reach of the driver. While the
device is activated, a continuous or intermittent
signal audible to the driver shall sound. The
audible signal may be equipped with a timing
device requiring the signal to sound for at least 60
seconds. If a timing device is used, it shall auto-
matically recycle every time the service entry door
is opened while the engine is running and the
manual override is engaged.

S6 Test Procedures.

S6.1 Reflectivity Test. When tested under the
condhions specified in S6.2 (b), (c), and (d) of
Federal motor vehicle safety standard 125, Warn-
ing Devices, (49 CFR 571.125), the retroreflective
materials shall meet the criteria specified in table
1.

TABLE 1 — Minimum Specific Intensity Per
Unit Area (SIA)
(Candelas per Footcandle Per Square Foot)
Type III Retroreflecsive Element Material

A — Glass Bead Retroreflective Element Material

B — Prismatic Retroreflective Element Material

Observation Angle (°) ^nl^eT"^) "^''"'^ ^^^

Observation

(°)

Angle

Entrance
Angle (°)

White

Red

0.2

-4

250

0.2

+30

150

0.5

-4

0.5

+30

0.2

-4

250

0.2

+30

13.3

0.5

-4

200

0.5

S6.2 Lighting Tests.

56.2.1 Color. The procedure shall be done in
accordance with the Society of Automotive Engi-
neers (SAE) J578, Color Specification (May
1988), 1990 SAE Handbook, Society of Auto-
motive Engineers, Inc. Along with the incorpora-
tion by reference in S6.2.3, this incorporation by
reference was approved by the Director of the
FEDERAL REGISTER in accordance writh 5
U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from the Society of Automotive Engi-
neers, 400 Commonwealth Drive, Warrendale, PA
15096-0001. Copies may be inspected at Docket
Room, National Highway Traffic Safety Adminis-
tration, 400 Seventh Street, SW., Washington, DC
20590 or at the office of the FEDERAL REG-
ISTER, 800 North Capitol Street, NW., suite 700,
Washington, DC. When visually compared to the
light einitted from a filter/ source with a combina-
tion of chromaticity coordinates as explained in
SAE J578, Color Specification (May 1988), within
specific boundaries [y = 0.33 (yellow boundary)
and y = 0.98 — x (purple boundaiy)] the color of
light emitted from the test object shall not be less
saturated (paler), yellower, or purpler. The test
object shall be placed perpendicular to the light
source to simulate lamps on stop signal arms. In
making visual comparisons, the light from the test
object shall light one portion of a comparison field
and the light from the filter/source standard shall
light an adjacent area. To make a valid visual
comparison, the two fields to be viewed shall be
of near equal luminance.

56.2.2 Flash Rate. [The lamps on each side of
the stop signal ami, when operated at the manu-
facturer's design load, shall flash at a rate of 60
to 120 flashes per minute with a current "on"
time of 30 to 75 percent. The total of the percent
current "on" time for the two terminals shall be
between 90 and 110. (57 F.R. 40131— September 2,
1992. Effective: September 2, 1992)]

PART 131-2

S6.2.3 Vibration, Moisture, Dust, Corrosion, shall meet, the criteria for vibration, moisture,

Photometry, and Warpage Tests. The proce- dust, corrosion, photometry, and warpage in SAE

dure shall be done in accordance with the Society J57S, Tests for Motor Vehicle Lighting Devices

of Automotive Engineers (SAE) J575, Tests for and Components, (July 1983) and SAE J1133,

Motor Vehicle Lighting Devices and Components, School Bus Stop Arm, (April 1984) under the test

(July 1983) and Society of Automotive Engineers conditions specified herein.
(SAE) J1133, School Bus Stop Arm, (April 1984),

1990 SAE Handbook, Society of Automotive 56 F.R. 20363

Engineers, Inc. Lamps and hghting components IVIay3, 1991

PART 131-3

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE

SAFETY STANDARD NO. 213

Child Restraint Systems

(Docket No. 74-09; Notice 26)
RIN: 2127-AD46

ACTION: Final rule.

SUMMARY: This rule amends Standard 213. Child
Restraint Systems, to require manufacturers of
child restraints to provide a postage paid registra-
tion form with each seat. The rule also amends the
standard to require manufacturers to provide
information to purchasers about the importance of
registering the restraint, as well as information
necessary to enable subsequent owners to register
the restraint. In addition to amending Standard
213, this rule adds a new Part 588 in title 49,
CFR, that requires manufacturers to keep records
of the names and addresses of persons who have
returned a registration form.

These requirements will improve the effective-
ness of manufacturer campaigns to recall child
restraints that contain a safety-related defect or
fail to conform to Standard 213 by requiring
manufacturers to take steps that will increase their
ability to inform owners of particular child
restraints about defects or noncompliances in
those restraints and by encouraging child restraint
owners to register their restraints. The require-
ments will also assist NHTSA in determining
whether a child safety seat manufacturer has com-
plied with its notification re.sponsibilities estab-
lished by the National Traffic and Motor Vehicle
Safety Act.

This rulemaking proceeding commenced in
response to a December 1989 petition for rule-
making from the Center for Auto Safety and
Consumer Action of San Francisco.

EFFECTIVE DATE: The amendment is effective
March 9, 1993.

SUPPLEMENTARY INFORMATION:

General introduction
This rule amends Standard 213 to establish a
registration program for child restraint systems.

The rule requires manufacturers to provide a
standardized, postage-paid registration form with
each restraint system. Manufacturers of built-in
restraints installed in new vehicles are excluded
from the requirement because the manufacturers
are able to identify the vehicle owners through
motor vehicle registration files and directly notify
them of a recall concerning the built-in restraints.

The rule standardizes the text and layout of the
registration form to increase the likelihood that a
purchaser will register the restraint. On each
form, manufacturers must preprint their return
address, along with information identifying the
model name or number of the restraint to which
the form is attached. The form must be attached
to the restraint to ensure that a purchaser will
notice the form.

This rule also requires manufacturers to keep
records of the names and addresses of persons
who have returned a registration form. The manu-
facturers must maintain the record for at least six
years from the date of manufacture of the seat.

NHTSA proposed the registration program in a
notice of proposed rulemaking (NPRM) published
on February 19. 1991 (56 FR 6603). Today's rule
differs from the NPRM in various respects. The
registration form is simplified. The labeling on
the restraint must include both an address and a
telephone number for the manufacturer. Cost esti-
mates are slightly higher. The recordkeeping
requirement of six years from the restraint's date
of manufacture is two years less than was pro-
posed. These and other changes are discussed fur-
ther below.

This rule is intended to improve the percentage
of recalled restraints that are fixed in a recall
campaign for a noncompliance or defect. During
1981-1991, almost 18 million child restraints were
recalled. During this period, about 13 percent of
the child restraints involved in completed recall
campaigns were reported as "campaigned units."

PART 571: S 213— PRE-73

Campaigned units refer to those child restraints
that were reported remedied as well as those
restraints either removed from sale to the public
or removed from use by the public. (During 1981-
1989, approximately 6 million restraints were
recalled. About 10.5 percent of the restraints
involved in completed recall campaigns were
reported as campaigned units during this period.
During 1990-1991, almost 12 million child
restraints were recalled. Only about 1 1 percent of
the restraints involved in completed recall cam-
paigns were reported as campaigned during this
period.) In general, this indicates that the child
restraint campaign rate is considerably lower than
the campaign rate for motor vehicles (60.5 per-
cent for 1981-1991).

(At the time of the NPRM, the child restraint
average campaign completion rate was 22 percent.
That rate reflected the number of seats that had
been campaigned at the time of the NPRM. Dur-
ing the period 1990-1991, the average campaign
completion rate increased to about 27 percent.) It
should be noted that, even though the average
campaign completion rate averaged about 27 per-
cent during 1990-1991, for all campaigns in
aggregate only about 11 percent of the restraints
involved in completed recall campaigns were
reported as campaigned.

The low response rate for child restraints does
not seem a consequence of a lack of interest in
recalls on the part of the owners. The public
responded overwhelmingly to a December 1989
press conference by CAS on child seat recalls by
calling NHTSA. In the eight months following
that press conference, NHTSA's Auto Safety Hot-
line received over 30,000 calls from concerned
parents asking about recalls and the safety of
child seats. This intense interest in child safety
indicates that many owners are highly motivated
and would return a recalled seat for a remedy, if
they knew it had been recalled. Stated differently,
many owners might not have had the problem
remedied because notification of the recall failed
to reach them.

NHTSA proposed the registration program to
improve the dissemination of the recall informa-
tion directly to individual owners. In the past,
efforts to improve notice of a recall focused on
better disseminating the information indirectly,
i.e., to the general public. The agency decided to
change its focus to individual owners. If owners

are directly notified that their seat is recalled, the
response rate should increase.

Pursuant to a contract with the agency, ^B
National Analysts conducted a study of consum- ^B
ers' attitudes about the proposed registration pro-
gram and other child safety issues during the time
that the agency was developinq the NPRM. A
copy of the February 1991 report has been avail-
able in the docket. The researchers conducted four
group interviews ("focus groups"). Two groups
were interviewed in Orange, California and the
other two in Philadelphia, Pennsylvania. The
groups were comprised of people who acquired a
child restraint new and who use the restraint with
their child at least once a week. The participants
were asked to evaluate five different registration
fomis, three of which corresponded exactly to the
NPRM's alternative Figure 9a, options one
through three. The alternatives differed in how
they presented a motivational message for the
registration form.

National Analysts reported that participants in
all four groups were unanimous in their support
for a registration program. National Analysts con-
cluded that, based on the findings from the study,
"the great majority of child safety seat buyers are ^m
likely to appreciate and respond to a recall reg- ^|
istration program." The researchers reported that:
Participants also indicated that they would be
most likely to return a pre-addressed, postage-pre-
paid card with an uncluttered graphic design that
clearly and succinctly communicates the benefits
of recall registration, differentiates itself from a
warranty registration card, and requires minimal
time and effort on the participant's part. "Child
Safety Seat Registration: The Consumer View,"
National Analysts, February 1991.

Comments on the proposal
The agency received 22 comments on the
NPRM, from manufacturers, researchers, church
and consumer groups, state governments and pri-
vate individuals. The overwhelming majority of
the commenters supported a registration program.
With the exceptions discussed below, the com-
ments generally consisted of specific suggestions
regarding the format and language of the form,
the labeling on the restraint, and the record-
keeping part of the rule. Evenflo, Cosco and
Chrysler Corporation (a manufacturer of built-in ^B
systems) expressed concerns about the effective- ^H
ness of registration programs. Evenflo and Cosco

PART 571; S 213— PRE-74

also had cost concerns, which will be discussed in
the section on "Costs."

Evenflo believed that a registration program
would not be effective. Evenflo indicated that a
registration program for child restraints can be
compared to the "mandatory" registration
requirements that Congress in 1982 specifically
provided that the agency could not apply to
independent tire dealers. See, 158(b) of the
National Traffic and Motor Vehicle Safety Act of
1966. The mandatory registration program had
required all tire dealers, including independent
dealers, to obtain and send specified information
(i.e., the purchaser's name and address, the
dealer's name and address, and the identification
numbers of the tires) to the tire manufacturer.
("Independent tire dealers" means tire dealers
and distributors whose businesses are not owned
or controlled by a tire manufacturer or brand
name owner.)

Compliance with the mandatory registration
was uneven. While virtually all tires on new
vehicles were registered, about half of all replace-
ment tires were registered. Independent dealers
had registered only 20 percent of the requirement
tires they sold.

With the goals of improving cne registration
rate for tires sold by independent dealers and less-
ening the burden on the dealers. Congress prohib-
ited NHTSA from requiring those dealers to com-
ply with the mandatory registration program. In
place of the mandatory program for the dealers.
Congress directed NHTSA to establish a vol-
untary tire registration process. In the voluntary
process, which is in effect today, the independent
tire dealer furnishes a standardized registration
fonn to each purchaser after the dealer has first
filled in the tire identification number on the
form. Purchasers wishing to register their tire fill
in their name and address on the form and mail
the completed form to the tire manufacturer. The
form's postage is paid by the purchaser. The reg-
istration rate for the voluntary tire registration
program is about 1 1 percent.

In response to Evenflo, NHTSA disagrees that
the proposed registration process for child
restraints is comparable to the mandatory program
that had applied to independent tire dealers. In
contrast, the proposed child restraint program has
some similarities to the voluntary tire registration
program that Congress directed NHTSA to adopt
for the independent dealers. They are similar

because in both cases, the semi-completed reg-
istration form is provided to the purchaser. Per-
sons wishing to register their product may then do
so by filling in their name and address and mail-
ing the completed form to the restraint manufac-
turer.

However, even though similarities would exist
between the two programs, NHTSA does not
believe that the voluntary tire program is a good
surrogate for what might happen in the child
restraint program. First, in the child registration
program: (a) every child restraint will be provided
with a registration form attached to it; and (b)
every registration form will describe to purchasers
why the form should be filled and returned to the
child restraint manufacturer. As previously men-
tioned, even though registration rates for
independent tire dealers was about 1 1 percent, a
consumer survey indicated that only 22 percent of
these dealers' customers had received registration
fomis from their dealers, and that over 80 percent
of the independent dealers' customers did not
remember the dealer explaining the reasons why
the registration form should be returned to the
manufacturer. Second, consumers seem to be far
more likely to be concerned with child safety than
with tires, and therefore, they are more apt to fill
in a registration form on child restraints than on
tires. Third, the child restraint registration form is
postage paid, a feature that the National Analysts
study showed should have a positive effect on
registration rates. Other information also shows
the positive effect of providing the postage.
According to information from the Consumer
Product Safety Commission, warranty cards are
returned for chain saws at a rate of 20 to 30 per-
cent without postage paid; 40 percent with post-
age paid. Because of these differences, NHTSA
does not believe the voluntary tire registration
program is a good surrogate for what might hap-
pen in the child registration program.

Several commenters said that the registration
process would be more effective if it involved
more the retailer who sells the restraint to the
purchaser. The CAS suggested that the process
should "require consumers to register the child
restraint at time of purchase and as a condition of
the sale." The Coalition for Consumer Health and
Safety said that the registration form should be
"returned to the retailer at the point of sale,
instead of enclosed with the seat to be mailed in
by the consumer." Advocates for Highway and

PART 571; S 213— PRE-75

Auto Safety also believed that the form should be
completed by the consumer with the assistance of
the retailer at the time of purchase.

The NPRM explained why the agency did not
propose a seller registration process. The pre-
amble stated:

In deciding whether to propose mandating
registration by sellers or a lesser alternative, the
agency was mindful that the Vehicle Safety Act
does not provide NHTSA with explicit authority
to require mandatory registration of child safety
seats — i.e., to require sellers to register all seat
purchases. Because of these concerns, and
because child safety seats are sold to the public
through a complex distribution system involving
the manufacturer, major warehouse distributors,
local distributors, and a wide variety of retail out-
lets, NHTSA concluded that a registration pro-
gram for seats would have a greater likelihood of
success in actual practice if the responsibility for
registering were placed primarily on the manufac-
turer (to provide the card and registration
information) and the first owner (to fill out the
card and mail it). 56 FR at 6604.

NHTSA continues to believe that mandatory
registration would be undesirable for the reasons
stated in the NPRM. Further, a comparison can be
made to the tire registration program. Congress
found mandatory tire registration to be overly
burdensome for independent businesses. The
manufacture, distribution and sale of child seats is
accomplished through a complex distribution sys-
tem involving numerous retail outlets, large and
small. A mandatory registration program could
impose substantial burdens on these retailers.

Chrysler expressed concerns about the need for
registration. Chrysler stated, "we do question the
need for and value of the proposed registration
requirements, given that the agency's estimate for
card return rate is about 20 to 40 percent, and no
estimate is offered for the probable recall
response rate." Chrysler also stated that, because
the card return rate might be no higher than 20
to 40 percent, "the manufacturer should be
allowed the flexibility to determine for each
instance how owners are to be notified, taking
into account the nature of the particular defect or
cause of noncompliance." The agency does not
have information that would indicate the potential
reduction in injuries or fatalities resulting from a
registration requirement. The NPRM requested
comments about instances where a child was

injured in a safety seat that had been recalled by
the manufacturer, but not fixed before the
accident. No information was provided. Neverthe- ^n
less, the agency believes there is a need for reg- ^|
istration, to improve the notice end of a recall
campaign. Today's registration requirements
standardize the form to increase the likelihood
that the purchaser will register. Today's require-
ments will increase the likelihood that the reg-
istrant will hear of a recall and realize that the
recall pertains to the seat. These requirements
address the problems referred to by Safety Belt
Safe U.S.A. in its comment: "the vast majority of
safety seat owners either do not learn of the
recall/repair message; or.. .do not realize that pub-
licized recall campaigns apply to them." These
problems may have kept the recall response rate
low.

Several factors might work to optimize the reg-
istration rate for the child restraint program. First
of all, the public concern for child safety should
have a decidedly positive effect on the return rate.
Also, the child restraint registration form is
conspicuous to the purchaser and is postage paid,
features that should have a positive effect on reg-
istration rates.

With regard to flexibility, Chrysler implied that ^^
the registration program would obviate the need ^
for public notice of a recall. NHTSA disagrees.
Section 153(c)(3) of the Safety Act authorizes
NHTSA to require the notification to be provided
to known purchasers of the child restraint and to
the general public. The agency anticipates that it
would be appropriate to require public notice of
the recall, in addition to direct notification of reg-
istrants, to ensure that notice is provided to the
extent possible to owners who did not register, or
to those whose address on registration records is
not current or complete.

Cosco also had concerns about the program's
effectiveness. Cosco said that the effectiveness of
registration is lessened because "a significant
number of restraints are passed down from family
to family, sold in garage sales, etc."

NHTSA proposed the registration program
keeping in mind that child restraints are fre-
quently acquired "secondhand," as Cosco stated.
To address that situation, the agency proposed
labeling requirements to infonn secondhand own-
ers how to register with the manufacturer. When ^
the secondhand owners have registered, they can ^
be directly notified by the manufacturer if the

PART 571; S 213— PRE-76

restraint is recalled. Thus, the purpose of the reg-
istration program would be fulfilled for second-

A hand owners through the labeling provisions.

^ The wording of the exclusion of built-in

restraints has been slightly changed from the pro-
posal. The proposal excluded "a built-in child
restraint system installed in a vehicle by the
vehicle manufacturer." The rule excludes a "fac-
tory-installed buih-in child restraint system" from
the registration requirements, and defines the term
in S4 of Standard 213 as "a built-in child
restraint system that was installed in a motor
vehicle at the time of its delivery to a dealer or
distributor for distribution." The change from the
NPRM is intended only to simplify the wording
of the requirements portion of the standard.

1. Standardized Registration Form.

The NPRM proposed requirements to increase
the likelihood that the purchaser will notice the
form, fill it in and mail it.

Attached form. The NPRM proposed that the
form be attached to a "contactable surface" (the
term is defined in S4) of the restraint so that the
purchaser must, as a practical matter, notice and

^ handle the form after purchasing the restraint and

B before putting it into use.

Several commenters addressed the proposal that
the form be attached to a contactable surface.
Evenflo said that "the location of the forms
within the packaging or upon the product does
not increase the likelihood of registration. Rather,
it turns on the education of the consumer, their
spare time and their ready access to the U.S.
mail." In contrast. Safety Belt Safe said having
the form be attached so that the purchaser must
actively detach it will make it less likely that the
form will be lost.

National Analysts found that respondents in the
focus group study indicated that seeing and han-
dling the card are important to maximize registra-
tion rates:

There is also strong support for the registra-
tion card's being attached to the seat in such a
way that it cannot be used without first removing
the card. It is thought particularly important for
the card to be packaged separately from instruc-
tions, warranties and other material enclosed with
the CSS [child safety seat]. Suggestions include

^ directly attaching the card to the seat liner —

W although some question whether an adhesive
tacky enough to securely attach to the seat would

not leave the seat sticky — or attaching it by
means of a plastic tie, similar to those used to
attach price tags to clothes in department stores.

"Make it so you can't rip it off hut have to
use scissors because then you'll read it."

[Participant's quotation emphasized in text.]
(Id. at 29)

This rule adopts the requirement that the form
must be attached to the child restraint. The
National Analysts study indicates that the require-
ment will improve the likelihood that the form
will be noticed and read by the purchaser. How-
ever, the rule permits the form to be attached to
more surfaces than had been proposed. Under the
NPRM, the only permissible surfaces were
"contactable surfaces," i.e., surfaces contactable
by a dummy's head or torso during a compliance
test. Under the final rule, the form may be
attached to any surface of the restraint that con-
tacts any portion of the dummy when the dummy
is positioned in the system in accordance with
S6.1.2 of Standard 213. This change from the
NPRM is made to allow more flexibility in
selectinq a location for attaching the form.

Under a contactable surfaces requirement, the
form would have had to be attached to surfaces
only contactable by a dummy's head or torso,
since "contactable surface" in S4 is limited to
head and torso contacts. Thus, attaching the form
to parts of the seat cushion that contact the dum-
my's thighs would not have been allowed. Such
a prohibition does not appear warranted, since
attaching the form to surfaces other than
"contactable" ones meets the goal of the require-
ment that the purchaser will notice and handle the
form when detaching it.

Te.xt and format. The NPRM sought to
standardize the text and format of the registration
form to increase the likelihood that the purchaser
will fill it in. The agency proposed a two-sided,
two-part form that consisted of a motivational
message and boxed statement (top part) and a
postcard that the purchaser would fill in and mail
(bottom part). NHTSA proposed the two-part
form to ensure that the information on the form
can be easily read, and that the allotted space for
the purchaser's name and address would be suffi-
ciently large to permit the easy, legible recording
of all the necessary information.

Several commenters questioned the need to
standardize the form. Cosco said that each manu-

PART571: S 213— PRE-77

facturer may have differing needs for the forms,
which calls for flexibility. Ford Motor Company
said that manufacturers should be allowed to use
either a fold-over card or a two-part form, and
that details of the proposed form should be
optional to allow manufacturers the flexibility to
design a form that would better facilitate the
recording of the information from registrants.

In contrast, Safety Belt Safe said that a defi-
nite, prescribed format is desirable because it
"fits with the public image of important, official
forms," which will encourage people to register.

NHTSA is requiring the form to be standard-
ized to increase the likelihood that a purchaser
will register. The National Analysts study showed
that essentially the same text and format as those
adopted in this rule were effective in presenting
the necessary information legibly and eliciting a
favorable response from the purchaser, factors
that are needed to maximize registration rates.

The focus groups widely and enthusiastically
accepted the text and format of the parts of the
form that did not vary among the proposed
options {Id. at 10-14). (The reaction to the part of
the form that varied is also discussed below.)
National Analysts found that the participants
unanimously praised the boxed statement (top part
of proposed Figure 9b — the address side of the
form). "The boxed message. ..clearly and effec-
tively communicates what are perceived to be the
two most critical messages contained on the reg-
istration cards: That it is important. ..[and] [t]hat
this is a recall registration, not a warranty card."
Id. at 10.

The part of the form that the purchaser fills in
(bottom part of proposed figure 9a, the product
identification number and purchaser information
side) was found to draw —

a particularly positive response because it
requires minimal information and effort to com-
plete... CSS owners praise the fact that they are
only required to fill in their name and
address.... There is a strong preference to have the
serial, model number and manufacturing date
preprinted on the card as indicated on the proto-
types. Nearly all want the numbers printed on the
card. They feel that it saves them the trouble of
looking-and that any marginal addition of time
and effort serves as a potential barrier to comple-
tion and return. Id. at 12-14.

The portion of the form indicating that the reg-
istration postcard is prestamped and preaddressed
"is considered essential. ..Reaction to this was
uniformly enthusiastic." Id. at 12.

Because the focus groups' response to the
text and format of the unvarying parts of the pro-
posed form was extremely positive, NHTSA is
requiring use of the text and format. Prescribing
the text and format has the added benefit of
ensuring that commercial matters, such as market-
ing information, are excluded from the form. (In
addition, the regulatory text expressly prohibits
such information. See, 85. 8(c).) If marketing
information were allowed to be placed on the
forni, such information might cause purchasers to
misidentify the registration form as a warranty
card, which the agency seeks to avoid in view of
National Analysts' finding that participants gen-
erally had negative feelings toward warranty reg-
istrations (Id. at 14).

The rule prescribes the text and format for the
motivational message, the part of the form that
varied among the proposed options. National
Analysts found that it is possible for the text and
format of the message to elicit a negative
response from the purchaser. The text for option
two was widely criticized as appearing shallow or
manipulative. Id. at 19. The text for option three
was strongly criticized for its wording, tone and
format. Focus group participants said that they
would not read option three's message because of
their dislike for the card. Id. at 20-22. These find-
ings lead NHTSA to conclude that the text and
format and text for the message must be pre-
scribed so that the message itself does not
discourage purchasers from registering.

The motivational message has elements that
received general support in the National Analysts
study. Id. at 28. The text is based on option 1,
which received the most positive response in the
focus group testing. Id. at 15. However, the focus
groups found the text style of option 1 too hard
to read. They preferred a bold print, and that the
text be arranged in more of the "bullet" style of
option 2. The agency has revised the format in
accordance with those preferences.

The motivational message adopted today was
suggested by National Analysts in its February
1991 report. National Analysts made the sugges-
tion after evaluating the reaction of the focus
groups to the messages proposed as options in the
NPRM. Contrary to one commenter's belief,

PART 571; S 213— PRE-78

>fHTSA did not receive National Analysts'

^ suggestion for the "optimal" card until after the

/■ NPRM was developed. For that reason, the opti-

^ mal card was not among those proposed in the

NPRM. However. NHTSA placed the National

Analysts report in the public docket when the

NPRM was published, to make the card and the

report publicly available for review. See item

number three in the NPRM docket, 74-09-N20.

One commenter suggested that the card should
have a sentence in Spanish that directs the reader
to a resource for a translated version of the reg-
istration form. The effect of such a requirement
would be to require manufacturers to have forms
available in Spanish. The burden of such a
requirement on manufacturers does not appear
warranted, for the reasons discussed in the agen-
cy's November 20, 1990 denial of Texas's peti-
tion for rulemaking on requirinq Spanish instruc-
tions for child restraints. 55 FR 48262.

The focus group study showed that participants

reacted favorably to the idea of being assured by

the manufacturer that their names would not be

placed on a mailing list if they registered their

^ restraints. Although the agency is not restricting

M use of the names, it expects that manufacturers

^ will respect owners' preferences that their names

be kept separate from other customer lists.

This rule specifies a minimum size for the form
so that the part to be returned to the manufacturer
would be mailable as a postcard. That part of the
form, i.e., the postcard part, and the part of the
form to which the postcard is attached must both
be not less than 3 1/2 by 5 inches, and have a
thickness of not less than 0.007 inches and not
more than 0.0095 inches. These dimensions are
taken from postal regulations for cards mailable
without envelopes under first class postage.

2. Labeling requirements.

The NPRM proposed requirements to enable
owners of secondhand restraints to register. The
NPRM proposed that each restraint (other than
factory-installed built-in ones) must be perma-
nently labeled with information about the impor-
tance of registration, and instructions for tele-
phoning or mailing the necessary registration
information to the manufacturer. In addition, the
^ labeling would have to include infomiation about

" NHTSA's Auto Safety Hotline. The proposal also

included requirements that the registration

information be provided in the printed instructions
that accompany the restraint.

Several commenters said that the proposed
labeling is too long for the limited space available
on the restraint, or has words that imply that the
restraint is unsafe. NHTSA has shortened and
revised the message in response to those com-
ments. Some commenters suggested a new text
and format and other changes (e.g., using a tri-
angular warning symbol) that they believed would
more effectively urge the purchaser to register.
The agency reviewed the suggestions, but could
not conclude that the suggestions improved what
had been proposed, tested in the focus groups and
revised for this rule.

Fisher Price said that labeling the NHTSA Hot-
line number is unnecessary since the owner can
contact the manufacturer about recalls. The
agency disagrees. The Hotline number is nec-
essary to increase the public's awareness of that
recall information resource. Also, consumer com-
plaints to the Hotline have historically provided
NHTSA an important source of data on safety-
related defects. For that reason, the agency
requires vehicle manufacturers to include the Hot-
line in the vehicle owner's manual. See 49 CFR
Part 575. NHTSA is requiring the Hotline number
on each child restraint to ensure that the Hotline
can be readily used by each owner, even persons
owning secondhand restraints that are missing the
instructions.

This rule also requires manufacturers to provide
a mailing address and telephone number on the
label. The NPRM proposed either an address or
telephone number, but several commenters said
that both should be required to enable the owner
to contact the manufacturer in more than one
way. The CAS said that two companies (Virso/
Pride-Trimble and Century) recently changed their
toll-free telephone numbers which made it more
difficult for owners to contact the companies.
CAS stated, "Requiring both company address
and telephone number will help consumers get the
information they need." NHTSA is requiring both
an address and telephone number to make it
easier for a person to register.

PART 571; S 213— PRE-79

certain labeling and other requirements for built-
in restraint systems. 57 FR 870; January 9, 1992.
Any amendments that might ultimately be
adopted based on the January 1992 notice may
modify existing labeling requirements, including
the requirements adopted today.

3. Recordkeeping.

This rule establishes a new Part 588 in title 49,
CFR, to require manufacturers to establish a
record of registrants and maintain this record for
at least six years from the date of manufacture of
the seat. The record includes the name and mail-
ing address of each registrant, and the model
name or number and date of manufacture (month,
year) of the restraint.

The notice proposed an eight year period, but
comments were requested on whether a shorter
period, e.g., six years, should be required. Com-
menters were sharply divided about the record-
keeping requirement. Commenters suggested a
length of recordkeeping ranging from four to 10
years.

The agency is adopting a six year requirement
because NHTSA's records indicate that all
restraints recalled to date were recalled within six
years of the production date of the seat. (As
stated above, during 1981-1991, almost 18 million
child restraints were recalled. The average length
of time between date of production and date of
recall was about 28 months.) Some commenters
said that a 10 year requirement is warranted
because restraints more than 10 years old are still
being used. NHTSA does not agree that those
restraints, relatively few in number, justify record-
keeping for longer than six years, given the aver-
age age of recalled child restraints. NHTSA is
concerned that a period longer than six years
could impose an unwarranted recordkeeping bur-
den on manufacturers.

Costs.

The agency has revised its cost estimates for
this rulemaking. The NPRM and preliminary
regulatory evaluation (PRE) estimated that the
rule would have an average cost impact of $0.25
to $0.31 per seat. The estimated cost was $0.13
to $0.19 for high volume sales. $0.33 to $0.39 for
medium volume sales, and $0.93 to $0.99 for low
volume sales. The estimate included the cost for
providing and attaching the registration form,
labeling the restraint, recordkeeping, and provid-

ing postage. The ranges in the cost estimate were
based on a 20 percent to 40 percent return rate for
the forms.

Evenflo and Cosco disagreed with NHTSA's
cost estimates. Evenflo said that the estimated
cost for the low volume manufacturer was too
low. Evenflo also said that the agency's estimate
does not account for the cost doubling or tripling
for each level of the distribution chain through
which the restraint passes. "The ultimate cost to
the consumer (assuming that the cost is passed on
the consumer) will actually be three to ten times
the estimated $1 cost."

Cosco said that the agency's estimated costs
are too low. Cosco believed that the true manu-
facturing costs would be about $1.00 per seat.
"This cost translates into a retail price increase of
as much as 10 percent for the moderately priced
restraints and considerably more than that for
lower-priced booster seats and infant-only
restraints, which very well might result in lower
purchases of new car seats."

NHTSA contacted Evenflo and Cosco for
information about their cost estimates. Evenflo
provided information showing some of the basis
for its estimate. Cosco did not.

The agency used the information from Evenflo
to revise the cost estimates. The final regulatory
evaluation for this rule discusses the cost esti-
mates in detail. The evaluation, available in the
docket, explains that NHTSA did not agree with
some of Evenflo's assumptions about costs. For
example, the manufacturer's estimate for postage
costs was very high. However, Evenflo's informa-
tion enabled NHTSA to estimate that the rule will
cost $0.47 to $0.52 per restraint for high volume
manufacturers, and $0.95 to $1.26 for medium
volume manufacturers. These costs are based on
a manufacturing cost of $0.20 to $0.22 per
restraint for high volume manufacturers, and
$0.40 to $0.53 for medium volume manufacturers.
The agency determined the retail cost increase
based on Evenflo's information that the markup
from manufacturing cost to retail price is 2.37
times.

These costs were based on a 30 to 40 percent
return rate for the forms. The agency has decided
to change the estimated return rate for the child
restraint registration forms from 20 to 40 percent
in the NPRM, to 30 to 40 percent, since, as
explained above the percentage of the remedied
seats has increased.

PART 571; S 213— PRE-

Nomenclature unchanged.
^ The NPRM proposed a nomenclature change to
'■ Standard 213, to replace the term "child restraint
system" with "child safety seat." Two com-
menters supported the change. About nine com-
menters ranging from manufacturers to research-
ers to safety groups adamantly opposed it. Many
of the commenters opposing the change said the
term child safety seat could mislead consumers
into believing that the device will provide
absolute protection in a crash. Manufacturers said
that such an expectation of absolute protection
could result in severe liability implications for
them in the event a child is injured or killed in
the device. Some commenters said that the term
child safety seat is not descriptive enough to
make clear that it covers devices such as car beds,
vests and harnesses. As a result, the term would
be confusing in Standard 213.

By proposing the nomenclature change, the
agency sought to get consumers to better under-
stand the importance of the seat to the child's
safety in the automobile and on aircraft. NHTSA
did not intend to change manufacturers' potential
^ legal liability, nor did NHTSA intend to unsettle
B or confuse the current understanding concerning
which devices are included within the term "child
restraint systems." While the effectiveness of
child restraints is beyond question in view of data
indicating they reduce a child's risk of death or
serious injury by 70 percent, the agency agrees
that the proposed nomenclature change could be
confusing, and defers to commenters' assessment
that the change might have unintended, undesir-
able effects on manufacturers' legal liability.
NHTSA is therefore retaining the term "child
restraint system" in Standard 213.

The final rule does not have any retroactive
effect. Under section 103(d) of the National Traf-
fic and Motor Vehicle Safety Act (15 U.S.C.
1392(d)), whenever a Federal motor vehicle safety
standard is in effect, a state may not adopt or
maintain a safety standard applicable to the same
aspect of performance which is not identical to
the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending or
revoking Federal motor vehicle safety standards.
I That section does not require submission of a
petition for reconsideration or other administrative
proceedings before parties may file suit in court.

In consideration of the foregoing, NHTSA
amends 49 CFR Part 571 as set forth below:

1. S4 is amended by adding the following defi-
nition:

Factory-installed built-in child restraint system
means a built-in child restraint system that was
installed in a motor vehicle at the time of its
delivery to a dealer or distributor for distribution.

2. S5.5.1 is revised to read as follows:

55.5.1 Each add-on child restraint system shall be
permanently labeled with the information specified
in S5.5.2(a) through (m).

3. S5.5.2 is amended by replacing the reference
to paragraph "(1)" in the introductory paragraph
with a reference to paragraph "(m)," by
redesignating the existing text in paragraph (m) as
paragraph (n), and by adding new paragraph (m),
to read as follows:

55.5.2 The information specified in paragraphs (a)
through (m) of this section shall be stated in the
English language and lettered in letters and num-
bers that are not smaller than 10 point type and
are on a contrasting background.

(m) The following statement, inserting an
address and telephone number: "Child restraints
could be recalled for safety reasons. You must
register this restraint to be reached in a recall.
Send your name, address and the restraint's model
number and manufacturing date to {insert
address) or call {insert telephone number). For
recall information, call the U.S. Government's
Auto Safety Hotline at 1-800-424-9393 (202-366-
0123 in D.C. area)."

(n) Child restraint systems that are certified as
complying with the provisions of section S8 shall
be labeled with the statement "THIS
RESTRAINT IS CERTIFIED FOR USE IN
MOTOR VEHICLES AND AIRCRAFT." This
statement shall be in red lettering, and shall be
placed after the certification statement required by
paragraph (e) of this section.

4. S5.5.4 is revised to read as follows:

S5.5.4 Each built-in child restraint system shall be
permanently labeled with the information specified
in S5.5.5(a) through (j) so that it is visible when

PART 571; S 213— PRE-81

the seat is activated for use as specified in S5.6.2.
and, except a factory-installed built-in restraint,
shall be permanently labeled with the information
specified in S5.5.5(k).

5. S5.5.5 is amended by revising the introduc-
tory text and adding paragraph (k) to read as fol-
lows:

S5.5.5 The information specified in paragraphs (a)
through (k) of this section shall be stated in the
English language and lettered in letters and num-
bers that are not smaller than 10-point type and
are on a contrasting background. The information
specified in paragraphs (a) through (j) shall be
printed in the vehicle's owner's manual.

(k) The following statement, inserting an
address and telephone number: "Child restraints
could be recalled for safety reasons. You must
register this restraint to be reached in a recall.
Send your name, address and the restraint's model
number and manufacturing date to (insert
address) or call (insert telephone number). For
recall information, call the U.S. Government's
Auto Safety Hotline at 1-800-424-9393 (202-366-
0123 in D.C. area)."

6. S5.6 would be amended by adding para-
graph S5.6.1.7 and S5. 6.2.2, to read as follows:

S5.6 Printed instructions for proper use.

S5.6.1.7 The instructions shall include the follow-
ing statement, inserting an address and telephone
number: "Child restraints could be recalled for
safety reasons. You must register this restraint to
be reached in a recall. Send your name, address
and the restraint's model number and manufactur-
ing date to (insert address) or call (insert tele-
phone number). For recall information, call the
U.S. Government's Auto Safety Hotline at 1-800-
424-9393 (202-366-0123 in D.C. area)."

6.2.2 The instructions for each built-in child
restraint system, except a factory-installed
restraint, shall include the following statement,
inserting an address and telephone number:
"Child restraints could be recalled for safety rea-
sons. You must register this restraint to be reached
in a recall. Send your name, address and the
restraint's model number and manufacturing date
to (insert address) or call (insert telephone num-
ber). For recall information, call the U.S. Govern-
ment's Auto Safety Hotline at 1-800-424-9393
(202-366-0123 in D.C. area)."

* * * *

7. A new paragraph S5.8 is added to 571.213
to read as follows:

S5.8 Infomiation requirements — registration form.

(a) Each child restraint system, except a fac-
tory-installed built-in restraint system, shall have
a registration foiTn attached to any surface of the
restraint that contacts the dummy when the
dummy is positioned in the system in accordance
with S6. 1.2 of Standard 213.

(b) Each form shall:

(1) Consist of a postcard that is attached at
a perforation to an informational card;

(2) Conform in size, content and format to
Figures 9a and 9b; and

(3) Have a thickness of at least 0.007 inches
and not more than 0.0095 inches.

(c) Each postcard shall provide the model name
or number anddate of manufacture (month, year)
of the child restraint system to which the form is
attached, shall contain space for the purchaser to
record his or her name and mailing address, shall
be addressed to the manufacturer, and shall be
postage paid. No other infonnation shall appear
on the postcard, except identifying information
that distinguishes a particular child restraint sys-
tem from other systems of that model name or
number may be preprinted in the shaded area of
the postcard, as shown in figure 9a.

Figures 9a and 9b are added to 571.213.

57 F.R. 41428
Septmber 10, 1992

PART 571; S 213— PRE-82

-► 5" minimum —

FOR YOUR CHILD'S CONTINUED SAFETY

Please take a few moments to promptly fill out and return the
attached card.

Although child restraint systems undergo testing and evaluation,
it is possible that a child restraint could be recalled.

In case of recall, we can reach you only if we have your name
and address, so please send in the card to be on our recall list

Please fill this card out and mail it NOW,
while you are thinking about it.

it's already addressed and we've paid the postage.

Tear off and mail this part

Consumer: Just fin in your name and address.

Your name

Your street address

City stale Zip Code

CHILD RESTRAINT REGISTRATION CARD

RESTRAINT MODEL XXX
SERIAL NUMBER YYYY
MANUFACTURED ZZ-ZZ-19ZZ

Preprinted

message to
.^consumer: bold
'typeface, caps

and lower case

minimum 12 point

type.

FOLD / PERFORATION

Minimum 10%
screen tint.

Preprinted or
stamped child
safety seat
model name or
number and date
of manufacture.

Figure 9a— Registration Form for Child Systems— Product Identification Number and Purchaser

Information Side.

PART 571; S 213— PRE-83

3.5"
minimum

IMPORTANT

In case of a recall, we can reach you only if we
have your name and address. You MUST send in
the attached card to be on our recall list

We've already paid the postage.
Do it today.

NO POSTAGE

NECESSARY

IF MAILED

IN THE

UNITED STATES

3,5"
minimum

MANUFACTURER
POST OFFICE BOX 0000
ANYTOWN, ST 12345-6789

Block letters
(sans serif)— Bold
minimum 48 point
type, caps.

Minimum 10°/
screen tint

Preprinted
message to
consumer; bold
typeface, caps
and lower case
minimum 12 point
type.

FOLD I PERFORA TION

Preprinted or
stamped name
and address of
manufacturer or
itsi

Figure 9b— Registration Form for Child Restraint Systems— Address Side.

PART 571; S 213— PRE-84

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE
SAFETY STANDARD NO. 213

Child Restraint Systems

(Docket No. 74-09; Notice 27)
RIN: 2127-AD45

ACTION: Final rule.

SUMMARY: This rule amends Federal Motor
Vehicle Safety Standard 213. Child Restraint Sys-
tems, to require add-on child restraints to meet the
requirements of the standard at each of the angles
to which the seat back can be adjusted and at each
of the restraint belt routing positions. This amend-
ment improves safety by removing the possibility
that a child restraint can be designed to transport
a child in a motor vehicle or aircraft while the
restraint is adjusted to a position in which the
restraint would not comply with the standard.

DATES: The amendment is effective on March 9,
1993.

SUPPLEMENTARY INFORMATION: This rule
amends S5 of Standard 213, Child Restraint Sys-
tems, to expand the requirements for child
restraint systems manufactured for use in motor
vehicles, and motor vehicles and aircraft.

The requirements are expanded to apply to pre-
viously-excluded adjustment positions on child
restraints. Child restraint systems typically have
more than one seat back angle adjustment posi-
tion and a number of restraint belt routing posi-
tions. Under the standard before this amendment,
adjustment positions could be excluded from the
excursion (S5.1.3) and seat inversion (S8.2)
requirements of the standard if the manufacturer
warned that the positions were not for use in
motor vehicles or aircraft. This rule eliminates
that exclusion of adjustment positions, regardless
of whether the manufacturer provides a warning.

This rule also removes the related provisions
(S5.5.2(i), S8.1) that required manufacturers of
restraints with excluded adjustment positions to
identify those positions on labels attached to the
restraints. This rule also amends the conditions
for the dynamic systems test and the inversion

test to clarify the effect of removing these provi-
sions.

The proposal for this rule was published on
August 12, 1991 (56 FR 38105). NHTSA began
this action in response to a petition for rule-
making from Consumer Action (CA) and the
Center for Auto Safety (CAS).

Background

This rulemaking highlights the relationship
between the test procedures specified in Standard
213 and the performance required of a child
restraint system. The National Traffic and Motor
Vehicle Safety Act requires child restraint manu-
facturers to certify each restraint as complying
with Standard 213. NHTSA checks the validity of
the certification by evaluating the restraint's
performance when tested in accordance with the
procedures specified in the standard (S6, S8).
Generally, the procedures for the dynamic sled
and seat inversion tests specify that the restraint
be installed on a simulated car or aircraft seat "in
accordance with the manufacturer's instructions"
provided to the consumer. (However, the proce-
dures for the dynamic sled test require that most
restraints must be secured using only the standard
vehicle lap belt. See, S6. 1.2. 1.1 (a)) The proce-
dures also specify that the test dummy used to
test the restraint is positioned "according to the
instructions for child positioning" provided by
the manufacturer to the consumer. (See. e.g.,
S6. 1.2.3.1, 6.1.2.3.2 and 6.1.2.3.3.) The installa-
tion instructions must provide a narrative discus-
sion and diagrams to facilitate installing the
restraint in motor vehicles or aircraft, positioning
a child in the restraint and adjusting the restraint
to fit the child (S5.6.1 and S8.1).

Each adjustment position of a child restraint is
currently subject to dynamic testing unless the
restraints manufacturer does not intend that posi-
tion to be used in motor vehicles or aircraft and

PART 571; S 213 PRE-85

expressly states that intent on a label attached to
the restraint. If the position is not intended to be
so used, it is excluded from the standard's occu-
pant excursion (S5.1.3) and inversion (S8.2)
requirements. The purpose of the excursion and
inversion requirements is to ensure that the child
occupant is retained within the system in a crash.

Consumer Action and CAS requested that
NHTSA amend Standard 213 by removing the
provision, S5.5.2(i), which requires manufacturers
to warn consumers, by way of a warning label on
the restraint, against using an adjustment position
in a vehicle if the manufacturer deems the posi-
tion is unsuitable for such use. The petitioners
believed that the S5.5.2(i) warning label is
insufficient to ensure that a child restraint system
will not be used in the restricted positions in a
motor vehicle. It appeared that the basis for the
petition was the petitioners' belief that warning
labels are generally ineffective.

NHTSA issued a notice of proposed rule-
making (NPRM) to further consider the issue of
restricted adjustment positions. NHTSA did not
agree with the petitioners that warning labels are
generally insufficient to produce desired behav-
iors. However, the agency was concerned about
positions that are unsuitable for vehicle use, yet
are made a part of a child restraint system for no
reason that outweighs the likelihood that the seat
will be misused and the risk to safety unaccept-
ably increased. (56 FR at 38106.)

NHTSA developed a proposal to achieve the
purpose of the requested amendment. With regard
to restraints for motor vehicles, NHTSA proposed
to amend S5.1.3, Occupant excursion, to remove
the provision that excludes the restricted positions
from the excursion requirement. Since the exclu-
sion would be removed, NHTSA also proposed to
remove S5.5.2(i), the labeling provision for
restricting a position. To make clear the effect of
these amendments, NHTSA proposed to amend
S5 to require each restraint to "meet the require-
ments in [S5] at all adjustment positions (includ-
ing, but not limited to each seat back angle
adjustment position and each restraint belt anchor-
age and routing position), when tested in accord-
ance with S6.1" of Standard 213.

With regard to restraints for aircraft, the NPRM
proposed similar amendments. The NPRM pro-
posed to remove the provision in Standard 213
that excludes restricted adjustment positions from

the inversion test requirement (S8.2) and to
remove the warning label requirement in S8.1. ^

In issuing the NPRM, NHTSA believed that jj|
most manufacturers had ceased designing child
restraints with adjustment positions not intended
for motor vehicle and aircraft use. However, the
agency tentatively concluded the amendments
were needed to ensure that no restricted position
would be included in future restraint systems. Id.

Comments on the NPRM
NHTSA received comments from CAS, Advo-
cates for Highway and Auto Safety, Cosco, Ford
Motor Company, and the University of Michigan.
These entities generally supported the NPRM,
with comments relating to particular issues raised
by the proposal.

EjfectofSS

Cosco and the University of Michigan sug-
gested that the language of the proposed amend-
ment to S5 was unclear and overbroad. Cosco
said that a number of adjustment positions on its
child restraints could be unintentionally affected
by the proposed S5, and that convertible restraints
might be especially affected. (Convertible
restraints are restraints designed for use by both ^

infants and toddlers. For most convertible
restraints, certain restraint adjustment positions
are designed for infants only, while other posi-
tions are suitable for toddlers only.) Emphasizinq
that the NPRM stated convertible restraints serve
a safety need, Cosco argued that their manufac-
ture should be not prohibited.

Cosco gave several examples of how it
believed that the proposed language of S5 would
create uncertainty about the permissibility of cer-
tain adjustment positions on convertible restraints.
Cosco said that its "Dream Ride" restraint is a
"car seat/car bed with an upright, rear-facing
position and fully reclined, side-facing position."
The instructions for the restraint state that it
should not be used in a front-to-back position
when fully reclined, i.e., placed in a vehicle so
that its and the vehicle's longitudinal axes are
parallel.

The commenter believed that the proposed lan-
guage would subject the fully reclined position to
Standard 213 requirements in the front-to-back
position on the standard seat assembly. Cosco |

suggested that S5 should expressly pennit manu-
facturers to "designate ... that certain weights and

PART 571: S 213 PRE-

seating positions are not acceptable under certain
conditions, as long as there are no adjustment
^ positions available which cannot be used in motor
" vehicles under any conditions."

To address Cosco's concerns, NHTSA has
made several changes. The agency has revised the
amendment to S5. The amendment retains the
existing statement in S5 about child restraint
requirements:

Each child restraint system certified for use
in motor vehicles shall meet the requirements
in this section when, as specified, tested in
accordance with S6.1.
In addition, the agency is adding a statement
specifying that each add-on system shall meet the
requirements of S5 at each of the restraint's seat
back angle adjustment positions and restraint belt
routing positions, when the restraint is oriented in
the direction recommended for use (e.g., forward,
rearward or laterally) pursuant to S5.6, and used
with the test dummy specified in S7 of the stand-
ard.

Under the first sentence in S5, the orientation
and adjustment of a child restraint for compliance
testing purposes is determined based upon the
^ instructions given by manufacturers to consumers
i regarding the installation and use of that restraint.
The second sentence qualifies the first sentence
by limiting the extent to which a manufacturer's
instructions affect how and to what extent a child
restraint is subject to testing under the standard.
Under the second sentence, regardless of the
manufacturer's instructions, a child restraint is
subject to testing in all seat back angles and belt
routing positions. However, a manufacturer's
instructions about a matter such as restraint ori-
entation will still affect compliance testing. For
example, if a manufacturer's instructions state that
a car bed is to be installed side-to-side (per-
pendicular to the vehicle's longitudinal axis), but
not front-to-back (parallel to that axis), the car
bed will be subject to testing in the side-to- side
orientation only.

It does not appear, however, that the originally
proposed amendment to S5 would have caused
the seat positioning problems Cosco described for
its Dream Ride restraint. The proposed text
retained the present provision in S5 that restraints
are "tested in accordance with S6.1," the section
^ in the standard that specifies the test conditions
W and procedures for the dynamic systems test.
Under S6.1, a restraint is installed on a simulated

vehicle seat in accordance with the manufactur-
er's instructions. A restraint that is designed to be
adjusted to different configurations for different
child weights is oriented forward, rearward or lat-
erally, depending on the manufacturer's instruc-
tions for using the restraint.

The University of Michigan (UM) suggested S5
would be clearer if it stated: "Each child restraint
system certified for use in motor vehicles shall
meet the requirements in this section at each
adjustment position (...) in at least one type of
vehicle (ground or aircraft) when tested in accord-
ance with the procedures of S6.1 for at least one
specified range of child weight." As amended
today, S5 is similar to UM's suggested text. How-
ever, the agency has not adopted the "ground or
aircraft" language suggested by the commenter.
When a manufacturer certifies its restraint as
complying with the requirements for restraints for
aircraft, the manufacturer states: "THIS
RESTRAINT IS CERTIFIED FOR USE IN
MOTOR VEHICLES AND AIRCRAFT."
(S5.5.2(m); emphasis added.) An adjustment posi-
tion that meets Standard 213 for aircraft use but
not for vehicle use would not be acceptable under
the standard.

Othei- amendments
This rule makes conforming changes to the test
procedures for the excursion and inversion
requirements. Currently, the test dummy used to
test to these requirements is positioned in the
restraint according to the manufacmrer's instruc-
tions for child positioning. Under today's amend-
ment, each of the restraint's seat back angles and
belt routing positions will be subject to testing,
notwithstanding the manufacturer's instructions
not to use those adjustment positions in vehicles
or aircraft.

Aircraft use

Cosco commented that the proposed amend-
ment to the requirements for restraints certified
for aircraft use would have a negative impact on
its Dream Ride restraint. NHTSA disagrees.

Cosco said it currently informs the consumer
that the restraint should be used on aircraft only
in the partially upright (rear-facing) position.
Cosco said that it does not recommend the fully
reclined position on aircraft since two aircraft
seats are needed to accommodate the restraint in
that adjustment position and consumers are
unlikely to purchase those seats. Cosco indicated

PART 571; S 213 PRE-87

that the Dream Ride perfonns adequately in the
car bed position, if the two aircraft seats are used.
The commenter was concerned that it would have
to eliminate the fully reclined position because
the position is one that is not intended for use in
aircraft.

NHTSA does not seek to have Cosco eliminate
the fully reclined position on its restraint, or
remove the Dream Ride from the models of
restraints certified for both motor vehicles and
aircraft. Safety is furthered by the availability of
restraints manufactured for both vehicles and air-
craft.

NHTSA does seek to ensure through today's
amendment to the aircraft requirements that each
seat back angle and belt routing position in
restraints manufactured for both vehicles and air-
craft passes the inversion requirement when tested
according to the procedures in the standard.
Cosco indicated that the Dream Ride, fully
reclined, would pass the inversion test while
fully-reclined and positioned crosswise, on two
aircraft seats. If that is the case, the restraint
already complies with the standard's amended air-
craft requirements. As long as the restraint passes
while fully reclined and positioned crosswise, the
existence of that adjustment position does not
prohibit Cosco from manufacturing and selling
that child restraint. Further, nothing prohibits
Cosco from recommending in its information to
consumers that the seat not be used in that ori-
entation on aircraft. Thus, the restraint must meet
the inversion test in all of its back angles and belt
routing positions. For example, the Dream Ride
could be tested fully reclined with the six-month-
old dummy while positioned crosswise, on two
aircraft seats, even if Cosco recommends the fully
reclined position not be used on aircraft.

Built-in restraint systems
Ford said the proposed amendments to S5
could complicate testing of built-in child restraints
that form part of a reclining vehicle seat. Ford
stated:

Built-in child restraints can be installed in
vehicle seats that can be adjusted to positions
that are not intended for use while the vehicle
is moving. For example, many vehicle seats
can be reclined to allow weary drivers and pas-
sengers to rest at highway rest areas.
Ford suggested that the proposed amendment
expressly apply to add-on restraints only. The

commenter believed such application was
intended by the agency, since no mention was
made in the preamble for the NPRM about built-
in restraints.

Ford also asked about an apparent discrepancy
between the effect of the proposed S5 on built-in
restraints and the specified test conditions (S6.1.1)
for testing the restraints. The proposed S5 would
have required built-in restraints to meet the stand-
ard's requirements "at all adjustment positions"
when tested in accordance with the conditions and
procedures of S6.1. However, under S6.1, if a
specific vehicle is used (the second of two stand-
ard test devices that can be used, at the manufac-
turer's option, to test a built-in system), a built-
in system is tested with the vehicle seat "in the
manufacturer's nominal design riding position."
Stated differently, S6. 1 provides for testing only
one adjustment position.

Ford is correct that the agency intended only to
address add-on systems in this rulemaking action.
NHTSA did not consider how the proposed
amendment would affect adjustment positions on
built-in seats. For those seats, a reclining vehicle
seat back may also be the seat back of a child
restraint built into the vehicle seat.

A built-in system that is part of a seat with a
reclining seat back would probably fail to meet
the standard if the seat back were reclined and if
today's rule applied to it. Such an amendment
could have required some redesigning of seats.
The agency is uncertain whether there is suffi-
cient reason to disallow the reclining feature.
Reclining seats let weary drivers and passengers
rest at highway rest areas (as discussed by Ford
in its comment). Indeed, NHTSA has observed
that some reclining seat backs in vans recline all
the way down to the horizontal position so as to
create a sleeping surface stretching from the rear
of the third seating surface to the front of the sec-
ond seating surface. Reclining seats also provide
for easier loading of the vehicle.

Use of a built-in restraint when the vehicle seat
back is reclined at a sharp angle would be
undesirable. However, until the agency learns that
vehicles being driven with children in such
reclined positions occurs frequently enough to
become a significant problem, the relative merits
of the reclining vehicle seat need not be further
addressed. There is sufficient justification for the
reclinability of such seats to warrant their exclu-
sion from today's S5 amendments. However,

PART 571; S 213 PRE-88

NHTSA recommends that manufacturers warn
consumers against using an adjustment position
on a built-in restraint while the vehicle is in
motion if the position cannot provide adequate
protection.

In response to an issue raised by Ford in its
comment, today's rule adopts a technical amend-
ment to the standard's test conditions for built-in
restraints. As stated above, Standard 213 permits
manufacturers the option of choosing to test a
buih-in system with the specific vehicle shell or
the specific vehicle. (S6. 1.1. 1(a).) Ford pointed
out that the conditions under which a built-in sys-
tem is tested using the shell are inconsistent with
those under which the vehicle is tested.

The conditions are specified in much greater
details for the vehicle test than the shell test.
Some of the conditions are appropriate for the
vehicle and not for the shell, e.g., vehicle loading
specifications. However, many of the conditions
specified in the vehicle test are relevant for the
shell test but are not specified for the latter. For
example, conditions for the longitudinal and verti-
cal seat positioning, and seat back adjustment
position, are relevant yet unspecified.

As a practical matter, the lack of specifications
is inconsequential. The test procedures for built-
in restraints direct NHTSA to '"activate the
restraint in the specific vehicle shell or the spe-
cific vehicle, in accordance with the manufactur-
er's instructions provided in the vehicle owner's
manual in accordance with S5.6.2." (See
S6. 1.2. 1.1 and S6.1.2.I.2.) Under these instruc-
tions, the vehicle seat that contains the built-in
child restraint generally would be adjusted as the
manufacturer directs, for both the vehicle and the
shell tests.

This rule makes the test conditions for the
vehicle and shell tests consistent, in response to
Ford's request that the conditions be clarified.
The amendment is merely technical; the agency
believes there will be no changes in the manner
in which built-in restraints are tested.

Other comments
NHTSA stated in the NPRM that the agency
conducted an informal survey of 15 restraint sys-
tems, and did not find any currently being manu-
factured that is labeled with the S5.5.2(i) warning.
56 FR at 38106. Both CAS and Advocates for
Highway-and Auto Safety (Advocates) said that
NHTSA should survey all child seat manufactur-

ers to determine whether restraints are being sold
with restricted adjustment positions.

NHTSA does not believe an additional survey
is necessary. Child restraint manufacturers did not
question the validity of the agency's survey,
except to point out the issue about built-in
restraints, discussed above. An additional survey
is unlikely to yield knowledge more useful than
the information that the agency already possesses.

CAS and Advocates commented also on issues
that were outside the scope of the rulemaking
proposal. They concurred with NHTSA that
convertible restraints should continue to be avail-
able to consumers. However, both organizations
suggested further large-scale testing of the
restraints by NHTSA. CAS said the agency
should determine whether the seats "provide ade-
quate protection in any adjustment position."
Advocates urged NHTSA to conduct tests on
whether convertible seats are being properly used
by the consumer. CAS and Advocates also com-
mented on improving Standard 213's labeling
requirements. Both said the agency should guide
the industry toward developing improved
consumer information on the appropriate use of a
restraint system.

NHTSA regards these comments as suggestions
for future rulemaking. The agency has placed
copies of the comments in NHTSA docket 74-09-
N21, which relates to planned research and pos-
sible upgrades to Standard 213.

Typographical correction
No comments were received on the proposed
correction of S5.3.1. The correction is made in
this rule.

Concurrent amendments

Readers should note that Standard 213's label-
ing requirements are further amended by a final
rule published elsewhere in today's edition of the
Federal Register. That rulemaking relates to an
owner registration requirement for child restraint
systems. In addition, NHTSA published an
NPRM to amend certain labeling and other
requirements for built-in restraint systems. 57 FR
870; January 9, 1992. Any amendments that
might ultimately be adopted based on the January
1992 notice may modify existing labeling require-
ments, including the requirements adopted today.

This final rule does not have any retroactive
effect. Under § 103(d) of the National Traffic and

PART 571:8 213 PRE-89

Motor Vehicle Safety Act (15 U.S.C. 1392(d)),
whenever a Federal motor vehicle safety standard
is in effect, a state may not adopt or maintain a
safety standard applicable to the same aspect of
performance which is not identical to the Federal
standard. Section 105 of the Act (15 U.S.C. 1394)
sets forth a procedure for judicial review of final
rules establishing, amending or revoking Federal
motor vehicle safety standards. That section does
not require submission of a petition for
reconsideration or other administrative proceed-
ings before parties may file suit in court.

In consideration of the foregoing, NHTSA
amends 49 CFR part 57 1 as set forth below.

1. The authority citation for part 571 continues
to read as follows:

Authority. 15 U.S.C. 1392, 1401, 1403, 1407;
delegation of authority at 49 CFR 1.50. §571.213
[Amended]

2. The introductory text of S5 is revised to read
as follows:

S5 Requirements for child restraint systems
certified for use in motor vehicles. Each child
restraint system certified for use in motor vehicles
shall meet the requirements in this section when,
as specified, tested in accordance with S6.1 and
this paragraph. Each add-on system shall meet the
requirements at each of the restraint's seat back
angle adjustment positions and restraint belt rout-
ing positions, when the restraint is oriented in the
direction recommended by the manufacturer (e.g.,
forward, rearward or laterally) pursuant to S5.6,
and tested with the test dummy specified in S7.

3. S5.1.3 is revised to read as follows:

S5.1.3 Occupant excursion. When tested in
accordance with S6.1, each child restraint system
shall meet the applicable excursion limit require-
ments specified in S5. 1.3.1- S5.1.3.3.

4. S5.3.1 is revised to read as follows:

S5.3.1 Each add-on child restraint system shall
have no means designed for attaching the system
to a vehicle seat cushion or vehicle seat back and
no component (except belts) that is designed to be
inserted between the vehicle seat cushion and
vehicle seat back.

5. S5.5.2(i) is removed and reserved.

6. S5.5.5(g) is revised to read as follows:

(g) The statement specified in paragraph (1), _

and if appropriate, the statement in paragraph (2): £m

(1) WARNING! FAILURE TO FOLLOW THE
MANUFACTURER'S INSTRUCTIONS ON
THE USE OF THIS CHILD RESTRAINT SYS-
TEM CAN RESULT IN YOUR CHILD STRIK-
ING THE VEHICLE'S INTERIOR DURING A
SUDDEN STOP OR CRASH.

(2) In the case of each built-in child restraint
system which is not intended for use in the motor
vehicle at certain adjustment positions, the follow-
ing statement, inserting the manufacturer's adjust-
ment restrictions.

DO NOT USE THE ADJUSTMENT

POSITION(S) OF THIS CHILD RESTRAINT
WHILE THE VEHICLE IS IN MOTION.

7. S6. 1.1. 1(a) through the introductory text of
S6. 1.1. 1(c) is revised to read as follows:

S6. 1.1. 1(a) The test device for add-on restraint
systems is the standard seat assembly specified in
S7.3. The assembly is mounted on a dynamic test
platform so that the center SORL of the seat is fl
parallel to the direction of the test platform travel
and so that movement between the base of the
assembly and the platform is prevented.

(b) The test device for built-in child restraint
systems is either the specific vehicle shell or the
specific vehicle.

(l)(i) The specific vehicle shell, if selected for
testing, is mounted on a dynamic test platform so
that the longitudinal center line of the shell is par-
allel to the direction of the test platform travel
and so that movement between the base of the
shell and the platform is prevented. Adjustable
seats are in the adjustment position midway
between the forwardmost and rearmost positions,
and if separately adjustable in a vertical direction,
are at the lowest position. If an adjustment posi-
tion does not exist midway between the
forwardmost and rearmost position, the closest
adjustment position to the rear of the midpoint is
used. Adjustable seat backs are in the manufactur-
er's nominal design riding position. If such a
position is not specified, the seat back is posi-
tioned so that the longitudinal center line of the ^
child test dummy's neck is vertical, and if an W
instrumented test dummy is used, the acceler-

PART 571; S 213 PRE-90

ometer surfaces in the dummy's head and thorax,
as positioned in the vehicle, are horizontal. If the
vehicle seat is equipped with adjustable head
restraints, each is adjusted to its highest adjust-
ment position.

(ii) The platform is instrumented with an accel-
erometer and data processing system having a fre-
quency response of 60 Hz channel class as speci-
fied in Society of Automotive Engineers Rec-
ommended Practice J211 JUN80 "Instrumentation
for Impact Tests." The accelerometer sensitive
axis is parallel to the direction of test platform
travel.

(2) For built-in child restraint systems, an alter-
nate test device is the specific vehicle into which
the built-in system is fabricated. The following
test conditions apply to this alternate test device.

*****
In S6.1.1, S6.1.1.5 is added to read as fol-

lows:

S6. 1.1.5 In the case of add-on child restraint
systems, the restraint shall meet the requirements
of S5 at each of its seat back angle adjustment
positions and restraint belt routing positions, when
the restraint is oriented in the direction rec-
ommended by the manufacturer (e.g., forward,
rearward or laterally) pursuant to S5.6, and tested
with the test dummy specified in S7.
9. S8.1 is revised to read as follows:
S8.1 Installation instructions. Each child
restraint system manufactured for use in aircraft

shall be accompanied by printed instructions in
English that provide a step-by-step procedure,
including diagrams, for installing the system in
aircraft passenger seats, securing a child in the
system when it is installed in aircraft, and adjust-
ing the system to fit the child.

10. S8.2 is revised to read as follows:
S8.2 Inversion test. When tested in accordance
with S8.2.1 through S8.2.5, each child restraint
system manufactured for use in aircraft shall meet
the requirements of S8.2.1 through S8.2.6. The
manufacturer may, at its option, use any seat
which is a representative aircraft passenger seat
within the meaning of S4. Each system shall meet
the requirements at each of the restraint's seat
back angle adjustment positions and restraint belt
routing positions, when the restraint is oriented in
the direction recommended by the manufacturer
(e.g., facing forward, rearward or laterally) pursu-
ant to S8.1, and tested with the test dummy speci-
fied in S7. If the manufacturer recommendations
do not include instructions for orienting the
restraint in aircraft when the restraint seat back
angle is adjusted to any position, position the
restraint on the aircraft seat by following the
instructions (provided in accordance with S5.6)
for orienting the restraint in motor vehicles.
Issued on: September 4, 1992.

Howard M. Smolkin
Executive Director

57 F.R. 41423
September 10, 1992

PART 571 :S 213 PRE-91

FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 213

Child Restraint Systems, Seat Belt Assemblies, and Anchorages

(Docket No. 74-9; Notice 26)
RIM: 2127-AD46

51. Scope. This standard specifies requirements
for child restraint systems used in motor vehicles
and aircraft.

52. Purpose. The purpose of this standard is to
reduce the number of children killed or injured in
motor vehicle crashes and in aircraft.

53. Application. This standard applies to child
restraint systems for use in motor vehicles and air-
craft.

54. Definitions. Add-on child restraint system
means any portable child restraint system.

Booster seat means a child restraint which con-
sists of only a seating platform that does not
extend up to provide a cushion for the child's
back or head.

Built-in child restraint system means any child
restraint system which is an integral part of a pas-
senger car.

Car bed means a child restraint system
designed to restrain or position a child in the
supine or prone position on a continuous flat sur-
face.

Child restraint system means any device,
except Type I or Type II seat belts, designed for
use in a motor vehicle or aircraft to restrain, seat,
or position children who weigh 50 pounds or less.

Contactable swface means any child restraint
system surface (other than that of a belt, belt
buckle, or belt adjustment hardware) that may
contact any part of the head or torso of the appro-
priate test dummy, specified in S7, when a child
restraint system is tested in accordance with S6.1.
\_Factory-installed built-in child restraint system
means a built-in child restraint system that was
installed in a motor vehicle at the time of its
delivery to a dealer or distributor for distribution.
(57 F.R. 41428— September 10, 1992. Effective:
March 9, 1993)]

Representative aircraft passenger seat means
either a Federal Aviation Administration approved
production aircraft passenger seat or a simulated
aircraft passenger seat conforming to Figure 6.

Seat orientation reference line or SOR means
the horizontal line through Point Z as illustrated
in Figure lA.

SORL— SEAT ORIENTATION REFERENCE LINE (HORIZONTAL)

Figure 1 A— SORL Location on the Standard
Seat

Specific vehicle shell means the actual vehicle
model part into which the built-in child restraint
system is fabricated, including the complete
surroundings of the built-in system. If the built-
in child restraint system is manufactured as part
of the rear seat, these surroundings include the
back of the front seat, the interior rear side door
panels and trim, the rear seat, the floor pan, the
B and C pillars, and the ceiling. If the built-in
system is manufactured as part of the front seat,
these surroundings include the dashboard; the
steering wheel, column, and attached levers and
knobs; the "A" pillars; any levers and knobs
installed in the floor or on a console; the interior
front side door panels and trim; the front seat; the
floor pan; and the ceiling.

Torso means the portion of the body of a
seated anthropomorphic test dummy, excluding
the thighs, that lies between the top of the child

PART 571; S 213-1

(Rev. 9/10/92)

restraint system seating surface and the top of the
shoulders of the test dummy.

S5. Requirements for child restraint systems
certified for use in motor vehicles. [Each child
restraint system certified for use in motor vehicles
shall meet the requirements in this section when,
as specified, tested in accordance with S6.1. and
this paragraph. Each add-on system shall meet the
requirements at each of the restraint's seat back
angle adjustment positions and restraint belt rout-
ing positions, when the restraint is oriented in the
direction recommended by the manufacturer (e.g.,
forward, rearward or laterally) pursuant to S5.6,
and tested with the test dummy specified in S7.
(57 F.R. 41423— September 10, 1992. Effective:
March 9, 1993)]

S5.1 Dynamic performance.

55.1.1 Child restraint system integrity. When
tested in accordance with S6.1, each child restraint
system shall;

(a) Exhibit no complete separation of any load
bearing structural element and no partial separa-
tion exposing either surfaces with a radius of less
than '/4 inch or surfaces with protrusions greater
than Vs inch above the immediate adjacent
surrounding contactable surface of any structural
element of the system;

(b) If adjustable to different positions, remain
in the same adjustment position during the testing
as it was immediately before the testing; and

(c) If a front facing child restraint system, not
allow the angle between the system's back sup-
port surfaces for the child and the system's seat-
ing surface to be less than 45 degrees at the
completion of the test.

55.1.2 Injury criteria. When tested in accord-
ance with S6.1, each child restraint system that, in
accordance with S5.5.2(0, is recommended for use
by children weighing more than 20 pounds,
shall—

(a) Limit the resultant acceleration at the loca-
tion of the accelerometer mounted in the test
dummy head as specified in Part 572 such that
the expression:

(t2 - t.)

shall not exceed 1,000, where a is the resultant
acceleration expressed as a multiple of g (the
acceleration of gravity), and ti and t2, are any two
moments during the impacts.

(b) Limit the resultant acceleration at the loca-
tion of the accelerometer mounted in the test
dummy upper thorax as specified in Part 572 to
not more than 60 g's, except for intervals whose
cumulative duration is not more than 3 milli-
seconds.

S5.1.3 Occupant excursion. [When tested in
accordance with S6.1, each child restraint system
shall meet the applicable excursion limit require-
ments specified in S5. 1.3. 1-S5. 1.3.3. (57 F.R.
41423— September 10, 1992. Effective: March 9,
1993)]

S5.1.3.1 Child restraint systems other than
rear-facing ones and car beds. Each child
restraint system, other than a rear-facing child
restraint system or a car bed, shall retain the test
dummy's torso within the system.

(a) In the case of an add-on child restraint sys-
tem, no portion of the test dummy's head shall
pass through the vertical transverse plane that is
32 inches forward of point Z on the standard seat
assembly, measured along the center SORL (as
illustrated in Figure IB), and neither knee pivot
point shall pass through the vertical, transverse
plane that is 36 inches forward of point Z on the
standard seat assembly, measured along the center
SORL.

(b) In the case of a built-in child restraint sys-
tem, neither knee pivot shall pass through a verti-
cal, transverse plane that is 36 inches forward of
the hinge point of the specific passenger car seat
into which the system is built, measured along a
horizontal line parallel to the vehicle's longitu-
dinal center line and the center line of the pas-
senger car seat.

PART 571; S 213-2

_^Upper Torso Belt Anchorage Point

Anchorage Point on
Rear Package Shelf

-O

Rear Lap Belt
Buckle Location

Ref. NHTSA Drawing
No. SAS-1000

Notes: (1 ) Upper Torso Belt Anchorae Point Located Excursion Point

21 .4" Right or Lett of the Center SORL
as shown in Fig. 1A
(2) Rear Lap Belt Buckle Located 7.0" Right or
Left of the Center SORL as shown in Fig. 1 A

Figure 1B— Locations of Additional Belt Anchorage Points and Forward Excursion Limit

Seatback frontal surface plane extended

Foreward Limit

Note: The limits

illustrated move
during dynamic
testing

Figure 1C— Rear Facing Child Restraint Forward and Upper Head Excursion Limits

PART 571; S 213-3

55.1.3.2 Rear-facing child restraint systems. width of not less than 6 inches, measured in the
In the case of each rear-facing child restraint sys- horizontal plane of the height specified in para-
tem. all portions of the test dummy's torso shall graph (a) of this section.

be retained within the system and no portion of (c) Limits the rearward rotation of the test

the target point on either side of the dummy's dummy head so that the angle between the head

head shall pass through the transverse orthogonal and torso of the dummy specified in 57 when

planes whose intersection contains the forward- tested in accordance with S6.1 is not more than

most and top-most points on the child restraint 45 degrees greater than the angle between the

system surfaces (illustrated in Figure IC). head and torso after the dummy has been placed

in the system in accordance with S6. 1.2.3 and

55.1.3.3 Car beds. In the case of car beds, all before the system is tested in accordance with
portions of the test dummy's head and torso shall 35 j

be retained within the confines of the car bed.

S5.2.1.2 [A front facing child restraint system is

S5.1.4 Bacl< support angle. When a rear-facing not required to comply with S5.2.1.1 if the target

child restraint system is tested in accordance with point on either side of the dummy's head is below

S6.1, the angle between the system's back support a horizontal plane tangent to the top of—

surface for the child and the vertical shall not (a) The standard seat assembly, in the case of

exceed 70 degrees. an add-on child restraint system, when the

dummy is positioned in the system and the sys-

S5.2 Force distribution. tem is installed on the assembly in accordance

S5.2.1 Minimum head support surface-child ,. ^ t^. » .u e

restraints other than car beds. ^ ^^\ The passenger car seat, in the case of a

built-m child restraint system, when the system is
activated and the dummy is positioned in the sys-

S5.2.1.1 Except as provided in S5.2.1.2, each tem in accordance with S6.1.2. (53 F.R. 1783—

child restraint system other than a car bed shall January 22, 1988. Effective: January, 22, 1988)]
provide restraint against rearward movement of

the head of the child (rearward in relation to the S5.2.2 Torso impact protection. Each child

child) by means of a continuous seat back which restraint system other than a car bed shall comply

is an integral part of the system and which— with the applicable requirements of S5.2.2.1 and

(a) Has a height, measured along the system S5.2.2.2.
seat back surface for the child in the vertical

longitudinal plane passing through the longitu- S5.2.2.1 (a) The system surface provided for the

dinal centerline of the child restraint systems from support of the child's back shall be flat or concave

the lowest point on the system seating surface ^"d have a continuous surface area of not less

that is contacted by the buttocks of the seated than 85 square inches

dummy, as follows: ^h) Each system surface provided for support of

[ [ the side of the child's torso shall be flat or con-

Weight ' (in pounds) Heigiit- (in inches) ^ave and have a continuous surface of not less

Less than ''o lb 18 t^han 24 Square inches for systems recommended

20 lb or more, but not more than 40 lb 20 for children Weighing 20 pounds or more, or 45

°^^ ' ^ — square inches for systems recommended for chil-

us: S^chuVen'oVSr w^rghl^'^^""^'"^"'^' """" '''*' '"' dren weighing less than 20 pounds.

= The height of the portion of the system seat back providing head ((,) Each horizontal CrOSS SCCtion of Cach SyS-

restraint shall not be less than the above. .. , ■ , • r j

tem surface designed to restrain forward move-

(b) Has a width of not less than 8 inches meas- nient of the child's torso shall be flat or concave
ured in the horizontal plane at the height specified and each vertical longitudinal cross section shall
in paragraph (a) of this section. Except that a be flat or convex with a radius of curvature of the
child restraint system with side supports extend- underlying structure of not less than 2 inches.

ing at least 4 inches forward from the padded sur-
face of the portion of the restraint system pro- S5.2.2.2 [Each forward-facing child restraint sys-
vided for support of the child's head may have a tem shall have no fixed or movable surface —

(Rev. 1/22/88) PART 571; S 213-4

(a) Directly forward of the dummy and inter-
sected by a horizontal line —

( 1 ) Parallel to the 50RL, in the case of the
add-on child restraint system, or

(2) Parallel to a vertical plane through the
longitudinal center line of the passenger car
seat, in the case of the built-in child restraint
system, and (b) Passing through any portion of

the dummy, except for surfaces which restrain the
dummy when the system is tested in accordance
with S6. 1.2. 1.2, so that the child restraint system
shall conform to the requirements of S5.1.2 and
S5. 1.3.1. (53 F.R. 1783— January 22, 1988. Effec-
tive: January, 22, 1988)]

55.2.3 Head Impact protection.

55.2.3.1 Each child restraint system, other than a
child harness, which is recommended under
S5.5.2(f) for children weighing less than 20
pounds shall comply with S5.2.3.2.

55.2.3.2 Each system surface, except for protru-
sions that comply with S5.2.4, which is
contactable by the dummy head when the system
is tested in accordance with S6.1 shall be covered
with slow recovery, energy absorbing material
with the following characteristics:

(a) A 25 percent compression-deflection resist-
ance of not less than 0.5 and not more than 10
pounds per square inch when tested in accordance
with S6.3.

(b) A thickness of not less than Vi inch for
material having a 25 percent compression-deflec-
tion resistance of not less than 1.5 and not more
than 10 pounds per square inch when tested in
accordance with S6.3. Materials having a 25 per-
cent compression-deflection resistance of less than
1.8 pounds per square inch shall have a thickness
of not less than '^A inch.

55.2.4 Protrusion limitation. Any portion of a
rigid structural component within or underlying a
contactable surface, or any portion of a child
restraint system surface that is subject to the
requirements of S5.2.3 shall, with any padding or
other flexible overlay material removed, have a
height above any immediately adjacent restraint
system surface of not more than V» inch and no
exposed edge with a radius of less than 'A inch.

55.3 Installation.

55.3.1 Each [add-on] child restraint system shall
have no means designed for attaching the system
to vehicle seat cushion or vehicle seat back and no
component (except belts) that is designed to be
inserted between the vehicle seat cushion and
vehicle seat back. (53 F.R. 1783— January 22, 1988.
Effective: January, 22, 1988)

55.3.2 When installed on a vehicle seat, each
[add-on] child restraint system, other than child
harnesses, shall be capable of being restrained
against forward movement solely by means of a
Type I seat belt assembly (defined in S57 1.209)
that meets Standard No. 208 (S57 1.208), or by
means of a Type I seat belt assembly plus one
additional anchorage strap that is supplied with the
system and conforms to S5.4. (53 F.R. 1783—
January 22, 1988. Effective: January, 22, 1988)

55.3.3 Car beds. Each car bed shall be designed
to be installed on a vehicle seat so that the car
bed's longitudinal axis is perpendicular to a verti-
cal longitudinal plane through the longitudinal
axis of the vehicle.

55.4 Belts, belt buckles, and belt webbing.

S5.4.1 Performance requirements. The web-
bing of belts provided with a child restraint system
and used to attach the system to the vehicle or to
restrain the child within the system shall —

(a) After being subjected to abrasion as speci-
fied in § 5.1(d) or 5.3(c) of FMVSS No. 209
(§571.209), have a breaking strength of not less
than 75 percent of the strength of the unbraided
webbing when tested in accordance with S5.1(b)
of FMVSS No. 209.

(b) Meet the requirements of S4.3 (e) through
(h) of FMVSS No. 209 (S57 1.209); and

(c) If contactable by the test dummy torso
when the system is tested in accordance with
S6.1, have a width of not less than Wi inches
when measured in accordance with S5.4.1.1.

S5.4.1.1 Width test procedure. Condition the
webbing for 24 hours in an atmosphere of any rel-
ative humidity between 48 and 67 percent, and
any ambient temperature between 70° and 77° F.
Measure belt webbing width under a tension of 5
pounds applied lengthwise.

PART 571: S 213-5

(Rev. 1/22/88)

55.4.2 Belt buckles and belt adjustment hard-
ware. Each belt buckle and item of belt adjust-
ment hardware used in a child restraint system
shall conform to the requirements of S4.3 (a) and
S4.3 (b) of FMVSS No. 209 (S57 1.209).

55.4.3 Belt Restraint.

55.4.3.1 General. Each belt that is part of a
child restraint system and that is designed to
restrain a child using the system shall be adjust-
able to snugly fit any child whose height and
weight are within the ranges recommended in
accordance with S5.5.2 (f) and who is positioned
in the system in accordance with the instructions
required by S5.6.

55.4.3.2 Direct restraint. [Each belt that is part
of a child restraint system and that is designed to
restrain a child using the system and to attach the
system to the vehicle shall, when tested in accord-
ance with S6.1, impose no loads on the child that
result from the mass of the system, or

(a) in the case of an add-on child restraint sys-
tem, from the mass of the seat back of the stand-
ard seat assembly specified in S7.3, or (b) in the
case of a built-in child restraint system, from the
mass of any part of the vehicle into which the
child restraint system is built. (53 F.R. 1783 —
January 22, 1988. Effective: January, 22, 1988)]

55.4.3.3 Seating systems. Except for child
restraint systems subject to S5.4.3.4, each child
restraint system that is designed for use by a child
in a seated position and that has belts designed to
restrain the child shall, with the test dummy speci-
fied in S7 positioned in the system in accordance
with S6. 1.2.3, provide:

(a) upper torso restraint in the form of:

(i) belts passing over each shoulder of the
child; or

(ii) a fixed or movable surface that complies
with S5.2.2. 1(c), and

(b) lower torso restraint in the form of:

(i) a lap belt assembly making an angle
between 45° and 90° with the child restraint
seating surface at the lap belt attachment
points, or

(ii) a fixed or movable surface that complies
with S5.2.2.1(c), and

(i) a crotch belt connectable to the lap belt
or other device used to restrain the lower torso,
or ^—^

(ii) a fixed or movable surface that complies ^^
with S5.2.2.1(c).

55.4.3.4 Harnesses. Each child harness shall:

(a) Provide upper torso restraint, including belts
passing over each shoulder of the child;

(b) Provide lower torso restraint by means of
lap and crotch belt; and

(c) Prevent a child of any height for which the
restraint is recommended for use pursuant to
S5.5.2(f) from standing upright on the vehicle
seat when the child is placed in the device in
accordance with the instructions required by S5.6.

55.4.3.5 Buckle Release. Any buckle in a child
restraint system belt assembly designed to restrain
a child using the system shall;

(a) When tested in accordance with S6.2.1 prior
to the dynainic test of S6.1, not release when a
force of less than 9 pounds is applied and shall
release when a force of not more than 14 pounds
is applied:

(b) After the dynamic test of S6.1, when tested

in accordance with S6.2.3, release when a force ^^
of not more than 16 pounds is applied;

(c) Meet the requirements of S4.3(d)(2) of
FMVSS No. 209 (S57 1.209), except that the
minimum surface area for child restraint buckles
designed for push-button application shall be 0.6
square inch.

(d) Meet the requirements of S4.3(g) of
FMVSS No. 209 (S57 1.209) when tested in
accordance with S5.2(g) of FMVSS No. 209; and

(e) Not release during the testing specified in
S6.1.

S5.5 Labeling.

55.5.1 Each [add-on] child restraint system shall
be permanently labeled with the information
specified in S5.5.2 (a) through (I). (53 F.R. 1783—
January 22, 1988. Effective: January, 22, 1988)

55.5.2 The information specified in paragraphs
(a)-(m) of this section shall be stated in the Eng-
lish language and lettered in letters and numbers
that are not smaller than 10 point type and are on

a contrasting background. ^

(a) The model name or number of the system. ^

PART 571; S 213-6

(b) The manufacturer's name. A distributor's
name may be used instead if the distributor
assumes responsibihty for all duties and liabilities
imposed on the manufacturer with respect to the
system by the National Traffic and Motor Vehicle
Safety Act, as amended

inserting the month and year of manufacture.

(d) The place of manufacture (city and State, or
foreign country). However, if the manufacturer
uses the name of the distributor, then it shall state
the location (city and State, or foreign country) of
the principal offices of the distributor.

(e) The statement: "This child restraint system
conforms to all applicable Federal motor vehicle
safety standards."

(f) One of the following statements, inserting
the manufacturer's recommendations for the
maximum weight and height of children who can
safely occupy the system:

(i) This infant restraint is designed for use by

children who weigh pounds or less

and whose height is inches or less;

(ii) This child restraint is designed for use

only by children who weigh between

and pounds and whose height is

inches or less and who are capable

of sitting upright alone; or

(iii) This child restraint is designed for use

only by children who weigh between

and pounds and are between

_and

inches in height.

(g) The following statement, inserting the loca-
tion of the manufacturer's installation instruction
booklet or sheet on the restraint:
WARNING! FAILURE TO FOLLOW EACH OF
THE FOLLOWING INSTRUCTIONS CAN
RESULT IN YOUR CHILD STRIKING THE
VEHICLE'S INTERIOR DURING A SUDDEN
STOP OR CRASH.

SECURE THIS CHILD RESTRAINT WITH A
VEHICLE BELT AS SPECIFIED IN THE
MANUFACTURER'S INSTRUCTIONS

LOCATED

(h) In the case of each child restraint system
that has belts designed to restrain children using
them:

SNUGLY ADJUST THE BELTS PROVIDED
WITH THIS CHILD RESTRAINT AROUND
YOUR CHILD.

(i) [Reserved]

(j) In the case of each child restraint system
equipped with an anchorage strap, the statement:
SECURE THE TOP ANCHORAGE STRAP
PROVIDED WITH THIS CHILD RESTRAINT
AS SPECIFIED IN THE MANUFACTURER'S
INSTRUCTIONS.

(k) In the case of each child restraint system
which can be used in a rear-facing position, one
of the following statements:

(i) PLACE THIS CHILD RESTRAINT IN A

REAR-FACING POSITION WHEN USING IT

WITH AN INFANT; or

(ii) PLACE THIS INFANT RESTRAINT IN

A REAR-FACING POSITION WHEN USING

IT IN THE VEHICLE.

(1) An installation diagram showing the child
restraint system installed in the right front out-
board seating position equipped with a continu-
ous-loop lap/shoulder belt and in the center rear
seating position as specified in the manufacturer's
instructions, [(m) The following statement, insert-
ing an address and telephone number: "Child
restraints could be recalled for safety reasons.
You must register this restraint to be reached in
a recall. Send your name, address and the
restraint's model number and manufacturing date
to (insert address) or call (insert telephone num-
ber). For recall information, call the U.S. Govern-
ment's Auto Safety Hotline at 1-800-424-9393
(202-366-0123 in D.C. area)." (57 F.R. 41428—
September 10, 1992. Effective: March 9, 1993)]

(n) Child restraints that are certified as comply-
ing with the provisions of section S8 shall be
labeled with the statement "THIS RESTRAINT
IS CERTIFIED FOR USE IN MOTOR
VEHICLES AND AIRCRAFT". This statement
shall be in red lettering, and shall be placed after
the certification statement required by paragraph
(e) of this section.

55.5.3 The information specified in S5.5.2 (g)-(k)
shall be located on the add-on child restraint sys-
tem so that it is visible when the system is
installed as specified in S5.6.1.

55.5.4 [Each build-in child restraint system shall
be permanently labeled with the information
specified in S5.5.5(a) through (j), so that it is visi-
ble when the system is activated for use as speci-
fied in S5.6.2., and, except a factory-installed
built-in restraint, shall be permanently labeled
with the information specified in S5.5.5(k). (57

PART 571: S 213-7

(Rev. 9/10/92)

F.R. 41428— September 10, 1992. Effective: March
9. 1993)]

S5.5.5 [The information specified in paragraphs
(a) through (k) of this section shall be stated in the
English language and lettered in letters and num-
bers which are not smaller than 10-point type and
are on a contrasting background. This infonnation
specified in paragraphs (a) through (j) shall be
printed in the vehicle owner's manual. (57 F.R.
41428— September 10, 1992. EfTective: March 9,
1993)]

(a) The model name or number of the system.

(b) The manufacturer's name. A distributor's or
dealer's name may be used instead if the distribu-
tor or dealer assumes responsibility for all duties
and liabilities imposed on the manufacturer with
respect to the system by the National Traffic and
Motor Vehicle Safety Act, as amended.

inserting the month and year of manufacture.

(d) The place of manufacture (city and State, or
foreign country). However, if the manufacturer
uses the name of the distributor or dealer, then it
shall state the location (city and State, or foreign
country) of the principal offices of the distributor
or dealer.

(e) The statement: "This child restraint system
confoims to all applicable Federal motor vehicle
safety standards.

(f) One of the following statements, inserting
the manufacturer's recommendations for the
maximum weight and height of children who can
safely occupy the system:

(i) This infant restraint is designed for use by

children who weigh pounds or less and

whose height is inches or less;

(ii) This child restraint is designed for use

only by children who weigh between and

pounds and whose height is inches

or less and who are capable of sitting upright
alone; or

(iii) This child restraint is designed for use

by children who weigh between and

pounds and are between and inches

in height.

(g) [The statement specified in paragraph (1),
and if appropriate, the statement in paragraph (2):

(i) WARNING! FAILURE TO FOLLOW
THE MANUFACTURER'S INSTRUCTIONS
ON THE USE OF THIS CHILD RESTRAINT
SYSTEM CAN RESULT IN YOUR CHILD

STRIKING THE VEHICLE'S INTERIOR
DURING A SUDDEN STOP OR CRASH.

(ii) In the case of each built-in child restraint sys-
tem which is not intended for use in the motor
vehicle at certain adjustment positions, the follow-
ing statement, inserting the manufacturer's adjust-
ment restrictions. DO NOT USE THE

ADJUSTMENT POSITION(S) OF THIS CHILD
RESTRAINT WHILE THE VEHICLE IS IN
MOTION. (57 F.R. 41423— September 10, 1992.
Effective: March 9, 1993)]

(h) In the case of each build-in child restraint
system that has belts designed to restrain children
using them:

SNUGLY ADJUST THE BELTS PROVIDED
WITH THIS CHILD RESTRAINT AROUND
YOUR CHILD.

(i) In the case of each built-in child restraint
which can be used in a rear, facing position, the
following statement:

PLACE AN INFANT IN A REAR-FACING
POSITION IN THIS CHILD RESTRAINT.

(j) A diagram or diagrams showing the fully
activated child restraint system in infant and/or
child configurations, [(k) The following state-
ment, inserting an address and telephone number:
"Child restraints could be recalled for safety rea-
sons. You must register this restraint to be
reached in a recall. Send your name, address and
the restraint's model number and manufacturing
date to (insert address) or call {insert telephone
number). For recall information, call the U.S.
Government's Auto Safety Hotline at 1-800-424-
9393 (202-366-0123 in D.C. area)." (57 F.R.
41428— September 10, 1992. Effective: March 9,
1993)]

S5.6 Printed Instructions for Proper Use.

S5.6.1 Add-on restraint systems. Each add-on
child restraint system shall be accompanied by
printed installation instructions in the English lan-
guage that provide a step-by-step procedure,
including diagrams, for installing the system in
motor vehicles, securing the system in the
vehicles, positioning a child in the system, and
adjusting the system to fit the child.

S5.6.1.1 In a vehicle with rear designated seating
positions, the instructions shall alert vehicle own-
ers that, according to accident statistics, children
are safer when properly restrained in the rear seat-
ing positions than in the front seating positions.

(Rev. 9/10/92)

PART 571; S 213-8

55.6.1.2 The instructions shall specify in general
terms the types of vehicles, the types of seating
positions, and the types of vehicle safety belts
with which the add-on child restraint system can
or cannot be used.

55.6.1 .3 The instructions shall explain the primary
consequences of not following the warnings
required to be labeled on the child restraint system
in accordance with S5.5.2(g) through (k).

55.6.1.4 The instructions for each car bed shall
explain that the car bed should position in such a
way that the child's head is near the center of the
vehicle.

55.6.1.5 The instructions shall state that add-on
child restraint systems should be securely belted to
the vehicle, even when they are not occupied,
since in a crash an unsecured child restraint sys-
tem may injure other occupants.

55.6.1.6 Each add-on child restraint system shall
have a location on the restraint for storing the
manufacturer's instructions.

[S5.6.1.7 The instructions shall include the fol-
lowing statement, inserting an address and tele-
phone number: "Child restraints could be recalled
for safety reasons. You must register this restraint
to be reached in a recall. Send your name, address
and the restraint's model number and manufactur-
ing date to (insert address) or call (insert tele-
phone number). For recall information, call the
U.S. Government's Auto Safety Hotline at 1-800-
424-9393 (202-366-0123 in D.C. area)." (57 F.R.
41428— September 10, 1992. Effective: March 9,
1993)]
(Rev. 9/10/92)

S5.6.2 Built-in child restraint systems. Each
built-in child restraint system shall be accom-
panied by printed instructions in the English lan-
guage that provide a step-by-step procedure,
including diagrams, for activating the built-in
child restraint system, positioning a child in the
system, adjusting the restraint and, if provided, the
restraint harness to fit the child. This information
and the information specified in S5.5.5, shall be
included in the vehicle owner's manual.

S5.6.2.1 The instructions shall explain the primary
consequences of not following the manufacturer's

warnings for proper use of the child restraint sys-
tem in accordance with S5.5.5(f) through (i).

[S5.6.2.2 The instructions for each built-in child
restraint system, except a factory-installed
restraint, shall include the following statement,
inserting an address and telephone number:
"Child restraints could be recalled for safety rea-
sons. You must register this restraint to be reached
in a recall. Send your name, address and the
restraint's model number and manufacturing date
to (insert address) or call (insert telephone num-
ber). For recall information, call the U.S. Govern-
ment's Auto Safety Hotline at 1-800-424-9393
(202-366-0123 in D.C. area)." (57 F.R. 41428—
September 10, 1992. Effective: March 9, 1993)]

55.6.3 The instructions shall explain the primary
consequences of noting following the warnings
required to be labeled on the child restraint system
in accordance with S5.5.2 (g)-(k).

55.6.4 The instructions for each car bed shall
explain that the car bed should position in such a
way that the child's head is near the center of the
vehicle.

55.6.5 The instructions shall state that child
restraint systems should be securely belted to the
vehicle, even when they are not occupied, since in
a crash an unsecured child restraint system may
injure other occupants.

55.6.6 Each child restraint system shall have a
location on the restraint for storing the manufac-
turer's instructions.

S5.7 Flammability. Each material used in a child
restraint system shall conform to the requirements
of S4 of FMVSS No. 302 (S57 1.302). In the case
of a built-in child restraint system, the require-
ments of 54 of FMVSS No. 302 shall be met in
both "in-use" and "stowed" positions.

[S5.8 Information requirements— registration
form.

(a) Each child restraint system, except a fac-
tory-installed build-in restraint system, shall have
a registration form attached to any surface of the
restraint that contacts the dummy when the
dummy is positioned in the system in accordance
with S6.1.2 of Standard 213.

(b) Each fonn shall:

PART 571; S 213-9

(Rev. 9/10/92)

(1) Consist of a postcard that is attached at
a perforation to an informational card:

(2) Conform in size, content and format to
Figures 9a and 9b; and

(3) Have a thicicness of at least 0.007 inches
and not more than 0.0095 inches, (c) Each post-
card shall provide the model name or number and
date of manufacture (month, year) of the child
restraint system to which the form is attached,
shall contain space for the purchaser to record his
or her name and mailing address, shall be
addressed to the manufacturer, and shall be post-
age paid. No other information shall appear on
the postcard, except identifying information that
distinguishes a particular child restraint system
from other systems of that model name or number
may be preprinted in the shaded area of the post-
card, as shown in figure 9a. (57 F.R. 41428 —
September 10, 1992. Effective: March 9, 1993)]

S6. Test Conditions and Procedures.

S6.1 Dynamic Systems Test.

S6.1.1 Test Conditions.

S6.1.1.1 [(a) The test device for add-on child
restraint systems is the standard seat assembly
specified in S7.3. The assembly is mounted on a
dynamic test platform so that the center SORL of
the seat is parallel to the direction of the test plat-
form travel and so that movement between the
base of the assembly and the platfomi is pre-
vented.

(b) The test device for built-in child restraint
systems is either the specific vehicle shell or the
specific vehicle.

(l)(i) The specific vehicle shell, if selected
for testing, is mounted on a dynamic test plat-
form so that the longitudinal center line of the
shell is parallel to the direction of the test plat-
form travel and so that movement between the
base of the shell and the platfomi is prevented.
Adjustable seats are in the adjustment position
midway between the forwardmost and rearmost
position, and if separately adjustable in a verti-
cal direction, are at the lowest position. If an
adjustment position does not exist midway
between the forwardmost and reaiTnost position,
the closest adjustment position to the rear of
the midpoint is used. Adjustable seat backs are
in the manufacturer's nominal design riding

position. If such a position is not specified, the
seat back is positioned so that the longitudinal
center line of the child test dummy's neck is
vertical, and if an instrumented test dummy is
used, the accelerometer surfaces in the dum-
my's head and thorax, as positioned in the
vehicle, are horizontal. If the vehicle seat is
equipped with adjustable head restraints, each
is adjusted to its highest adjustment position.

(ii) The platform is instrumented with an
accelerometer and data processing system hav-
ing a frequency response of 60Hz channel class
as specified in Society of Automotive Engi-
neers Recommended Practice J211 JUN80
■'Instrumentation for Impact Tests." The accel-
erometer sensitive axis is parallel to the direc-
tion of the test platform travel. (2) For built-
in child restraint systems, an alternative test
device is the specific vehicle into which the built-
in system is fabricated. The following test condi-
tions apply to this alternate test device. (57 F.R.
41428— September 10, 1992. Effective: March 9,
1993)]

(c) For built-in child restraint systems, an alter-
nate test device is the specific vehicle into which
the build-in system is fabricated. Activate the sys-
tem in accordance with the manufacturer's
instructions provided in the vehicle owner's man-
ual in accordance with S5.6.2. When the complete
vehicle traveling longitudinally forward at any
speed up to and including 30 mph, impacts a
fixed collision barrier that is perpendicular to the
line of travel of the vehicle, the built-in child
restraint system shall meet the injury criteria of
S5.1.2. The following test conditions apply to this
alternate test device.

(i) The vehicle is loaded to its unloaded
vehicle weight plus its rated cargo and luggage
capacity weight, secured in the luggage area,
plus the appropriate child test dummy and, at
the option of the manufacturer, an
anthropomorphic test dummy which conforms
to the requirements of Subpart B or Subpart E
of Part 572 of this title for a 50th percentile
adult male dummy placed in the front outboard
seating position. If the built-in child restraint
system is installed at one of the seating posi-
tions otherwise requiring the placement of a
Part 572 test dummy, then in the frontal bairier
crash specified in S6. 1.1.2, the appropriate
child test dummy shall be substituted for the
Part 572 test dummy, but only at that seating

(Rev. 9/10/92)

PART 571; S 213-10

position. The fuel tank is filled to any level
from 90 to 95 percent of capacity.

(ii) Adjustable seats are in the adjustment
midway between the forward-most and rear-
most positions, and if separately adjustable in a
vertical direction, are at the lowest position. If
an adjustment position does not exist midway
between the forward-most and rear-most posi-
tions, the closest adjustment position to the rear
of the midpoint is used.

(iii) Adjustable seat backs are iii the manu-
facturer's nominal design riding position. If a
nominal position is not specified, the seat back
is positioned so that the longitudinal center line
of the child test dummy's neck is vertical, and
if an anthropomorphic test dummy is used, the
accelerometer surfaces in the test dummy's
head and thorax, as positioned in the vehicle,
are horizontal. If the vehicle is equipped with
adjustable head restraints, each is adjusted to its
highest adjustment position.

(iv) Movable vehicle windows and vents are,
at the manufacturer's option, placed in the fully
closed position.

(v) Convertibles and open-body type vehicles
have the top, if any, in place in the closed pas-
senger compartment configuration.

(vi) Doors are fully closed and latched but
not locked.

(vii) All instrumentation and data reduction
is in conformance with SAE J211 JUN80.

S6.1.1.2 [The tests are frontal barrier impact sim-
ulations of the test platform or frontal barrier
crashes of the specific vehicles as specified in
S5.1 (571.208) and for;

(a) Test Configuration I specified in S6. 1.2. 1.1,
are at a velocity change of 30 mph with the accel-
eration of the test platform entirely within the
curve shown in Figure 2, or for the specific
vehicle test with the deceleration produced in 30
mph frontal barrier crash, (b) Test Configuration
II specified in S6. 1.2. 1.2 are set at a velocity
change of 20 mph with the acceleration of the test
platform entirely within the curve shown in Fig-
ure 3, or for the specific vehicle test with the
deceleration produced in 20 mph frontal barrier
crash. (53 F.R. 1783— January 22, 1988. Effective:
January, 22, 1988)]

ACCELERATION FUNCTION FOR AV = 30 MPH

TIME— MILLISECONDS

Figure 2

ACCELERATION FUNCTION FOR AV = 30 MPH

TIME— MILLISECONDS

Figure 3

56.1.1.3 In the case of add-on child restraint sys-
tems. Type I seat belt assemblies meeting the
requirements of Standard No. 209 (S57 1.209) and
having webbing with a width of not more than 2
inches are attached, without the use of retractors
or reels of any kind, to the seat belt anchorage
points (illustrated in Figure IB) provided on the
standard seat assembly.

56.1.1.4 Performance tests under S6.1 are con-
ducted at any ambient temperature from 66° to
78° F and at any relative humidity from 10 per-
cent to 70 percent.

[S6.1.1.5 In the case of add-on child restraint sys-
tems, the restraint shall meet the requirements of
S5 at each of its seat back angle adjustment posi-
tions and restraint belt routing positions, when the
restraint is oriented in the direction recommended
by the manufacturer (e.g., forward, rearward or
laterally) pursuant to S5.6, and tested with the test

PART 571: S 213-1:

(Rev. 1/22/88)

dummy specified in S7. (57 F.R. 41423— Septem-
ber 10, 1992. Effective: March 9, 1993)]

S6.1.2 Dynamic Test Procedure.

56.1.2.1 Test Configuration.

56.1.2.1.1 Test Configuration (a) In the case of
eacii add-on child restraint system other than a
child harness, a booster seat with a top anchorage
strap, or a restraint designed for use by physically
handicapped children, install a new add-on child
restraint system at the center seating position of
the standard seat assembly in accordance with the
manufacturer's instructions provided with the sys-
tem pursuant to S5.6.1, except that the add-on
restraint shall be secured to the standard vehicle
seat using only the standard vehicle lap belt. A
child harness, booster seat with a top anchorage
strap, or a restraint designed for use by physically
handicapped children shall be installed at the cen-
ter seating position of the standard seat assembly
in accordance with the manufacturer's instructions
provided with the system pursuant to S5.6.1.

(b) In the case of each built-in child restraint
system, activate the restraint in the specific
vehicle shell or the specific vehicle, in accordance
with the manufacturer's instructions provided in
the vehicle owner's manual in accordance with
S5.6.2.

56.1.2.1.2 Test Configuration II. (a) In the case
of each add-on child restraint system which is
equipped with a fixed or movable surface
described in S5.2.2.2, or a booster seat with a top
anchorage strap, install a new add-on child
restraint system at the center seat position of the
standard seat assembly using only the standard
seat lap belt to secure the system to the standard
seat.

(b) In the case of each built-in child restraint
system which is equipped with a fixed or mov-
able surface described in S5.2.2.2, or a built-in
booster seat with a top anchorage strap, activate
the system in the specific vehicle shell or the spe-
cific vehicle in accordance with the manufactur-
er's instructions provided in the vehicle owner's
manual in accordance with S5.6.2.

56.1.2.2 Tighten all belts used to attach the add-
on child restraint system to the standard seat
assembly to a tension of not less than 12 pounds
and not more than 15 pounds, as measured by a

load cell used on the webbing portion of the belt.
Tighten all manual vehicle belts used to secure the
built-in child restraint system or a child to the spe- ^^
cific vehicle shell or specific vehicle to one of the ^*
following tensions:

(a) For a seat equipped with a manual adjuster
or automatic locking retractor, not less than 12
pounds and not more than 15 pounds, as meas-
ured by a load cell used on the webbing portion
of the belt;

(b) For a seat equipped with an emergency
locking retractor, as specified in S4.3 of Standard
209.

S6.1.2.3 Place in the child restraint any dummy
specified in 57 for testing systems for use by chil-
dren of the heights and weights for which the sys-
tem is recommended in accordance with S5.6.

S6.1. 2.3.1 When placing the 3-year-old test
dummy in add-on or built-in child restraint sys-
tems other than car beds, position the test dummy
according to the instructions for child positioning
provided by the manufacturer with the system in
accordance with S5.6.1 or S5.6.2 while conform-
ing to the following:

(a) Holding the test dummy torso upright until ^
it contacts the system's design seating surface,

place the test dummy in the seated position within
the system with the midsagittal plane of the test
dummy head —

(i) coincident with the center SORL of the

standard seating assembly, in the case of the

add-on child restraint system, or

(ii) vertical and parallel to the longitudinal

center line of the specific vehicle shell or the

specific vehicle, in the case of a built-in child

restraint system.

(b) Extend the arms of the test dummy as far
as possible in the upward vertical direction.
Extend the legs of the dummy as far as possible
in the forward horizontal direction, with the
dummy feet perpendicular to the centerline of the
lower legs.

(i) the plane of the back of the standard seat
assembly in the case of an add-on child
restraint system, or ^

(ii) the back of the vehicle seat in the spe- "
cific vehicle shell or the specific vehicle in the

(Rev. 9/10/92)

PART 571; S 213-12

case of a build-in child restraint system, first
against the dummy crotch and then at the
■K\ dummy thorax in the midsagittal plane of the

W dummy. For a child restraint system with a

fixed or movable surface described in S5.2.2.2
which is being tested under the conditions of
test configuration II, do not attach any of the
child restraint belts unless they are an integral
part of the fixed or movable surface. For all
other child restraint systems and for a child
restraint system with a fixed or movable sur-
face which is being tested under the conditions
of test configuration I, attach all appropriate
child restraint belts and tighten them as speci-
fied in S6. 1.2.4. Attach all appropriate vehicle
belts and tighten them as specified in S6.1.2.2.
Position each movable surface in accordance
with the manufacturer's Instructions provided
in accordance with S5.6.1 or S5.6.2.
(d) After the steps specified in paragraph (c) of
this section, rotate each dummy limb downwards
in the plane parallel to the dummy's midsagittal
plane until the limb contacts a surface of the child
restraint system or the standard seat assembly in
the case of an add-on system, or the specific
1^ vehicle shell or specific vehicle in the case of a
W built-in system, as appropriate. Position the limbs,
if necessary, so that limb placement does not
inhibit torso or head movement in tests conducted
under S6.

S6. 1.2.3.2 When placing the 6-month-old dummy
in [add-on or built-in] child restraint systems
other than car beds, position the test dummy
according to the instructions for child positioning
provided with the system by the manufacturer in
accordance with [S5.6.1 or S5.6.2] while
conforming to the following:

(a) With the dummy in the supine position on
a horizontal surface, and while preventing move-
ment of the dummy torso by placing a hand on
the center of the torso, rotate the dummy legs
upward by lifting the feet until the legs contact
the upper torso and the feet touch the head, and
then slowly release the legs but do not return
them to the tlat surface.

(b) Place the dummy in the child restraint sys-
tem so that the back of the dummy torso contacts
the back support surface of the system. For a

\ child restraint system with a fixed or movable

^ surface described in S5.2.2.2 which is being

tested under the conditions of test configuration

II, do not attach any of the child restraint belts
unless they are an integral part of the fixed or
movable surface. For all other child restraint sys-
tems and for a child restraint system with a fixed
or movable surface which is being tested under
the conditions of test configuration I, attach all
appropriate child restraint belts and tighten them
as specified in S6. 1.2.4. Attach all appropriate
vehicle belts and tighten them as specified in
S6. 1.2.2. Position each movable surface in
accordance with the manufacturer's instructions
provided in accordance with [S5.6. 1 or S5.6.2.]
If the dummy's head does not remain in the
proper position, it shall be taped against the front
of the seat back surface of the system by means
of a single thickness of '/i-inch-wide paper mask-
ing tape placed across the center of the dummy
face, (c) Position the dummy arms vertically
upwards and then rotate each arm downward
toward the dummy's lower body until it contacts
a surface of the child restraint system or the
standard seat assembly, [in the case of an add-on
child restraint system, or the specific vehicle shell
or the specific vehicle in the case of a built-in
child restraint system, ensuring that no ann is
restrained from movement in other than the
downward direction, by any part of the system or
the belts used to anchor the system to the stand-
ard seat assembly, the specific vehicle shell, or
the specific vehicle.] (53 F.R. 1783 — January 22,
1988. Effective: January 22, 1988)

S6. 1.2.3.3 When placing the 6-month-old dummy
or 3-year-old dummy in a car bed, place the
dummy in the car bed in the supine position with
its midsagittal plane perpendicular to the center
SORL of the standard seat assembly and position
the dummy within the car bed in accordance with
instructions for child positioning provided with the
car bed by its manufacturer in accordance with
S5.6.

S6.1 .2.4 If provided, shoulder and pelvic belts that
directly restrain the dummy shall be adjusted as
follows:

Tighten the belts until a 2-pound force applied
(as illustrated in Figure 5) to the webbing at the
top of each dummy shoulder and to the pelvic
webbing two inches on either side of the torso
midsagittal plane pulls the webbing '/4 inch from
the dummy.

PART 571; S 213-13

(Rev. 1/22/88)

56.1.2.5 Accelerate the test platform to simulate
frontal impact in accordance with S6. 1.1.2 (a) or
S6. 1.1.2. (b), as appropriate.

56.1.2.6 [For add-on child restraint systems,
measure dummy excursion and detemiine
conformance with the requirements specified in

55.1 as appropriate. For built-in child restraint
systems, measure dummy knee excursion and
determine conformance with the requirements
specified in S5.1 as appropriate. (53 F.R. 1783 —
January 22. 1988. Effective: January. 22, 1988)]

56.2 Buckle release test procedure. The belt
assembly buckles used in the child restraint sys-
tem shall be tested in accordance with S6.2.1
through S6.2.4 inclusive.

S6.2.1 Before conducting the testing specified in
S6.1, place the loaded buckle on a hard, flat, hori-
zontal surface. Each belt end of the buckle shall
be pre-loaded in the following manner. The anchor
end of the buckle shall be loaded with a 2-pound
force in the direction away from the buckle. In the
case of buckles designed to secure a single latch
plate, the belt latch plate end of the buckle shall
be pre-loaded with a 2-pound force in the direc-
tion away from the buckle. In the case of buckles
designed to secure two or more latch plates, the
belt latch plate ends of the buckle shall be loaded
equally so that the total load is 2 pounds in the
direction away from the buckle. For push-button
release buckles the release force shall be applied
by a conical surface (cone angle not exceeding 90
degrees). For push-button release mechanisms
with a fixed edge (referred to in Figure 7 as
"hinged button"), the release force shall be
applied at the centerline of the button, 0.125
inches away from the movable edge directly oppo-
site the fixed edge, and in the direction that pro-
duces maximum releasing effect. For push-button
release mechanisms with no fixed edge (referred
to Figure 7 as "floating button"), the release
force shall be applied at the center of the release
mechanism in the direction that produces the

maximum releasing effect. For all other buckle
release mechanisms, the force shall be applied on
the centerline of the buckle lever or finger tab in
the direction that produces the maximum releasing
effect. Measure the force required to release the
buckle. Figure 7 illustrates the loading for the dif-
ferent buckles and the point where the release
force should be applied, and Figure 5 illustrates
the conical surface used to apply the release force
to push-button release buckles.

S6.2.2 After completion of the testing specified in
S6. 1 , and before the buckle is unlatched, tie a self-
adjusting sling to each wrist and ankle of the test
dummy in the manner illustrated in Figure 4.

Pull Horizontally

Figure 4 — Buckle Release Test

56.2.3 [Pull the sling horizontally in the manner
illustrated in Figure 4 and parallel to the center
SORL of the seat assembly, in the case of an add-
on child restraint system, or parallel to the longitu-
dinal center line of either the specific vehicle shell
or the specific vehicle, in the case of a built-in
child restraint system, and apply a force of 20
pounds in the case of a system tested with a 6
month-old dummy and 45 pounds in the case of
a system tested with a 3 year-old dummy. (53 F.R.
1783— January 22. 1988. Effective: January, 22,
1988)]

56.2.4 While applying the force specified in
S6.2.3, and using the device shown in Figure 8 for
push-button release buckles, apply the release
force in the manner and location specified in
S6.2.1 for that type of buckle. Measure the force
required to release the buckle.

(Rev. 1/22/88)

PART 571; S 213-14

S6.3 Head impact protection— energy absorb-
ing material test procedure.

S6.3.1 Prepare and test specimens of the energy
absorbing material used to comply with S5.2.3 in
accordance with the applicable 25 percent
compression-deflection test described in the Amer-
ican Society for Testing and Materials (ASTM)
Standard D 1056-73, "Standard Specification for
Flexible Cellular Materials — Sponge or Expanded
Rubber", or D 1564-71. "Standard Method of
Testing Flexible Cellular Materials — Slab Ure-
thane Foam" or D1565-76 "Standard Specifica-
tion for Flexible Cellular Materials — Vinyl Chlo-
ride Polymer and Copolymer open-cell foams.

S7 Test dummies.

57.1 Six-month-old dummy. An unclothed
"Six-month-old Size Manikin" conforming to
Subpart D of Part 572 of this chapter is used for
testing a child restraint system that is rec-
ommended by its manufacturer in accordance with
S5.6 for use by children in a weight range that
includes children weighing not more than 20
pounds.

57.2 Three-year-old dummy. A three-year-old
dummy confomiing to Subpart C of Part 572 of
this chapter is used for testing a child restraint that
is recommended by its manufacturer in accordance
with S5.6 for use by children in a weight range
that includes children weighing more than 20
pounds.

[(a) Built-in child restraints. When a three-
year-old test dummy is used for testing a built-in
child restraint, the dummy shall be assembled
with the head assembly specified in
§572. 16(a)(1).

(b) Add-on child restraints. Until September 1,
1993, when a three-year-old test dummy is used
for testing an add-on child restraint, the dummy
shall be assembled using, at the manufacturer's
option, either head assembly specified in
§ 572.16(a). Effective September 1, 1993, when a
three-year-old dummy is used for testing an add-
on child restraint, the dummy shall be assembled
with the head assembly specified in
§ 572.16(a)(1). (55 F.R. 30465— July 26, 1990.
EfTective: August 27, 1990.]

Insert Webbing'

to Rest Against

This Surface

1/16 inch diameter wire

•H Dimension B

Direction of Pull

Dimension A - Width of Webbing Plus 1/8 inch
Dimension B - 1/2 of Dimension A

Figure 5 — Webbing Tension Pull Device

S7.2.1 Before being used in testing under this
standard, the dummy is conditioned at any
ambient temperature from 66° F to 78° F and at
any relative humidity from 10 percent to 70 per-
cent for at least 4 hours.

S7.2.2 When used in testing under this standard,
the dummy is clothed in thermal knit waffle-
weave polyester and cotton underwear, a size 4
long-sleeved shirt weighing 0.2 pounds, a size 4
pair of long pants weighing 0.2 pounds and cut off
just far enough above the knee to allow the knee
target to be visible, and size 7M sneakers with
rubber toe caps, uppers of dacron and cotton or
nylon and a total weight of 1 pound. Clothing
other than the shoes is machine-washed in 160° F
to 180° F water and machine dried at 120° F to
140° F for 30 minutes.

S7.3 Standard test devices.

(a) The standard test devices used in testing
add-on child restraint systems under this standard
are:

PART 571; S 213-13

(Rev. 7/26/90)

(1) For testing for motor vehicle use, a
standard seat assembly consisting of a simu-
lated vehicle bench seat, with three seating
positions, which is described in Drawing Pack-
age SAS-100-1000 (consisting of drawings and
a bill of materials); and

(2) For testing for aircraft use, a standard
seat assembly consisting of a representative air-
craft passenger seat.

(b) The standard test devices used in testing
built-in child restraint systems under this standard
are either a specific vehicle shell or a specific
vehicle.

S8. Requirements, test conditions, and proce-
dures for child restraint systems manufactured
for use in an aircraft. Each child restraint system
manufactured for use in both motor vehicles and
aircraft must comply with all of the applicable
requirements specified in section S5 and with the
additional requirement specified in S8.1 and S8.2.

S8.1 Installation instructions. [Each child
restraint system manufactured for use in aircraft
shall be accompanied by printed instructions in
English that provide a step-by-step procedure,
including diagrams, for installing the system in
aircraft passenger seats, securing a child in the
system when it is installed in aircraft, and adjust-
ing the system to fit the child. (57 F.R. 41423—
September 10, 1992. Effective: March 9, 1993)]

[S8.2 Inversion test. When tested in accordance
with S8.2.1 through S8.2.5, each child restraint
system manufactured for use in aircraft shall meet
the requirements of S8.2.1 through S8.2.6. The
manufacturer may, at its options, use any seat
which is a representative aircraft passenger seat
within the meaning of S4. Each system shall meet
the requirements at each of the restraint's seat
back angle adjustment positions and restraint belt
routing positions, when the restraint is oriented in
the direction recommended by the manufacturer
(e.g., facing forward, rearward or laterally) pursu-
ant to S8.1, and tested with the test dummy speci-
fied in S7. If the manufacturer recommendations
do not include instructions for orienting the
restraint in aircraft when the restraint seat back
angle is adjusted to any position, position the

restraint on the aircraft seat by following the
instructions (provided in accordance with S5.6)
for orienting the restraint in motor vehicles. (57 i^
F.R. 41423— September 10, 1992. Effective: March ^
9, 1993)]

S8.2.1 A representative aircraft passenger seat
shall be positioned and adjusted so that its hori-
zontal and vertical orientation and its seat back
angle are the same as shown in Figure 6.

Figure 6— Simulated Aircraft Passenger Seat

"A" represents a 2- to 3-inch thick poly-
urethane foam pad, 1.5-2.0 pounds per cubic foot
density, over 0.020-inch-thick aluminum pan, and
covered by 12- to 14-ounce marine canvas. The
sheet aluminum pan is 20 inches wide and sup-
ported on each side by a rigid structure. The seat
hack is a rectangular frame covered with the alu-
minum sheet and weighing betv^'een 14 and 15
pounds, with a center of mass 13 to 16 inches
above the seat pivot axis. The mass moment of
inertia of the seat back about the seat pivot axis
is between 195 and 220 ounce-inch-second ~. The
seat back is free to fold forward about the pivot,
but a stop prevents reaiward motion. The pas-
senger safety belt anchor points are spaced 21 to
22 inches apart and are located in line with the
seat pivot axis.

(Rev. 9/10/92)

PART 571; S 213-16

I I I 2 Pounds

7a. Single Latch Plate
Pre-load

Release Force

Applicati

Posilion

Buckle Pre-load

Release Force
Application Position-
Push Button
Mechanisms

^ W

— t—

7c. Hinged Button

Figure 7— Pre-impact Buckle Release Force Test Set-up

7d. Floating Button

_____i_

Qi3

Figure 8— Release Force Application Device— Push Button Release Buckles

PART 571; S 213-17

FOR YOUR CHILD'S CONTINUED SAFETY

Please take a few moments to promptly fill out and return the
attached card.

Although child restraint systems undergo testing and evaluation,
it is possible that a child restraint could be recalled.

In case of recall, we can reach you only if we have your name
and address, so please send in the card to be on our recall list

Please fill this card out and mail it NOW,
while you are thinking about it.

It's already addressed and we've paid the postage.

Tear off and mail this part

Consumer: Just tlll in your name and address.

Your name

Your street address

CHILD RESTRAINT REGISTRATION CARD

RESTRAINT MODEL XXX
SERIAL NUMBER YYYY
MANUFACTURED ZZ-ZZ-19ZZ

Preprinted

message to
^consumer; bold
'typeface, caps

and lower case

minimum 12 point

type.

FOLD / PERFORATION

Minimum 10%
screen tint.

Preprinted or
stamped child
safety seat
model name or
number and date
of manufacture.

Figure 9— Registration Form for Child Systems— Product Identification Number and Purchaser

Information Side.

[(57 F.R. 41428— September 10, 1992.
Effective: March 9, 1993)]

(Rev. 9/10/92)

PART 571; S 213-18

)

3.5"
minimum

IMPORTANT

In case of a recall, we can reach you only if we
have your name and address. You MUST send in
the attached card to be on our recall list

We've already paid the postage.
Do it today.

NO POSTAGE

NECESSARY

IF MAILED

IN THE

UNITED STATES

MANUFACTURER
POST OFFICE BOX 0000
ANYTOWN, ST 12345-6789

Block letters
(sans serif)— Bold
minimum 48 point
type. caps.

Minimum 10%
screen tint

Preprinted
message to
consumer; bold
typeface, caps
and lower case
minimum 12 point
type.

FOLD / PERFORA TION

Preprinted or
stamped name
and address of
manufacturer or
its designee.

Figure 10— Registration Form for Child Restraint Systems— Address Side.
[(57 F.R. 41428— September 10, 1992. Effective: March 9, 1993)]

PART 571: S 213-19

(Rev. 9/10/92)

58.2.2 The child restraint system shall be attached
to the representative aircraft passenger seat using,
at the manufacturer's options, any Federal Avia-
tion Administration approved aircraft safety belt,
according to the restraint manufacturer's instruc-
tions for attaching the restraint to an aircraft seat.
No supplementary anchorage belts or tether straps
may be attached; however. Federal Aviation
Administration approved safety belt extensions
may be used.

58.2.3 In accordance with S6. 1.2.3.1 through
S6. 1.2.3.3, place in the child restraint any dummy
specified in S7 for testing systems for use by chil-
dren of the heights and weights for which the sys-
tem is recommended in accordance with S5.5 and
S8.1.

58.2.4 If provided, shoulder and pelvic belts that
directly restrain the dummy shall be adjusted in
accordance with S6. 1.2.4.

58.2.5 The combination of representative aircraft
passenger seat, child restraint and test dummy
shall be rotated forward around a horizontal axis
which is contained in the median transverse verti-
cal plane of the seating surface portion of the air-
craft seat and is located one inch below the bot-
tom of the seat frame, at a speed of 35 to 45
degrees per second, to an angle of 180 degrees.
The rotation shall be stopped when it reaches that
angle and the seat shall be held in this position for
three seconds. The child restraint shall not fall out

of the aircraft safety belt, nor shall the test dummy
fall out of the child restraint at any time during the
rotation or the three second period. The specified
rate of rotation shall be attained in not less than
one-half second, and not more than one second,
and the rotating combination shall be brought to
a stop in not less than one half second and not
more than one second.

S8.2.6 Repeat the procedures set forth in S8.2.1
through S8.2.4. The combination of the represent-
ative aircraft passenger seat, child restraint, and
test dummy shall be rotated sideways around a
horizontal axis which is contained in the median
longitudinal vertical plane of the seating surface
portion of the aircraft seat and is located one inch
below the bottom of the seat frame, at a speed of
35 to 45 degrees per second, to an angle of 180
degrees. The rotation shall be stopped when it
reaches that angle and the seat shall be held in this
position for three seconds. The child restraint shall
not fall out of the aircraft safety belt, nor shall the
test dummy fall out of the child restraint at any
time during the rotation or the three second
period. The specified rate of rotation shall be
attained in not less than one half second and not
more than one second, and the rotating combina-
tion shall be brought to a stop in not less than one
half second and not more than one second.

44 F.R. 72131
December 13, 1979

PART 571; S 213-20

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY

STANDARD NO. 214
Side Impact Protection — Light Trucks, Buses, and Multipurpose Passenger

Vehicles

(Docket No. 88-06; Notice 19)
RIN: 2127-AE32

ACTION: Final rule;
reconsideration.

response to petitions for SUPPLEMENTARY INFORMATION:

SUMMARY: On June 14, 1991. NHTSA published
in the Federal Register (56 FR 27427) a final rule
extending the quasistatic side door strength
requirements of Federal Motor Vehicle Safety
Standard No. 214, Side Impact Protection, to
trucks, buses and multipurpose passenger vehicles
with a gross vehicle weight rating of 10,000
pounds or less. The agency established an effec-
tive date of September 1, 1993 for the extension
of these requirements. NHTSA received one peti-
tion for reconsideration of the final rule, from
General Motors (GM). The petitioner requested
that the agency phase-in the new requirements
instead of applying them to all of the newly cov-
ered vehicles simultaneously. In response to GM's
petition, NHTSA is establishing a brief phase-in
period for the new requirements and is delaying
by one year the effective date for double opening
cargo doors, doors with no windows, and certain
contoured doors. The agency notes, however, that
it is adopting a different phase-in schedule from
that suggested by the petitioner. NHTSA is also
establishing the reporting and recordkeeping
requirements necessary for it to enforce the phase-
in. Finally, NHTSA is adopting a phase-in exclu-
sion for vehicles manufactured in two or more
stages and for altered vehicles.

DATES: The amendments in this final rule are
effective September 1, 1993. NHTSA notes, how-
ever, that the amendments to Standard No. 214
have the effect of providing an additional year's
leadtime for certain doors and vehicles.

Background

On June 14, 1991, NHTSA published in the
Federal Register (56 FR 27427) a final rule
extending the quasistatic side door strength
requirements of Federal Motor Vehicle Safety
Standard No. 214, Side Impact Protection, to
trucks, buses and multipurpose passenger vehicles
(MPV's) with a gross vehicle weight rating of
10,000 pounds or less. (These vehicles are collec-
tively referred to as "LTV's.") The agency estab-
lished an effective date of September 1, 1993 for
the extended applicability of the requirements,
thus providing a leadtime of just over two years
from the time of the final rule. Certain side doors,
including ones that are more than a specified dis-
tance away from seats and therefore unlikely to
have vehicle occupants sitting near them, were
excluded from the coverage of the standard.

Standard No. 214's quasi-static requirements,
which have applied to passenger cars since Janu-
ary 1, 1973, seek to mitigate occupant injuries in
side impacts by reducing the extent to which the
side structure of a vehicle is pushed into the pas-
senger compartment during a side impact. The
requirements specify that side doors must resist
crush forces that are applied against the door's
outside surface in a laboratory test. The load is
applied by means of a piston pressing a vertical
steel cylinder against the middle of the door.
Since car manufacturers have generally chosen to
meet the requirements by reinforcing the side
doors with metal beams, the agency expects that
LTV manufacturers will generally do the same.

PART 571: S214-PRE-75

Petition for Reconsideration

NHTSA received one petition for reconsider-
ation of the final rule extending Standard No.
214's quasi-static side door strength requirements
to LTV's, from General Motors (GM). The peti-
tioner requested that, instead of making the
requirements effective for all LTV's on Septem-
ber 1, 1993, the agency provide the following
phase-in: 75 percent of LTV's manufactured in
the production year beginning September 1, 1993,
90 percent of LTV's manufactured in the produc-
tion year beginning September 1. 1994, and 100
percent of LTV's effective September 1, 1995.

GM stated that a phase-in of the requirements
is essential for two reasons. First, that company
noted that the agency has not yet established the
test requirements for double cargo doors and for
doors with no windows. GM stated that until the
test requirements for double cargo doors and
doors without windows are known, it cannot
design the modifications needed to meet the
requirements for those doors. According to the
petitioner, the modifications may include struc-
tural or hardware changes as well as the installa-
tion of side door beams. GM stated that two years
is an absolute minimum leadtime, barely allowing
for validation of the design, and thus leaving
inadequate time for other considerations such as
cost and mass optimization.

GM also argued that because the requirements
for some types of side doors are not yet com-
pleted, manufacturers cannot yet modify a vehicle
to meet the requirements for all available types of
side doors in one design iteration. According to
GM, manufacturers generally implement design
changes on all like models based on the most
severe test requirements. Thus, if GM designed a
particular model with sliding doors to meet Stand-
ard No. 214 and the test requirements for doors
without windows or for double cargo doors later
turned out to have the most severe implications
on product design (e.g., required structural
changes), GM's first redesign would be obsolete.
The company indicated that a phase-in would
help address this concern.

The second reason cited by GM in support of
its argument that a phase-in is needed is the pos-
sible interaction between the requirements of
Standard No. 214 and other safety standards,
especially Standard No. 208, Occupant Crash
Protection. GM argued that such interaction may

require longer leadtime for some vehicles. (Under
Standard No. 208, vehicles must meet specified ^^
injury criteria, including a head injury criterion |^
(HIC), measured on test dummies in frontal bar-
rier crash tests.)

According to GM, side door beams installed to
meet Standard No. 214 can change a vehicle's
frontal barrier performance enough to necessitate
retesting to recertify the vehicles to Standard No.
208 and other standards. The company stated that
the addition of door beams generally stiffens a
vehicle's occupant compartment. While this usu-
ally helps reduce the likelihood of dummy head
contacts in standard No. 208 testing. GM stated
that its experience shows that stiffening the occu-
pant compartment can also increase non-contact
HICs in Standard No. 208 tests, particularly when
using the Hybrid III test dummy (one of two
alternative test dummies specified by the stand-
ard). In a meeting with NHTSA staff concerning
its petition, GM provided data from crash tests for
one model in which the addition of a roof
reinforcement increased HIC from 930 to 1010,
and the further addition of door beams raised HIC
to 1250.

GM stated that the expected modifications for ^
Standard No. 214 will substantially affect the
performance in Standard No. 208 tests only in a
minority of LTV models. The company argued,
however, that some LTV models will likely need
significant changes to achieve adequate perform-
ance in frontal barrier crashes because of crash
pulse changes caused by the installation of side
door beams and that it will not know which mod-
els need such changes until it completes the fron-
tal baiTier tests. GM argued that a phase-in is
needed to provide the longer leadtime it believes
is required to make the necessary design changes
and conduct compliance testing for this group of
LTV's.

The petitioner stated that the first year phase-
in of 75 percent that it recommends would
include all of a manufacturer's LTV's except per-
haps one or two van models that have double
cargo doors or doors without windows for which
test requirements are not yet defined and/or one
or two other LTV models that cannot be
recertified to meet Standard No. 208 by Septem-
ber 1, 1993 if side door beams are added. GM
stated that the second year phase-in of 90 percent %

that it recommends would include all of a manu-
facturer's LTV's except perhaps one small-vol-

PART 571; S214-PRE-76

ume LTV model that cannot yet be recertified to
meet Standard No. 208 if side door beams are
added.

GM also argued that its recommended phase-in
would allow manufacturers to meet the new
requirements with designs that are more opti-
mized for cost and mass, and that are less likely
to degrade other areas of vehicle performance.
The company stated that manufacturers may use
the phase-in to avoid diverting test and design
resources from other important safety and crash-
worthiness projects, such as implementing air
bags in advance of the mandated automatic
restraint phase-in. Finally, GM stated that it
believes that its proposed phase-in is reasonable
and meets the intent of the agency to extend
Standard No. 214's side door strength require-
ments to LTV's promptly and practicably.

While GM was the only petitioner for
reconsideration, Chrysler submitted a letter
strongly urging that NHTSA grant 's petition and
adopt the phase-in schedule recommended by
GM. Chrysler stated that it shared GM's concern
that the test requirements for double-opening side
cargo doors and doors without windows will not
be available in time for it to meet the require-
ments by September 1, 1993. That company
stated that while it does not manufacture any full-
size vans/wagons with such doors which are suffi-
ciently close to seats to be covered by the stand-
ard, it manufactures many such vans with those
types of doors that are sold to van converters who
do install seats close to the doors. Chrysler stated
that it therefore expects to be asked to provide
vehicles that meet door crush requirements to
these final stage manufacturers so that they can
take advantage of "pass-through" certification.
Also, Ford Motor Company expressed its support
for a brief phase-in, in a meeting with Department
officials.

Summary of Amendments Being Made in
Response to GM's Petition

In response to GM's petition, NHTSA is
amending Standard No. 214 in several respects.
First, the agency is establishing a brief phase-in
for the newly-extended requirements. For the
production year beginning September 1, 1993, 90
percent of a manufacturer's LTV's will be
required to meet the new requirements; 100 per-
cent compliance will be required effective
September 1, 1994. Second, NHTSA is delaying

by one year, to September 1, 1994, the effective
date of the requirements for double opening cargo
doors and doors with no windows, since the test
procedure for these doors has not yet been estab-
lished. The agency is also delaying the effective
date for certain contoured doors, since it has
determined that the test procedure for these doors
also needs clarification.

Since NHTSA is adopting a phase-in, it is also
establishing the reporting and recordkeeping
requirements necessary for the agency to enforce
the phase-in. Similar requirements have been
adopted by the agency as an integral part of its
phase-ins of other major new safety requirements.
Finally, the agency is adopting a phase-in exclu-
sion for vehicles manufactured in two or more
stages and for altered vehicles.

Response to GM's Petition

Several commenters on NHTSA's proposal to
extend Standard No. 214's side door strength
requirements to LTV's requested a phase-in of the
requirements. In the preamble to the June 1991
final rule, the agency addressed the related issues
of leadtime and the appropriateness of a phase-in
as follows:

"After considering [the] comments and other
information, NHTSA has decided to make the
new requirements effective on September 1,
1993. NHTSA has concluded that manufactur-
ers need this time period to equip all LTV's
with side door beams as standard equipment
after the necessary design, tooling, and testing.
In addition, final-stage manufacturers need this
much time to decide how to certify compliance
with the requirements. * * *

"NHTSA does not believe that additional
leadtime or a phase-in is necessary. Door beam
technology has been used with passenger cars
since 1973. Further, a few LTV's are currently
manufactured with side door beams. While
Ford initially asserted that the installation of
side door beams in one of its models would
require major design changes. Ford has since
developed a beam design which can be
installed in the door of the specific model with-
out a major design change." 56 FR 27436.
After considering GM's petition for reconsider-
ation, however, NHTSA has concluded that GM's
two primary arguments have merit and warrant
changes in the standard's effective date. The
agency's analysis of GM's arguments and a

PART 571; S214-PRE-77

discussion of the changes being made in response
to those arguments follow.

NHTSA agrees with GM's first main argument
that the lack of test procedures for double-open-
ing cargo doors and doors without windows
makes it impossible for manufacturers to com-
plete the necessary design modifications for these
doors. The agency indicated in the June 1991
final rule that it expected "in the near future" to
propose amendments to address test procedures
for these doors. However, the development of the
proposal took longer than expected, and it was
not published until January 15. 1992, with a com-
ment closing date of March 16, 1992. See 57 FR
1716. Thus, the continuing lack of test procedures
for these doors has cut much farther into the two-
year leadtime period than expected. Assuming
that a final rule is issued this summer or early
Fall, the remaining leadtime would be little more
than one year.

In order to ensure that the "practicability"
requirements of the National Traffic and Motor
Vehicle Safety Act are met and that manufactur-
ers have sufficient leadtime for the necessary
design, tooling, and testing of double-opening
cargo doors and doors without windows, NHTSA
has decided to extend the effective date for these
doors by one year, to September 1, 1994. Assum-
ing that the agency publishes a final rule concern-
ing the test procedures some time this summer or
early Fall, this will provide manufacturers with
approximately two years leadtime for these doors.

NHTSA does not believe that GM's argument
about its desire to modify all like models based
on the most severe test requirements justifies
relief beyond providing additional leadtime for
the types of doors for which test procedures have
not yet been established. First, even in the
absence of the details of the test procedure, the
agency believes that the performance require-
ments set forth in Standard No. 214 for double-
opening cargo doors and doors without windows
are sufficient for manufacturers to determine
whether structural or other changes beyond add-
ing a door beam will be required. Therefore,
manufacturers should be able to determine
whether these doors represent the most severe test
requirement for a particular model and design
other types of doors for the same model with that
in mind, thereby avoiding a need for more than
one design iteration. Second, given the safety
benefits associated with this ailemaking, the

agency believes that it would be inappropriate to
delay application of the standard to types of doors
for which design changes can easily be made ^^
merely to facilitate future compliance for other ^^
types of doors.

As discussed in the January 1992 notice of pro-
posed rulemaking (NPRM) concerning test proce-
dures for double-opening cargo doors and doors
without windows, NHTSA has determined that
clarification of the test procedure is also needed
for certain contoured doors. The NPRM therefore
proposed amendments to clarify the test procedure
for contoured doors.

Standard No. 214's test procedure works well
when a door's lower edge is essentially horizontal
along its entire length, or only a small portion of
the door's lower edge deviates from that descrip-
tion by being contoured upward. Almost all pas-
senger cars have doors of these types. However,
as discussed in the January 1992 NPRM, the
standard's test procedure is not appropriate when
only a small portion of a door's lower edge is
horizontal and the edge is contoured significantly
upwards for a large part of the door. Some LTV's
have such doors. Since, in the absence of clarify-
ing amendments concerning test procedures, these
doors pose similar difficulties concerning compli- ^^
ance as those for double-opening cargo doors and
doors without windows, NHTSA is also extending
the effective date for these doors to September 1,
1994.

After reviewing the infonnation submitted by
GM in support of its petition, NHTSA is also per-
suaded that the possible interaction between the
requirements of Standard No. 214 and other
safety standards, particularly Standard No. 208,
may require longer leadtime for a few vehicles.

As indicated above, NHTSA concluded in the
June 1991 final rule that manufacturers required
about two years leadtime for the design, tooling
and testing necessary to meet the new require-
ments, and that additional leadtime was not
needed in light of the time side door beam tech-
nology has been used for passenger cars. The
two-year period did not, however, account for the
possibility that a few vehicles, after being
redesigned for Standard No. 214, might require
further redesign to ensure that they continue to
meet the dynamic test requirements of Standard
No. 208. ^

NHTSA does not consider it likely, for a ^

particular LTV, that the addition of side door

PART 571; S2I4-PRE-78

beams would increase HIC in Standard No. 208
testing. The occupant compartments of LTV's are
generally stiffer than those of passenger cars, and
any incremental stiffness that may result from the
addition of side door beams is likely to be
extremely small. Further, as indicated by GM, the
stiffening of a vehicle's occupant compartment
usually reduces the likelihood of dummy head
contacts in frontal crash tests. For most current
vehicles, this would be expected to reduce HIC.
In addition, even if the addition of side door
beams did slightly raise noncontact HIC, this
would only affect the compliance of vehicles with
Standard No. 208 if the vehicles previously only
marginally complied with the standard. The
agency believes that the small possibility of a
particular vehicle's HIC being increased by the
addition of side door beams is demonstrated by
the fact that no other manufacturer has presented
information to the agency concerning the prob-
lem. Further, GM, in responding to the agency's
request for data concerning this problem, provided
data for only one vehicle.

NHTSA agrees, however, that the test data pre-
sented by GM demonstrate that the addition of
side door beams may, for a few vehicles, suffi-
ciently affect HIC that further redesign will be
necessary to ensure that the vehicles continue to
meet Standard No. 208.

The agency has therefore decided to establish a
brief phase-in for the new requirements. Accord-
ingly, for the production year beginning Septem-
ber 1, 1993, 90 percent of a manufacturer's
LTV's will be required to meet the new require-
ments; 100 percent compliance will be required
effective September 1, 1994. Thus, the agency is
providing an extra year's leadtime for up to 10
percent of a manufacturer's production of LTV's.

NHTSA believes that the phase-in being
adopted will provide sufficient flexibility to cover
the possibility that the compliance of a few
LTV's with Standard No. 208 could be affected
by the addition of side door beams and therefore
need further redesign. The agency has carefully
reviewed the information provided by GM and
does not believe that the number of vehicles that
could be affected would exceed 10 percent of that
company's annual LTV production. Further, given
the small number of vehicles, if any, that would
be involved, the agency believes that an addi-
tional year's leadtime is ample for a manufacturer
to make any additional changes necessary to

ensure continuing compliance with Standard No.
208. Finally, given the fact that the delay in
effective date affects no more than 10 percent of
a manufacturer's LTV production for a single
year and that it appears that not all manufacturers
would avail themselves of the phase-in, any
reduction in safety benefits is minimized.

NHTSA notes that it is not adopting the spe-
cific phase-in recommended by the petitioner, i.e.,
75 percent of LTV's for the production year
beginning September 1, 1993, and 90 percent of
LTV's for the following year. The agency
believes, for the reasons stated above, that the
combination of delaying the effective date for
double-opening cargo doors and doors without
windows and the one-year phase-in adequately
addresses the concerns raised by GM's two main
arguments.

As indicated above, GM also asserted that its
recommended phase-in would allow manufactur-
ers to meet the new requirements with designs
that are more optimized for cost and mass and
that are less likely to degrade other areas of
vehicle performance. That company also asserted
that manufacturers may use the phase-in to avoid
diverting test and design resources from other
important safety and crashworthiness projects,
such as implementing air bags in advance of the
mandated automatic restraint phase-in. However,
GM did not provide any evidence demonstrating
that additional leadtime, beyond that provided by
this final rule, is needed for design optimization
or would result in any safety benefits by facilitat-
ing design improvements in other areas. In the
absence of such evidence and given the reduced
safety benefits that could result from a longer
phase-in, the agency does not believe that a
longer phase-in is appropriate.

In the NPRM proposing to extend the side door
strength requirements of Standard No. 214 to
LTV's, the agency requested that any commenters
supporting a leadtime longer than two years
address whether such longer leadtime is needed
for all vehicles or whether the proposed amend-
ments could be phased in for some vehicles at an
earlier time. See 54 FR 52832, December 22,
1989. The agency thus addressed in the NPRM
the possibility of a phase-in. Several commenters,
including GM, Ford and the Motor Vehicle
Manufacturers Association, supported a phase-in.
Ford requested that the agency adopt in any final
rule, provisions such as those in Standard No. 208

PART 571; S214-PRE-79

for production volumes, carryforward credits, and
cars produced by more than one manufacturer.

While NHTSA did not discuss in the NPRM
the specific requirements that would be associated
with a phase-in, the agency has addressed that
issue in three other rulemakings: (1) the establish-
ment of Standard No. 208 's automatic crash
protection requirements for cars, (2) the extension
of those requirements to LTV's, and (3) the
establishment of Standard No. 214"s dynamic side
impact protection requirements for cars. In each
case, for example, reporting and recordkeeping
requirements have been integral parts of the
phase-ins. Given that the agency raised the
possibility of a phase-in in the NPRM and the
general understanding commenters had concerning
how the agency implemented phase-ins in other
rulemakings, NHTSA believes that the establish-
ment of specific phase-in requirements along the
lines of those in Standard No. 208 and Standard
No. 214 (dynamic side impact requirements for
passenger cars) are within the scope of notice for
this rulemaking.

As suggested by Ford in its comment on the
NPRM, the agency is including provisions similar
to those in Standard No. 208 for production vol-
umes and vehicles produced by more than one
manufacturer. As in the case of the agency's
phase-in of Standard No. 214's dynamic require-
ments for passenger cars, NHTSA is not, how-
ever, including the provisions for carry-forward
credits. The purpose of the limited phase-in
adopted in response to GM's petition is to pro-
vide an additional year's leadtime for up to 10
percent of a manufacturer's LTV production.
Carryforward credits are unnecessary to meet this
purpose. Further, some LTV's already meet the
requirements of Standard No. 214, and a provi-
sion permitting manufacturers to count such
vehicles toward the 90 percent one-year require-
ment could unnecessarily dilute that requirement,
resulting in reduced safety benefits.

NHTSA is also establishing the reporting and
recordkeeping requirements necessary for the
agency to enforce the phase-in. The requirements
are similar to those adopted for Standards No.
208 and No. 214, although only a single report is
required since the phase-in is for one year. For a
further explanation of the agency's rationale for
the specific requirements, see the preamble to the
final rule establishing those requirements for the
phase-in of Standard No. 214's dynamic require-

ments for passenger cars (56 FR 43768, October

30, 1990). _

As the agency recognized for the phase-in of ^^
Standard No. 208 's automatic restraint require-
ments for LTV's, a phase-in of requirements for
LTV's has the possibility of creating significant
problems for many final stage manufacturers and
alterers. Like other manufacturers, final stage
manufacturers and alterers must certify that their
vehicles meet all applicable safety standards.
Many of these manufacturers are small businesses
and typically complete or modify vehicles based
on instructions from the major manufacturers, as
a basis for certification.

The potential problems that could be caused by
applying a phase-in requirement to these manu-
facturers can be illustrated by considering the
case of a van converter which purchases vans
from GM, Ford or Chrysler and then alters them
for the specialty market. If the one-year 90 per-
cent phase-in requirement were applied to van
converters, each van converter would need to
ensure that 90 percent of the vans it altered com-
plied with Standard No. 214. However, many van
converters are very small and only alter a few
vans each year. If the vehicles a particular van ^

converter wanted to alter happened to be ones for ^^

which GM, Ford or Chrysler determined that the
extra year's leadtime permitted by the phase-in
was needed, it is highly unlikely the van con-
verter could make the necessary design changes
to those vehicles to certify that they would meet
Standard No. 214.

In light of the potential problems that the
phase-in could cause for final stage manufacturers
and alterers, NHTSA is excluding LTV's manu-
factured in two or more stages and LTV's that are
altered from Standard No. 214's requirements
during the phase-in. This is the same approach
that the agency followed for the phase-in of
Standard No. 208 's automaUc crash protection
requirements for LTV's. See 56 FR 12479-80,
March 26, 1991. Because of this exclusion, this
rule also permits original manufacturers the
option to either include or exclude their LTV's
that are sent to second stage manufacturers and
alterers, when determining compliance during the
phase-in for Standard No. 214.

This final rule does not have any retroactive
effect. Under section 103(d) of the National Traf- ^

fie and Motor Vehicle Safety Act (15 U.S.C. ^

1392(d)), whenever a Federal motor vehicle safety

PART 571; S214-PRE-80

standard is in effect, a state may not adopt or
maintain a safety standard applicable to the same
aspect of performance which is not identical to
the Federal standard. Section 105 of the Act (15
U.S.C. 1394) sets forth a procedure for judicial
review of final rules establishing, amending or
revoking Federal motor vehicle safety standards.
That section does not require submission of a
petition for reconsideration or other administrative
proceedings before parties may file suit in court.
In consideration of the foregoing. Parts 57 1 and
586 of Title 49 of the Code of Federal Regula-
tions are amended as follows:

Part 571— [AMENDED]

1. The authority citation for Part 571 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401. 1403, 1407;
delegation of authority at 49 CFR 1.50.

2. In S571.214, S2.1, as added at 56 FR 27437,
June 14, 1991, effective September 1, 1993, is
revised to read as follows:

S2.1. Definitions.

Double cargo doors means a pair of hinged
doors with the lock and latch mechanisms located
where the door lips overlap.

Walk-in van means a van in which a person can
enter the occupant compartment in an upright
position.

3. In S571.214, S3, as revised at 56 FR 27437,
June 14, 1991, effective September 1, 1993, is
amended by revising S3(a) and adding new
S3(e)(5) through S3(e)(7) to read as follows:

S3. Requirements, (a)(1) Except as provided
in section S3(e), each passenger car shall be able
to meet the requirements of either, at the manufac-
turer's option, S3.1 or S3.2, when any of its side
doors that can be used for occupant egress is
tested according to S4.

(2) Except as provided in section S3(e), each
multipurpose passenger vehicle, truck and bus
manufactured on or after September 1, 1994 shall
be able to meet the requirements of either, at the
manufacturer's option, S3.1 or S3. 2, when any of
its side doors that can be used for occupant egress
is tested according to S4.

(3) Except as provided in section S3(e), from
September 1, 1993 to August 31, 1994, at least 90
percent of each manufacturer's combined yearly
production of multipurpose passenger vehicles.

trucks and buses with a GVWR of 10.000 pounds
or less, as set forth in S9, shall be able to meet
the requirements of either, at the manufacturer's
option, S3.1 or S3. 2, when any of its side doors
that can be used for occupant egress is tested
according to S4.

(e) * * *

(5) for multipurpose passenger vehicles, trucks,
and buses manufactured before September 1,
1994, any double cargo doors.

(6) for multipurpose passenger vehicles, trucks,
and buses manufactured before September 1,
1994, any doors without one or more windows.

(7) for multipurpose passenger vehicles, trucks,
and buses manufactured before September 1,
1994, any doors for which the ratio of the width
of the lowest portion of the door to the width of
the door at its widest point is not greater than 0.5.
The width of the door is measured in a horizontal
plane and on the outside surface of the door. The
lowest portion of the door is that portion of the
lower edge of the door which is lowest to the
ground and which is essentially horizontal.

4. In S571.214, S9 through S9.2.3 are added to
read as follows:

S9. Phase-in of side door strength require-
ments for multipurpose passenger vehicles,
trucks and buses.

S9.1 Multipurpose passenger vehicles, trucks
and buses manufactured on or after Septem-
ber 1, 1993 and before September 1, 1994.

S9.1.1 The combined number of multipurpose
passenger vehicles, trucks and buses with a
GVWR of 10,000 pounds or less complying with
the requirements of S3(a)(3) shall not be less than
90 percent of:

(a) The average annual production of multipur-
pose passenger vehicles, trucks and buses with a
GVWR of 10,000 pounds or less manufacmred on
or after September 1, 1990 and before September
1, 1993 by each manufacturer, or

(b) The manufacturer's annual production of
multipurpose passenger vehicles, trucks and buses
with a GVWR of 10,000 pounds or less during
the period specified in S9.1.

PART 571; S214-PRE-81

S9.1.2 Walk-in vans, vehicles which do not have
any side doors that can be used for occupant
egress, vehicles which exclusively have doors of
the types specified in S3(e), and vehicles specified
in S9.2.3 may be excluded from all calculations of
compliance with S9.1.1.

S9.2 Multipurpose passenger vehicles, trucks
and buses produced by more than one manu-
facturer.

59.2.1 For the purposes of calculating average
annual production of multipurpose passenger
vehicles, trucks and buses with a GVWR of
10,000 pounds or less for each manufacturer and
the number of multipurpose passenger vehicles,
trucks and buses with a GVWR of 10.000 pounds
or less manufactured by each manufacturer under
S9.1.1, a vehicle produced by more than one
manufacturer shall be attributed to a single manu-
facturer as follows, subject to S9.2.2:

(a) A vehicle which is imported shall be attrib-
uted to the importer.

(b) A vehicle manufactured in the United States
by more than one manufacturer, one of which
also markets the vehicle, shall be attributed to the
manufacturer which markets the vehicle.

59.2.2 A vehicle produced by more than one
manufacturer shall be attributed to any one of the
vehicle's manufacturers specified by an express
written contract, reported to the National Highway
Traffic Safety Administration under 49 CFR Part
586, between the manufacturer so specified and
the manufacturer to which the vehicle would
otherwise be attributed under S9.2. 1 .

59.2.3 Each multipurpose passenger vehicle, truck
and bus with a GVWR of 10,000 pounds or less
that is manufactured in two or more stages or that
is altered (within the meaning of S567.7 of this
chapter) after having previously been certified in
accordance with Part 567 of this chapter is not
subject to the requirements of S3(a)(3).

Part 586 [AMENDED]

5. The authority citation for Part 586 continues
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1407; delega-
tion of authority at 49 CFR Part 1 .50.

6. Section 586.1 is revised to read as follows:

5586.1 Scope.

This part establishes requirements for passenger
car manufacturers to submit a report, and main- ^
tain records related to the report, concerning the ^
number of passenger cars manufactured that meet
the dynamic test procedures and performance
requirements of Standard No. 214, Side Impact
Protection (49 CFR 571.214), and it establishes
requirements for manufacturers of multipurpose
passenger vehicles, trucks and buses with a gross
vehicle weight rating (GVWR) of 10,000 pounds
or less to submit a report, and maintain records
related to the report, concerning the number of
such vehicles that meet the side door strength
requirements of Standard No. 214.

7. Section 586.2 is revised to read as follows:

5586.2 Purpose.

The purpose of the reporting requirements is to
aid the National Highway Traffic Safety Adminis-
tration in determining whether a passenger car
manufacturer has complied with the requirements
of Standard No. 214, Side Impact Protection (49
CFR 571.214) concerning dynamic test proce-
dures and performance requirements concerning
side impact protection, and whether a manufac-
turer of multipurpose passenger vehicles, trucks ^
and buses with a GVWR of 10,000 pounds or less "
has complied with the side door strength require-
ments of Standard No. 214.

8. Section 586.3 is revised to read as follows:

5586.3 Applicability.

This part applies to manufacturers of passenger
cars and to manufacturers of multipurpose pas-
senger vehicles, trucks and buses with a GVWR
of 10,000 pounds or less. However, this part does
not apply to any manufacturers of multipurpose
passenger vehicles, trucks and buses whose
production consists exclusively of walk-in vans,
vehicles which do not have any side doors that
can be used for occupant egress, vehicles which
exclusively have doors of the types specified in
S3(e) of 49 CFR 571.214, vehicles manufactured
in two or more stages, and vehicles that are
altered after previously having been certified in
accordance with Part 567 of this chapter.

9. Section 586.4 is amended by revising para-
graph (b) to read as follows:

5586.4 Definitions. ▲

PART 571; S214-PRE-82

(b) Bus, gross vehicle weight rating or GVWR,
multipurpose passenger vehicle, passenger car,
and truck are used as defined in S571.3 of this
chapter.

10. Section 586.5 is amended by revising the
heading to read as follows:

S586.5 Reporting requirements — manufactur-
ers of passenger cars.

11. Section 586.6 is amended by revising the
heading to read as follows:

S586.6 Records— passenger cars.

12. Section 586.7 is redesignated as section
586.9 and revised to read as follows:

S586.9 Petition to extend period to file report.

A petition for extension of the time to submit
a report must be received not later than 15 days
before expiration of the time stated in § 586.5(a)
or §586.7 (a). The petition must be submitted to:
Administrator. National Highway Traffic Safety
Administration, 400 Seventh Street, S.W.,
Washington, D.C. 20590. The filing of a petition
does not automatically extend the time for filing
a report. A petition will be granted only if the
petitioner shows good cause for the extension and
if the extension is consistent with the public
interest.

13. Sections 586.7 and 586.8 are added to read
as follows:

S586.7 Reporting requirements— manufactur-
ers of trucl<s, buses and multipurpose pas-
senger vehicles.

(a) General reporting requirements. Within 60
days after the end of the production year ending
August 31, 1994, each manufacturer shall submit
a report to the National Highway Traffic Safety
Administration concerning its compliance with the
requirements of S3(a) of Standard No. 214 for its

tmcks, buses and multipurpose passenger vehicles
produced in that year. Each report shall —

(1) Identify the manufacturer;

(2) State the full name, title, and address of the
official responsible for preparing the report;

(3) Contain a statement regarding whether or
not the manufacturer complied with S3(a)(3) of
Standard No. 214 and the basis for that statement;

(4) Provide the information specified in
§ 586.7(b);

(5) Be written in the English language; and

(6) Be submitted to: Administrator, National
Highway Traffic Safety Administration, 400 Sev-
enth Street, SW., Washington, DC 20590.

(b) Report content — (1) Basis for phase-in
production goals. Each manufacturer shall provide
the number of trucks, buses and multipurpose pas-
senger vehicles with a GVWR of 10,000 pounds
or less manufactured for sale in the United States
for each of the three previous production years,
or, at the manufacturer's option, for the current
production year. A new manufacturer that has not
previously manufactured trucks, buses and multi-
purpose passenger vehicles with a GVWR of
10.000 pounds or less for sale in the United
States must report the number of such vehicles
manufactured during the current production year.

(2) Production. Each manufacturer shall report
the number of multipurpose passenger vehicles,
trucks and buses with a GVWR of 10,000 pounds
or less that meet the side door strength require-
ments (S3.1 or S3.2) of Standard No. 214.

(3) Vehicles produced hy more than one manu-
facturer. Each manufacturer whose reporting of
information is affected by one or more of the
express written contracts permitted by 59.2.2 of
Standard No. 214 shall:

(i) Report the existence of each contract,
including the names of all parties to the contract,
and explain how the contract affects the report
being submitted.

(ii) Report the actual number of vehicles cov-
ered by each contract.

PART 571; S214-PRE-83

S586.8 Records— multipurpose passenger Issued on: July 7 1992.

vehicles, trucks and buses. Frederick H. Grubbe,

Each manufacturer shall maintain records of the Deputy Administrator ^

Vehicle Identification Number for each multipur- 57 F R 10917 ^^

pose passenger vehicle, truck and bus for which . . ^, iqaj^
information is reported under § 586.7(b)(2) until
December 31, 1996.

PART 571; S214-PRE-

PREAMBLE TO AN AMENDMENT TO
FEDERAL MOTOR VEHICLE SAFETY STANDARD NO.
Side Impact Protection

(Docket No. 88-06, Notice 17)
RIN 2127-AE05

214

ACTION: Final rule; corrections.

SUMMARY: On September 17, 1991, NHTSA
published in the Federal Register a final rule
which corrected minor errors in the agency's
October 1990 final rules concerning dynamic side
impact requirements for passenger cars. The final
rule also established an effective date for side
impact phase-in reporting requirements. Today's
final rule corrects two errors that were made in the
September 17, 1991 final rule. First, Figure 2 of
Standard No. 214, Side Impact Protection, which
provides a schematic of the moving deformable
barrier used in the dynamic side impact test, is
corrected to include certain specifications that
were inadvertently omitted. Second, the final rule
establishes an effective date for certain of the side
impact phase-in reporting requirements that were
inadvertently not covered by the September 1991
final rule.

DATES: Effective Date: The amendments in this
document and § 586.5, published at 55 FR 45770
on October 30, 1990, are effective June 22, 1992.

SUPPLEMENTARY INFORMATION: On October
30, 1990, NHTSA published in the Federal Reg-
ister (55 FR 45722) a final rule adding dynamic
test procedures and performance requirements to
Standard No. 214, Side Impact Protection. The
dynamic test requirements of Standard No. 214
are phased in over a three-year period, beginning
on September 1, 1993. At the same time, NHTSA
also published final rules: (1) establishing the
specifications for the side impact dummy to be
used in the dynamic crash test (55 FR 45757), (2)
establishing the attributes of the moving deform-
able barrier (MDB) to be used in the dynamic
crash test (55 FR 45770), and (3) establishing the
reporting and recordkeeping requirements nec-
essary for NHTSA to enforce the phase-in of the
new dynamic requirements.

On September 17, 1991, NHTSA published in
the Federal Register (56 FR 47007) a final rule
which corrected minor errors in the October 1990
final rules. The final rule also amended the regu-
lation establishing reporting and recordkeeping
requirements, 49 CFR part 586, Side Impact
Phase-In Reporting Requirements, to establish an
effective date for the regulation's information
collection requirements and to add the Office of
Management and Budget (OMB) approval number
assigned under the Paperwork Reduction Act.

Ford submitted a petition for reconsideration of
the September 17, 1991 final rule, expressing
concern that in revising the schematic of the
MDB used in the dynamic side impact test (Fig-
ure 2 of Standard No. 214), NHTSA omitted
specifications for face plate thickness, material
strength, and aluminum alloy that were included
in the earlier version of the schematic. That com-
pany stated that if the omission of the specifica-
tions was inadvertent, its letter should be consid-
ered a request for correcting the specifications
promptly so that the existing ambiguity is elimi-
nated.

In a letter dated December 17, 1991, NHTSA
advised Ford that the omission of the specifica-
tions in the schematic of the MDB was inadvert-
ent and that the agency planned to publish a
correction notice. Today's final rule corrects Fig-
ure 2 of Standard No. 214 by adding the speci-
fications that were inadvertently omitted in the
September 17, 1991 final rule.

NHTSA is also setting an effective date for
§ 586 of part 586. That section was inadvertently
not made effective in the September 1991 final
rule. In addition, in order to make part 586
consistent with the rest of NHTSA' s regulations,
the agency is removing the OMB control number
from §586.6. It is NHTSA's standard practice to
publish the OMB control numbers for all of its
regulations in a single place, 49 CFR part 509,

PART 571; S214-PRE-85

0MB Control Numbers for Information Collection
Requirements.

Today's amendments are effective 30 days after
publication of this document in the Federal Reg-
ister. The amendments are merely technical
corrections of the final rule that was published on
September 17, 1991, which itself made technical
corrections of final rules published on October 30,
1990. Today's amendments do not impose any
new substantive requirements. Therefore, NHTSA
finds for good cause that notice and comment on
these amendments are unnecessary. Because of
the non-substantive nature of the amendments,
NHTSA also finds for good cause that making the
rule 30 days after publication is in the public
interest.

In consideration of the foregoing, 49 CFR parts
571 and 586 are amended as follows:

Figure 2 of §571.214 is revised as follows:

Part 586— [Amended] |r

3. The authority section for part 586 continues ^*
to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1407; delega-
tion of authority at 49 CFR 1.50.

§586.6 [Amended]

4. Section 586.6 is amended by removing the
parenthetical at the end of the section.

Issued on May 14, 1992.

Jerry Ralph Curry,
Administrator.

57 F.R. 21613
May 21, 1992

Part 571— [Amended]

1. The authority section for part 571 continues
to read as follows:

PART 5 71; S214-PRE-86

74"

143"
102"

■BARRIER
FACE

TOP

VIP//

RIGHT
SIDE
VIEW

1 -Piece Alum. Honey-
comb Block - - 45 psi
± 2.5 psi crush strength -,

r 0.032" Alum. Back /
Plate. 26 ksi 5052- /

NHTSA VEHICLE SIMULATOR

Alum. Honeycomb Bumper, 245 psi ± 15 psi crush strength
0.032" Alum. Face. 26 ksi 5052-H34
- A 66"

NHTSA BARRIER FACE
0.125" Alum. Faces, 50 ksi 2024-T3

SECTION A-A

Figure 2 — NHTSA Side Impactor — Moving Deformable Barrier

PART 571; S214-PRE-87

MOTOR VEHICLE SAFETY STANDARD NO. 214

Side Impact Protection
(Docket No. 2-6; Notice No. 3)

51 Purpose and scope.

(a) Scope. This standard specifies performance
requirements for protection of occupants in side
impact crashes.

(b) Purpose. The purpose of this standard is to
reduce the risk of serious and fatal injury to occu-
pants of passenger cars in side impact crashes by
specifying vehicle crashworthiness requirements
in terms of accelerations measured on
anthropomorphic dummies in test crashes, by
specifying strength requirements for side doors,
and by other means.

52 Applicability. This standard applies to pas-
senger cars. Effective September 1, 1993, sections
S3(a), S3(e), S3.1 through S3.2.3, and S4 of the
standard apply to multipurpose passenger vehicles,
trucks, and buses with a GVWR of 10,000 pounds
or less, except for walk-in vans.

S2.1 Definitions.

Walk-in van means a van in which a person can
enter the occupant compartment in an upright
position.

Wouble cargo doors means a pair of hinged
doors with the lock and mechanisms located
where the door lips overlap. (57 F.R. 30917— July
13, 1992. Effective: September 1, 1993.)]

53 Requirements. (a)[(l)] Except as provided
in section S3(e), each [passenger car] shall be
able to meet the requirements of either, at the
manufacturer's option, S3.1 or S3. 2, when any of
its side doors that can be used for occupant egress
are tested according to S4.

[(2) Except as provided in section S3(e),
each multipurpose passenger vehicle, truck and
bus manufactured on or after September 1,
1994, shall be able to meet the requirements of
either, at the manufacturer's option, S3.1 or
S3.2, when any of its side doors that can be
used for occupant egress is tested according to
S4.

[(3) Except as provided in section S3(e),
from September 1, 1993 to August 31, 1994, at
least 90 percent of each manufacturer's com-
bined yearly production of multipurpose pas-
senger vehicles, trucks and buses with a
GVWR of 10,000 pounds or less, as set forth
in S9, shall be able to meet the requirements of
either, at the manufacturer's option, S3.1 or
S3.2, when any of its side doors that can be
used for occupant egress is tested according to
S4. (57 F.R. 30917— July 13, 1992. Effective:
September 1, 1993.)]

(b) When tested under the conditions of S6,
each passenger car manufactured on or after
September 1, 1996, shall meet the requirements of
S5.1 S5.2, and S5.3 in a 33.5 miles per hour
impact in which the car is struck on either side
by a moving deformable barrier. Part 572, Sub-
part F test dummies are placed in the front and
rear outboard seating positions on the struck side
of the car. However, the rear seat requirements do
not apply to passenger cars with a wheelbase
greater than 130 inches, or to passenger cars
which have rear seating areas that are so small
that the Part 572, Subpart F dummies cannot be
accommodated according to the positioning proce-
dure specified in S7.

(c) Except as provided in paragraph (d) of this
section, from September 1, 1993 to August 31,
1996, a specified percentage of each manufactur-
er's yearly passenger car production, as set forth
in S8, shall, when tested under the conditions of
S6, meet the requirements of S5.1, S5.2, and S5.3
in a 33.5 miles per hour impact in which the car
is struck on either side by a moving deformable
barrier. Part 572, Subpart F test dummies are
placed in the front and rear outboard seating posi-
tions on the struck side of the car. However, the
rear seat requirements do not apply to passenger
cars with a wheelbase greater than 130 inches, or
to passenger cars which have rear seating areas
that are so small that the Part 572, Subpart F
dummies cannot be accommodated according to
the positioning procedure specified in S7.

PART 571; 214-1

(Rev. 7/13/92)

(d) A manufacturer may, at its option, comply
with the requirements of this paragraph instead of
paragraph (c) of this section. When tested under
the conditions of S6, each passenger car manufac-
tured from September 1, 1994 to August 31,
1996, shall meet the requirements of S5.1, S5.2,
and S5.3 in a 33.5 miles per hour impact in which
the car is struck on either side by a moving
deformable barrier. Part 572, Subpart F test dum-
mies are placed in the front and rear outboard
seating positions on the struck side of the car.
However, the rear seat requirements do not apply
to passenger cars with a wheelbase greater than
130 inches, or to passenger cars which have rear
seating areas that are so small that the Part 572,
Subpart F dummies cannot be accommodated
according to the positioning procedure specified
inS7.

(e) A vehicle need not meet the requirements
of sections S3.1 or S3. 2 for —

(1) any side door located so that no point on
a ten-inch horizontal longitudial line passing
through and bisected by the H-point of a mani-
kin placed in any seat, with the seat adjusted
to any position and the seat back adjusted as
specified in section S6.4, falls within the trans-
verse, horizontal projection of the door's open-
ing;

(2) any side door located so that no point on
a ten-inch horizontal longitudinal line passing
through and bisected by the H-point of a mani-
kin placed in any seat recommended by the
manufacturer for installation in a location for
which seat anchorage hardware is provided,
with the seat adjusted to any position and the
seat back adjusted as specified in section S6.4,
falls within the transverse, horizontal projection
of the door's opening;

(3) any side door located so that a portion of
a seat, with the seat adjusted to any position
and the seat back adjusted as specified in sec-
tion S6.4, falls within the transverse, horizontal
protection of the door's opening, but a longitu-
dinal vertical plane tangent to the outboard side
of the seat cushion is more than 10 inches from
the innermost point on the inside surface of the
door at a height between the H-point and
shoulder reference point (as shown in Figure 1
of Federal Motor Vehicle Safety Standard No.
210) and longitudinally between the front edge
of the cushion with the seat adjusted to its
forwardmost position and the rear edge of the

cushion with the seat adjusted to its rearmost
position; or

(4) any side door that is designed to be eas- ^L
ily attached to or removed (e.g., using simple
hand tools such as pliers and/or a screw driver)
from a motor vehicle manufactured for oper-
ation without doors.

[(5) For multipurpose passenger vehicles,
trucks, and buses manufactured before Septem-
ber 1, 1994, any double cargo doors.

(6) For multipurpose passenger vehicles,
trucks, and buses manufactured before Septem-
ber 1, 1994, any doors without one or more
windows.

(7) For multipurpose passenger vehicles,
trucks, and buses manufactured before Septem-
ber 1, 1994, any doors for which the ratio of
the width of the lowest portion of the door to
the width of the door at its widest point is not
greater than 0.5. The width of the door is
measured in a horizontal plane and on the out-
side surface of the door. The lowest portion of
the door is that portion of the lower edge of the
door which is lowest to the ground and which
is essentially horizontal. (57 F.R. 30917— July

13, 1992. Effective: September 1, 1993.)] %

53.1 With any seats that may affect load upon or
deflection of the side of the vehicle removed from
the vehicle, each vehicle must be able to meet the
requirements of S3. 1.1 through S3. 1.3.

53.1.1 Initial Crush Resistance. The initial
crush resistance shall be not less than 2,250
pounds.

53.1.2 Intermediate Crush Resistance. The

intermediate crush resistance shall not be less than
3,500 pounds.

53.1.3 Peak crush resistance. The peak crush
resistance shall not be less than two times the curb
weight of the vehicle or 7,000 pounds, whichever
is less.

53.2 With seats installed in the vehicle, and
located in any horizontal or vertical position to
which they can be adjusted and at any seat back
angle to which they can be adjusted, each vehicle A
must be able to meet the requirements of S3.2.1 ^
through S3. 2.3.

(Rev. 7/13/92)

PART 571; 214-2

53.2.1 Initial crush resistance. The initial crush
resistance shall not be less than 2,250 pounds.

53.2.2 Intermediate crush resistance. The

intermediate crush resistance shall not be less than
4,375 pounds.

53.2.3 Peak crush resistance. The peak crush
resistance shall not be less than three and one half
times the curb weight of the vehicle or 12,000
pounds, whichever is less.

S4 Test procedures. The following procedures
apply to determining compliance with section S3:
(a) Place side windows in their uppermost posi-
tion and all doors in locked position. Place the sill
of the side of the vehicle opposite to the side

being tested against a rigid unyielding vertical
surface. Fix the vehicle rigidly in position by
means of tiedown attachments located at or for-
ward of the front wheel centerline and at or rear-
ward of the rear wheel centerline.

(b) Prepare a loading device consisting of a
rigid steel cylinder or semi-cylinder 12 inches in
diameter with an edge radius of one-half inch.
The length of the loading device shall be such
that the top surface of the loading device is at
least one-half inch above the bottom edge of the
door window opening but not of a length that will
cause contact with any structure above the bottom
edge of the door window opening during the test.

(1) Its longitudinal axis is vertical;

CENTERLINE OF VEHICLE

12 INCH DIAM

PLAN VIEW

HORIZONTAL LINE
5 INCHES ABOVE THE
LOWEST POINT OF
THE DOOR

1/2 IN. R.

STRUCTURES ABOVE THE
BOTTOM EDGE OF THE DOOR
.WINDOW OPENING

- BOTTOM EDGE
OF DOOR WINDOW
OPENING

MID POINT OF LINE
LOWEST POINT OF THE DOOR

SIDE VIEW
Figure 1 — Loading Device Location and Application to the Door

PART 571; 214-3

(2) Its longitudinal axis is laterally opposite
the midpoint of a horizontal line drawn across
the outer surface of the door 5 inches above the
lowest point of the door;

(3) Its bottom surface is in the same hori-
zontal plane as the horizontal line described in
subdivision (2) of this subparagraph; and

(4) The cylindrical face of the device is in
contact with the outer surface of the door.

(d) Using the loading device, apply a load to
the outer surface of the door in an inboard direc-
tion normal to a vertical plane along the vehicle's
longitudinal centerline. Apply the load continu-
ously such that the loading device travel rate does
not exceed one-half inch per second until the
loading device travels 18 inches. Guide the load-
ing device to prevent it from being rotated or dis-
placed fro
far forward as possible so that the heels rest on the
floorpan.

57.4.3 For a test dummy in either of the rear
outboard passenger positions. The feet of the
test dummy are placed flat on the floorpan and
beneath the front seat as far as possible without
front seat interference. If necessary, the distance
between the knees can be changed in order to
place the feet beneath the seat.

PART 571; 214-9

(Rev. 5/21/92)

S8 Phase-in of dynamic test and performance
requirements.

58.1 Passenger cars manufactured on or
after September 1, 1993 and before September
1, 1994.

S8.1.1 The number of passenger cars complying
with the requirements of 53(c) shall be not less
than 10 percent of —

(a) The average annual production of passenger
cars manufactured on or after September 1,1990,
and before September 1, 1993, by each manufac-
turer; or

(b) The manufacturer's annual production of
passenger cars during the period specified in S8.1.

58.2 Passenger cars manufactured on or
after September 1, 1994 and before September
1, 1995.

S8.2.1 The number of passenger cars complying
with the requirements of S3(c) shall be not less
than 25 percent of —

(a) The average annual production of passenger
cars manufactured on or after September 1, 1991,
and before September 1, 1994, by each manufac-
turer; or

(b) The manufacturer's annual production of
passenger cars during the period specified in S8.2.

58.3 Passenger cars manufactured on or
after September 1, 1995 and before September
1,1996.

S8.3.1 The number of passenger cars complying
with the requirements of S3(c) shall be not less
than 40 percent of—

(a) The average annual production of passenger
cars manufactured on or after September 1, 1992,
and before September 1, 1995, by each manufac-
turer; or

(b) The manufacturer's annual production of
passenger cars during the period specified in S8.3.

58.4 Passenger cars produced by more than
one manufacturer.

S8.4.1 For the purposes of calculating average
annual production of passenger cars for each
manufacturer and the number of passenger cars
manufactured by each manufacturer under S8.1,

S8.2, and S8.3, a passenger car produced by more
than one manufacturer shall be attributed to a sin-
gle manufacturer as follows, subject to S8.4.2 — ^

(a) A passenger car which is imported shall be
attributed to the importer.

(b) A passenger car manufactured in the United
States by more than one manufacturer, one of
which also markets the vehicles, shall be attrib-
uted to the manufacturer which markets the
vehicle.

S8.4.2 A passenger car produced by more than
one manufacturer shall be attributed to any one of
the vehicle's manufacturers specified by an
express written contract, reported to the National
Highway Traffic Safety Administration under 49
CFR Part 586, between the manufacturer so speci-
fied and the manufacturer to which the vehicle
would otherwise be attributed under S8.4.1.

[S9 Phase-in of side door strenqth require-
ments for multipurpose passenqer vehicles,
trucks and buses.

[S9.1 Multipurpose passenqer vehicles, trucks

and buses manufactured on or after Septem- d^

ber 1, 1993 and before September 1, 1994. •

[S9.1.1 The combined number of multipurpose
passenger vehicles, trucks and buses with a
GVWR of 10,000 pounds or less complying with
the requirements of S3(a)(3) shall not be less than
90 percent of —

[(a) The average annual production of multi-
purpose passenger vehicles, trucks and buses with
a GVWR of 10,000 pounds or less manufactured
on or after September 1, 1990 and before Septem-
ber 1, 1993 by each manufacturer; or

[(b) The manufacturer's annual production of
multipurpose passenger vehicles, trucks and buses
with a GVWR of 10,000 pounds or less during
the period specified in S9.1.

[S9.1 .2 Walk-in vans, vehicles which do not have
any side doors that can be used for occupant
egress, vehicles which exclusively have doors of
the types specified in S3(e), and vehicles specified
in S9.2.3 may be excluded from all calculations of
comphance with S9. 1 . 1 . ^

(Rev. 7/13/92)

PART 571; 214-10

[S9.2 Multipurpose passenger vehicles,
trucks and buses produced by more than one
manufacturer.

[S9.2.1 For the purposes of calculating average
annual production of multipurpose passenger
vehicles, trucks and buses with a GVWR of
10,000 pounds or less for each manufacturer and
the number of multipurpose passenger vehicles,
trucks and buses with a GVWR of 10,000 pounds
or less manufactured by each manufacturer under
S9.1,l, a vehicle produced by more than one
manufacturer shall be attributed to a single manu-
facturer as follows, subject to S9.2.2 —

[(a) A vehicle which is imported shall be
attributed to the importer.

[(b) A vehicle manufactured in the United
States by more than one manufacturer, one of
which also markets the vehicle, shall be attributed
to the manufacturer which markets the vehicle.

[S9.2.2 A vehicle produced by more than one
manufacturer shall be attributed to any one of the
vehicle's manufacturers specified by an express
written contract, reported to the National Highway
Traffic Safety Administration under 49 CFR Part
586, between the manufacturer so specified and
the manufacturer to which the vehicle would
otherwise be attributed under S9.2.1.

[S9.2.3 Each multipurpose passenger vehicle,
truck and bus with a GVWR of 10,000 pounds or
less that is manufactured in two or more stages or
that is altered (within the meaning of §567.7 of
this Chapter) after having previously been cer-
tified in accordance with Part 567 of this Chapter
is not subject to the requirements of S3(a)(3). (57
F.R. 30917— July 13, 1992. Effective: September 1,
1993.)]

July 13, 1992
57 F.R. 30917

PART 571; 214-11

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE

SAFETY STANDARD NO. 217

Bus Window Retention and Release

(Docket No. 88-21 ; Notice 3)
RIN 2127-AC88

ACTION: Final rule.

SUMMARY: This rule amends Federal Motor
Vehicle Safety Standard No. 217, Bus Window
Retention and Release, by revising the minimum
requirements for school bus emergency exits and
improving access to school bus emergency doors.
Instead of requiring all school buses to have the
same number of exits, as the standard currently
does, this rule sets requirements for minimum
emergency exit space based upon the seating
capacity of each bus. Thus, larger school buses are
required to have an increased number of exits.
This rule also requires school buses to provide
improved access to side emergency doors. In addi-
tion, this rule includes requirements to improve
the visibility of school bus emergency exits. This
rule is intended to facilitate the exiting of occu-
pants from a bus after an accident and thus
improve the likelihood of their survival.

EFFECTIVE DATE: This rule is effective May 2,
1994.

SUPPLEMENTARY INFORMATION:

Background
School buses are an extremely safe means of
transportation. The most recent available informa-
tion (i.e., data for the 1989-90 school year)
indicates that approximately 370,000 public
school buses traveled over 3.5 billion miles to
transport over 22 million children to public
schools. In its May 1989 report, "Improving
School Bus Safety," the National Academy of
Sciences estimated that another 20,000 school
buses traveled 0.5 billion miles to transport 3 mil-
lion school children to private schools. The safety
record of school buses in protecting school bus
occupants while traveling these billions of miles
is impressive. On a vehicle-mile basis, school
buses are about four times safer than passenger

cars. Despite this outstanding safety record,
school bus crashes do occur and occasionally seri-
ous injuries and fatalities result.

An important factor in minimizing post-crash
injuries and deaths on buses is the speed and ease
with which occupants can evacuate the vehicle in
an emergency. When Standard No. 217, Bus Win-
dow Retention and Release, originally became
effective on September 1, 1973, it required that
buses other than school buses have exits whose
combined area, in square inches, equaled or
exceeded 67 times the number of designated seat-
ing positions. The type of exit used to comply
with this requirement was left to the choice of the
manufacturer, although the agency assumed that
most manufacturers would meet the standard pri-
marily by installing push-out side windows.

School buses were excluded from this require-
ment for the reasons explained in the notice of
proposed rulemaking [NPRM]:

In view of discipline problems associated with
mandatory quick-release and exit devices throughout a
school bus which may interfere with the school bus
driver's task, and the added risk of children falling
from moving school buses, push-out windows for
school buses would remain optional. 35 PR 13025;
August 15, 1970.

The Standard did require that when a school
bus was voluntarily equipped with push-out win-
dows or with other emergency exits, those exits
must confomi to the same requirements specified
in the Standard for exits in buses other than
school buses.

In response to the Motor Vehicle and School-
bus Safety Amendments of 1974 (Pub. L. 93-
492), Standard No. 217 was amended to include
emergency exit requirements for school buses.
Instead of simply specifying that the total com-
bined area, in square inches, of all the exits had
to equal or exceed 67 times the number of des-

PART 571; S 217— PRE-23

ignated seating positions, and leaving the choice
of exit type to the manufacturer, the agency
required (and continues to require) that all new
school buses have either (1) one rear emergency
door, or (2) "one emergency door on the
vehicle's left side that is in the rear half of the
bus passenger compartment and is hinged on its
forward side, and one push-out rear window."
Like all of the agency's safety standards for
motor vehicles. Standard No. 217 is a minimum
safety standard, in this instance specifying the
fewest permissible number of emergency exits for
a school bus.

In May 1988, 27 persons died of smoke inhala-
tion in the fire resulting from the high-speed
crash of a pick-up truck (driven by a drunk
driver) and a used school bus in Carrollton, Ken-
tucky. Several factors were involved in this tragic
event, which represented the first fire-related
occupant deaths on a school bus-type vehicle
since NHTSA began compiling statistics on traffic
fatalities in 1975. Some observers suggested that
more occupants might have survived the fire if
the bus had been equipped with additional (or
more accessible) emergency exits. That bus had
been manufactured in March 1977, shortly before
the new NHTSA school bus safety standards took
effect, including upgraded requirements for Stand-
ard No. 217. This crash focused considerable pub-
lic interest on several school bus safety issues,
including emergency exits, as well as on the
continuing problem of drunk driving. More
recently, attention was again focused on school
bus exits by the September 1989 crash in Alton,
Texas, in which a tractor semi-trailer struck a
school bus, which then rolled into a water-filled
gravel pit. Twenty-one students drowned as a
result of this crash.

Following the Carrollton crash, NHTSA under-
took a comprehensive review of its vehicle stand-
ards and other programs for school bus safety,
and published a summary report in November
1988. That report noted the excellent overall
safety record of school buses, but also highlighted
areas where further improvements might be made.
The National Academy of Sciences [NAS]
reached similar conclusions in its report on school
bus safety, issued in May 1989.

In November 1988, NHTSA issued an
advanced notice of proposed rulemaking
[ANPRM] on whether to upgrade Standard No.
217 to specifically enhance the requirements for

school bus emergency exits (53 FR 44627;
November 4, 1988). The notice explored whether
rulemaking to require additional emergency exits ^
was warranted. It posed a series of 24 questions W
divided into six categories: safety need, require-
ments for additional exits, the effect of additional
exits on other aspects of safety, cost of additional
exits, encouraging the correct use of emergency
exits, and other factors incident to requiring more
emergency exits. NHTSA received 49 comments
in response to the ANPRM. The commenters
included Federal, State and local government
agencies, local school districts, pupil transpor-
tation services and associations, bus and equip-
ment manufacturers, and the general public.

After considering the responses to the Novem-
ber 1988 ANPRM, NHTSA issued an NPRM
proposing to amend Standard No. 217 to require
that the minimum emergency exit space on school
buses be based upon the seating capacity of the
school bus so that emergency exit capability
would be proportional to the maximum occupant
capacity of the school bus and the school bus
emergency exits requirements would be com-
parable to the requirements for non-school buses
(56 FR 11153; March 15, 1991). The NPRM pro-
posed two options for how the additional emer- ^
gency exit space required by the proposed for-
mula would be provided. That notice described
the options as follows:

Option A would provide that all additional exits
required under the proposal be side exit doors. * * *
Option B would require likewise, that where one addi-
tional exit is required, it must be a side exit emergency
door, but that where the additional exit space required
exceeds the area created by that door (1080 square
inches), the next 540 square inches of exit space must
be provided by a roof exit, and the next 540 square
inches provided by a second roof exit. The maximum
credit for one roof exit would be 540 square inches,
regardless of its actual size. If additional exit space
beyond that provided by the side exit door and two
roof exits is required (i.e., more than 2160 square
inches of additional exit space is required), the pro-
posal would require a second additional side exit emer-
gency door. * * *

The location for emergency exits under each
option was specified. Additionally, the NPRM
proposed to require that: Roof exits have a for-
ward hinge and comply with the emergency .
release requirements of S5.3; emergency exit «
doors have a device to cause them to remain open

PART 571: S 217— PRE-24

once they have been opened past a certain point;
seats adjacent to side emergency exit doors have

)y\] flip-up seat bottoms; and the outline of school bus
-^ emergency exits be marked with retroreflective
tape on both the interior and exterior sides of the
bus.

NHTSA received 29 comments in response to
this NPRM. All of these comments were consid-
ered while formulating this final rule, and the
most significant comments are addressed below.

The most significant difference between the
final rule and the NPRM concerns the means by
which the additional emergency exit space will be
provided. The requirement in the final rule is
most similar to Option B in the NPRM, in that
the first additional exit must be a side door and
the second additional exit must be a roof exit.
However, the final rule allows manufacturers to
choose between side door exits, roof exits, and
window exits in providing any additional required
exit space. Additionally, the exact location of
additional emergency exits is no longer specified.
The final rule also differs from the NPRM in the
types of markings that must be provided for
emergency exits.

r 1 . Capacity-based Emergency Exit Requirements

The NPRM proposed to require that school
buses provide minimum emergency exit spaces
equal, in square inches, to 67 times the number
of seating positions. Several commenters, includ-
ing the National Transportation Safety Board
[NTSB], the National School Transportation
Association [NSTA], and several states, specifi-
cally voiced support for capacity-based emer-
gency exit requirements for school buses. How-
ever, the Minnesota Department of Education
[Minnesota] stated its belief that "the rule as pro-
posed goes too far in trying to prevent or mini-
mize damages from events that are extremely
rare. Greater safety can be provided by targeting
funds to other areas, such as driver training." The
agency acknowledges the extremely safe record of
school buses, but believes that it is important to
safeguard against catastrophic-type crashes by
ensuring that the occupants of school buses have
adequate amounts of emergency exit space
located in several locations throughout the bus.
This is particularly important as more higher-
capacity school buses are being manufactured.
Based upon information in the annual statistical
issue of "School Bus Fleet Magazine." in

comparing 1991 to 1987, the number of Type C
buses (24-76 passengers) sold decreased by
approximately 8,000, while the number of Type D
buses (78 passengers and over) sold increased by
approximately 5,600.

Additionally, while the agency recognizes the
importance of school bus driver training pro-
grams, it notes the importance of school bus driv-
ers having the best equipment available to them
in order to do their job. Even the best drivers can-
not do their best with inferior equipment. Con-
versely, the best equipment in the hands of
untrained drivers does not guarantee the safe
operation of a school bus.

The Oregon Department of Education [Oregon]
agreed that a capacity-based method for determin-
ing the amount of emergency exit area should be
adopted, but stated that using the same formula
leaves a discrepancy between school buses and
non-school buses. Oregon believed that school
buses establish the maximum seating capacity
based on a 13 inch wide seat space per individual,
while non-school buses use a 15-18 inch space
for a seating position. Oregon suggested this dif-
ference be taken into consideration by either
developing "a more compatible seating position
definition * * * or by utilizing a reduced square
inch criteria * * * for the determination of num-
ber of required exits."

There is no specific mention of a 13 inch seat-
ing width in any safety standard. Oregon appar-
ently based the 13 inch figure on the requirements
of Standard No. 222, School Bus Passenger Seat-
ing and Crash Protection. Section S4.1 of Stand-
ard No. 222 calculates the maximum number of
seating positions on a school bus bench seat by
dividing the seat width by 15, and rounding the
result to the nearest whole number. Using the
industry "standard" seat width of 39 inches, the
calculated maximum number of seating positions
is 3 (39/15 = 2.6, rounded to 3). If one then
divides the actual seat width (39 inches) by the
calculated maximum number of seating positions
(3), a 13 inch seating width can be inferred. This
requirement is intended to ensure that the seat
will be constructed to provide adequate crash
protection when occupied by the maximum num-
ber of passengers. Many of those passengers are
likely to be younger and smaller than the typical
passengers who ride in non-school buses.

It appears that Oregon's concerns stem from
the resulting number and cost of additional emer-

PART571: S 217— PRE-25

gency exits for school buses. If the agency
adopted Oregon's suggestions for calculating the
total amount of emergency exit space, a smaller
number of exits would result. The agency believes
that it is appropriate to base the emergency exit
requirements for school buses on the maximum
potential capacity of the bus rather than a lesser
number, just as it is appropriate to base the crash
protection requirements on the maximum potential
capacity of each seat. School buses are often
operated at or near capacity. Further, it is impor-
tant to ensure that adequate emergency exit space
is available no matter whether the school bus is
filled with kindergarten-size students or high
school-size students. Therefore, the final rule pro-
vides that "(t)he area in square inches of unob-
structed openings for emergency exit shall collec-
tively amount to at least 67 times the number of
designated seating positions in the bus."

2. Option A (Emergency Exit Doors} or Option B
(Doors and Roof Hatches)

As explained previously, the NPRM proposed
two options for adding emergency exits to school
buses. Option A would have required that only
side emergency exit doors be installed to meet the
proposed additional emergency exit requirements.
Option B would have required that a combination
of side emergency exit doors and roof hatches be
installed to meet the additional emergency exit
requirements.

Several commenters expressed support for
Option A. However, many of these also expressed
support for roof hatches. For example, Oregon
stated that Option A "appears to provide the most
equal distribution of emergency exits," but "rec-
ommended that Option A be amended to include
at least 1 roof exit."

Most commenters expressed support for Option
B or a variation of it adopted by the 11th
National Conference on School Transportation.
But many of these commenters also expressed
support for even greater usage of roof hatches
than Option B would have required. For example,
the Arizona Department of Transportation
[Arizona-DOT] noted that buses with a capacity
of "48 passengers or less should be required to
have at least one roof hatch." The Iowa Depart-
ment of Education [Iowa] stated that Option B
should be adopted, but that it should be "amend-
ed to require at least one emergency roof escape
for most, if not all school bus applications."

Only the Colorado Department of Education
[Colorado] expressed total opposition to roof
hatches, and therefore to Option B. It expressed A
technical concerns with roof hatches, particularly
the "draft effect" of a roof hatch in a fire, as
well as the potential dangers of dripping plastic
from the hatch in a fire. Colorado also questioned
whether or not the installation of a roof hatch
would compromise a bus's ability to withstand
rollover crashes. (A discussion of these concerns
appears under Section 5, Roof Exits — Design and
Size.) Further, it noted that in 5 years, only .7
percent of the Colorado school bus crashes have
involved a bus rolling over on its side. This
means that "(s)tudents would not have had the
need to use roof hatches as an exit 99.3% of the
time."

A number of commenters expressed strong
convictions on the efficacy of various types of
emergency exits. The NSTA supported "the use
of push-out windows, side door or roof hatches to
meet the emergency exit space requirements. The
type of exit used to comply with the requirement
should be the choice of the purchaser and manu-
facturer." The Montana Office of Public Instruc-
tion [Montana] believed that the states should ^
have "some choice in choosing emergency escape ^
windows, doors or roof hatches."

The Eagle County Colorado School District
[Eagle County] noted that while it supported the
need for more emergency exits, it believed
"(d)ifferences among school districts such as in
terrain and types of pupils transported must
necessitate local decisions on the number, type
and location of emergency exits." The Salem-
Keizer Oregon Public Schools [Salem-Keizer]
supported the agency's proposals for establishing
emergency exit requirements based on school bus
capacity, however, it believed push-out windows
serve a useful purpose. It liked the "approach for
providing a variety of exits for meeting a variety
of uncertainties," and asked that the agency not
"rule against push-out windows!"

Based on the comments, the agency believes
that there are benefits to providing a variety of
emergency exit types distributed throughout the
bus as a precaution against a wide variety of
potential emergency exit situations. Roof hatches
would be a very beneficial type of emergency exit
when the bus is on its side; however, it would be ^

difficult for many students to use roof exits in
other situations. It is also possible to envision a

PART 571; S 217— PRE-26

situation in which a bus comes to rest in a posi-

^^ tion where one or more emergency exits on a side

\j would be too close to a tree, pole, guardrail,

' bridge abutment or other vehicle to allow it to

open, or to open completely. In such an instance,

it would be useful to have emergency exits

distributed in other areas of the bus. Accordingly,

the agency has decided that school buses should

have a variety of exit types distributed throughout

the passenger compartment.

The agency has determined that after calculat-
ing the total amount of additional emergency exit
area [AEEA] needed for a school bus, using the
formula proposed in the NPRM, the first addi-
tional amount of emergency exit area must be met
with a side emergency exit door; the second addi-
tional amount of emergency exit area must be met
with an emergency roof exit. Unlike Option B in
the NPRM, however, the final rule provides that
any remaining emergency exit area can be met
with either a side emergency exit door, a roof
emergency exit, or an emergency exit window.
The specification of a side emergency exit door
as the first priority is consistent with the NPRM
which noted that, "if a bus is required to have
^ only one additional exit * * *, that exit should be
fj a side exit emergency door." Allowing AEEA to
be met with an emergency exit window in some
circumstances, however, differs from the agency's
position in the NPRM.

In the NPRM, the agency stated three reasons
why it did not want to encourage the use of push-
out windows. First, push-out "windows are usu-
ally higher off the ground and smaller in size than
exit doors, which make them difficult for school
age occupants to use." Second, "push-out win-
dows are almost never used as a means of escape
during school bus evacuation drills." Third,
"push-out windows are likely targets of tamper-
ing." (56 FR 11153, 11155)

Nearly all commenters responding to the
NPRM expressed an opinion concerning push-out
windows. Most of these comments were based on
the commenters' own successful experiences with
such devices. For example, the Lake Oswego
Oregon School District [Lake Oswego] stated that
it has used push-out windows for nearly twenty
years and that push-out windows "are at no
greater risk of 'tampering' than any other emer-
I gency exit. (T)hey certainly are of less of a threat

of students falling if they 'play' with them, than
a side door." Minnesota believed that "pushout

windows will maintain structural integrity of the
vehicle better than numerous side emergency
doors." Summing up the sentiment of com-
menters like these. Blue Bird stated that "(i)n the
final analysis. State governments have the ulti-
mate responsibility for selecting the features that
they believe will best protect the safety of the
passengers they transport."

Given the almost uniformly negative response
to the agency's position on push-out windows, the
agency reexamined its position. First, given the
experiences with tampering reported by the com-
menters and that students may be sitting near side
emergency doors, the agency no longer believes
that push-out windows are a more likely target for
tampering than an emergency exit door. While the
agency continues to believe that push-out win-
dows are less likely to be used in an emergency,
the agency does not have any accident data to
suggest that these windows are unsafe. Given that
a large number of school districts currently
require push-out windows in addition to the
requirements of Standard No. 217 and have not
reported any problems with them, the agency has
been persuaded to allow push-out windows to be
counted towards the AEEA requirements for some
buses. Since the first amount of AEEA must be
met with a side emergency door, the second
amount of AEEA with a roof exit, only large-
capacity buses, typically those with a seating
capacity exceeding 70, will be able to take advan-
tage of this option.

NHTSA suggests that States and school dis-
tricts consider the agency's concerns about the
use of push-out windows when choosing between
side doors, roof exits and push-out windows for
larger school buses. For States and school districts
that allow or require push-out windows in school
buses, the agency suggests further that training
programs include instruction in the use of these
windows.

3. Emergency Exit Doors
While there were a number of comments to the
docket in support of requiring only emergency
exit doors and roof hatches, some commenters
expressed concerns over the structural impact of
additional side emergency exit doors. Thomas
Built Buses [Thomas Built] stated that in terms of
intrusion, it has been shown "that the structural
integrity of the area around the side emergency
door can be just as sound as an area along the

PART 571; S 217— PRE-27

side of the bus that does not have a side emer-
gency door." However, on the subject of fatigue
strength. Thomas Built has "seen evidence that
the bus's fatigue strength has been compromised
when a side door is installed on various types and
brands of buses. This evidence shows up after
years of use and is in the form of cracked struc-
tural members and panels." The placement of the
door, depending on the "body length, front
engine, rear engine, and operating conditions,"
can have "detrimental effects on structural
fatigue." "Problems can show up early (1-2
years) or later (3-10 years)."

The agency does not believe the fatigue
strength concerns expressed by Thomas Built are
unique to side emergency exit doors. In-use
fatigue problems can result from a variety of
operational factors, including climate and roadway
factors, that can affect many areas in all types of
buses.

With respect to these "fatigue strength" con-
cerns, the agency notes that: (1) rear-engine
school buses have been equipped with a left side
emergency exit door since 1977; (2) several
States (e.g., California, New York, and Washing-
ton) already require additional side emergency
doors in their school buses: (3) a large number of
school buses are equipped with wheelchair lifts
which essentially represent an oversized side
emergency exit door; and (4) these buses do not
appear to be suffering from large numbers of
design structural integrity problems or fatigue
strength life cycle problems. For these reasons,
the agency believes requiring a single side emer-
gency exit door in school buses currendy
equipped with a rear emergency door or an addi-
tional side emergency exit door on a school bus
with a left side emergency exit door will not
compromise the structural or life cycle character-
istics of school buses.

4. Window Size
Three commenters directly addressed the size
of the standard (non-emergency exit) windows on
school buses. These comments attempted to sepa-
rate emergency evacuation situations into two
types. The first were the routine evacuations
where time is not necessarily critical and the serv-
ice entry door and other floor level emergency
exits would be utilized. The second were cata-
strophic-type crashes where the school bus occu-
pants have to evacuate the vehicle as fast as pos-

sible. In its comments to the NPRM, the Califor-
nia Department of Education [California] noted
that "NHTSA could have also enhanced pas- ^
senger safety by requiring the passenger window
opening to be at least 12" by 22" in area." (Cur-
rently, most school buses are built with split-sash
windows which drop to provide an opening of 9"
high X 22" wide.) California stated that while
each window should not be a designated emer-
gency exit, "a larger window opening would pro-
vide passenger(s) in each seat location direct
egress from the bus in a catastrophic accident
similar to the accidents in Carrollton, Kentucky
and Alton, Texas. Many lives may have been
saved if only the passenger windows would have
provided a large enough opening to permit the
passengers to escape." A similar comment was
submitted by Washington.

TAM-USA stated that one of the conclusions
from the NTSB's investigation of the Alton,
Texas, school bus crash was that "larger vertical
openings of the side windows would have
improved the occupants' ability to escape."
TAM-USA further commented that establishing
minimum window size openings as a:

remedy for total and immediate evacuation from cata- ^
strophic accidents * * * serves a number of purposes.
First, it recognizes that such accidents are unique, and
normal rules of, and training for, evacuation in such
accidents do not apply. Second, it recognizes that no
single set of measures can address every possible
accident scenario. Third, addressing the problem in this
way permits NHTSA to focus the rest of its thinking
and logic on the vast majority of accidents which are
not catastrophic, and to which passenger training and
coordination with safety features can produce optimum
and measurable results.

Finally, TAM-USA stated that in the Alton crash
"push-out windows would not have worked, since
each window would have had several hundred
pounds of water pressure on it." Accordingly, it
believed "simple sliding passenger windows, with
large window openings, are far less expensive,
could be applied to the entire bus, and do not
possess most of the problems associated with
push-out windows."

Along the same vein. Blue Bird stated that it
has several side emergency exit designs under
development, including a vertical slide open win-
dow and side exit hatch or shorter emergency exit L
door. In order to encourage, and certamly not to
prohibit, further development and use of these

PART 571: S 217— PRE-28

types of exits, Blue Bird believed language should
be included in the school bus requirements that
h would provide for emergency exit side windows
with a maximum amount of credit of 536 square
inches.

While the agency understands the comments
concerning the wisdom of larger standard win-
dows in school buses to facilitate evacuation dur-
ing catastrophic situations, it is concerned about
the potential negative aspects of larger windows.
Specifically, the agency is concerned about the
greater potential danger to a child who sticks a
hand, arm, or head out of the window while the
bus is in motion. It is clearly easier for a child
to hang out of a 12 inch x 22 inch window than
a 9 inch x 22 inch window. The agency recog-
nizes that some state and local school districts are
currently using school buses with larger windows,
without large numbers of incidents where children
are hurt because of them. Taken all together, the
infomiation available to the agency appears to
provide some evidence that the potential benefits
may be greater than the potential risks.

As was stated in Washington's comments,
states do not want "every school bus window to
\ be considered a designated exit." If windows
were so regarded, each of them would be required
to meet the Standard No. 217 requirements for
emergency exits, including audible warnings,
locking devices, labeling, etc. Also, as was stated
in the TAM-USA comments, the importance of
evacuation routes at every seat is relevant only in
catastrophic crashes. Since the overwhelming
majority of school bus evacuations do not occur
in connection with catastrophic crashes, the
agency believes there is a need for designated
emergency exits, which can be accomplished with
doors, hatches, and/or push-out windows. How-
ever, the agency does not believe there is suffi-
cient justification to support a Federal mandate
for non-designated emergency exits, which could
be obtained from larger school bus window open-
ings throughout the bus.

Accordingly, while the agency supports the
concept of each student having a personal escape
route, whether it be through a designated or non-
designated emergency exit, it does not believe
there are sufficient grounds for establishing mini-
mum window opening sizes for non-designated
emergency exits. However, the agency notes that
the use of larger windows is permissible for those
states that wish to have them.

5. Roof Exits— Design and Size
Support for roof exits came from a wide range
of commenters. As noted earlier, some com-
menters (Iowa and Arizona-DOT) went so far as
to state that all school buses should be equipped
with at least one roof hatch. Only Colorado
expressed concern about roof exits, particularly in
a fire situation where a roof hatch could create a
"chimney effect" and worsen the fire. While
Colorado is correct that an open roof hatch would
create a chimney for smoke and heat to escape,
such a result is desirable. Heat and smoke are at
least as much of a threat to bus occupants as the
fire itself. While the open roof hatch would help
vent heat and smoke out of the bus, it can also
result in more oxygen being drawn into the bus.
While this additional oxygen will provide addi-
tional "fuel" for the fire, it will also provide
additional oxygen for anyone in the bus. On bal-
ance, the agency believes the positive aspects of
open roof hatches in a bus fire outweigh any
potential negative aspects.

A number of commenters discussed their
beliefs that recessed roof hatch requirements, as
mentioned in the NPRM, would be more suscep-
tible to binding in a crash and would require
some type of internal draining system that would
add cost to the bus. Thomas Built stated that
"(r)ecessing the hatch would create greater prob-
lems than the 'predicted' problem attempting to
be solved." It cites potential jamming from body
twist, as well as water drainage (and rust) prob-
lems. Blue Bird stated its belief that current roof
hatch designs are safe and added that it does not
support recessed designs because they are "more
likely to be jammed shut in an accident." Two
roof hatch manufacturers, Transpec and Salem
Vent International [Salem Vent], also agreed that
recessed vents would be more susceptible to bind-
ing in a crash, and believed that the current over-
lay roof hatch designs are the best. Based on
these comments, the agency does not believe that
overlay roof hatches are a safety problem or that
it is necessary to require recessed roof exits.

A number of commenters addressed the issue
of roof exit size. The preamble to the NPRM
stated that, "The maximum credit for one roof
exit would be 540 square inches, regardless of its
actual size." The proposed regulatory language
stated that, "The roof exit shall provide an open-
ing with a minimum clearance of 16 inches and
an area of at least 540 square inches." Only

PART 571: S 217— PRE-29

Thomas Built makes a roof vent that meets the
540 square inch requirement proposed in the
regulatory text. There are no other known manu-
facturers of a roof hatch that large. Transpect
stated that they believe the proposed size require-
ments "will obsolete virtually every roof exit
design currently available; and force bus body
manufacturers and equipment suppliers to spend
potentially millions of dollars in re-designing and
re-tooling." It suggested a minimum size of 20"
X 20", which is "about 50% larger than the cur-
rent minimum size" and will allow passage of the
13" X 20" ellipsoid currently required for push-out
windows under S5. 2.2(b) of Standard No. 217.
Other commenters stated that additional leadtime
would be needed while existing roof exits were
redesigned to meet the minimum area require-
ments.

After reviewing the comments to the docket on
this topic, the agency has decided to delete the
requirement that the roof hatch have an area of at
least 540 square inches. The agency was not
aware that current roof exit designs did not meet
the proposed requirements. However, the agency
believes that a minimum size must be specified
for roof hatches. Therefore, consistent with the
NPRM. each open roof hatch must provide an
unobstructed space of not less than 16 inches by
16 inches. As with all other openings, there is no
limit on the maximum size of the opening. The
regulatory language has been revised accordingly.

The NPRM also proposed that roof exits be
operable from the outside to assist rescue person-
nel in being able to open a roof hatch on an over-
turned school bus in an emergency situation.
Since no commenters objected to this require-
ment, it is included in the final regulatory lan-
guage.

6. Location of Emergency Exits
The NPRM proposed amending existing
S5.2.3.1, governing minimum emergency exit
locations, to specify the location of the additional
exits required by Options A and B. The NPRM
stated, "(t)he agency is concerned that the
required exits maximize emergency egress while
not compromising the structural integrity of the
vehicle." The NPRM then proposed specific loca-
tions for the additional exits under both Options
A and B.

All of the comments concerning the location of
any type of emergency exit supported the concept

of an even distribution of the exits around the
bus. However, the locations proposed in the
NPRM were not always deemed possible or prac- ^
ticable. For example, Thomas Built stated that the
left side emergency door on rear engine buses
"cannot be placed at the extreme rear section
* * * because of the interference with the engine
compartment/davenport seat." Additionally, the
company said that the left and right side emer-
gency exit doors should not be "within the same
post and roof bow panel space."

Blue Bird stated that because of design restric-
tions related to such items as wheelhousings, fuel
filler necks, seat placements, etc., there are a
number of problems in specifying side door loca-
tions. Accordingly, Blue Bird "strongly rec-
ommends that NHTSA conduct further research to
detennine the effects and feasibility of requiring
specific exit locations."

Other commenters endorsed the even distribu-
tion of emergency exits, but believed that states
should have the flexibility of establishing the
location of emergency exits. California believed
"(t)he location of the side exit doors and roof
vent/exits should be optional to each state."

Washington, which has required additional side ^
emergency exit doors on most buses since 1954, ™
supported the concept of specifying the locations
of emergency exits. Its experience indicated that
if the locations of emergency exits are left to the
discretion of the manufacturers, doors could be
installed in a manner that "meets the letter of the
law * * * (but) does not meet the intent of the
requirement."

Transpec commented that when two roof exits
are utilized, "they should be located equidistant
between the mid-point and the front and rear of
the passenger compartment * * * jj^ other words
the forward Va and the rearward Va of the overall
passenger compartment length." This differs from
the proposal of the forward Vi and rearward '/s.
Transpec stated that its alternative would better
minimize the distance any single passenger would
have to travel to reach a roof exit.

Based on the above, the agency has concluded
that there are legitimate technical issues relative
to establishing specific locations for side door
exits in school buses. Differences in chassis and
body designs among manufacturers would neces-
sitate the establishment of standards on a make/ 4
model basis, which could hinder school bus safety
improvements in the future. The agency has con-

PART 571: S 217— PRE-30

eluded that emergency exits should be evenly
distributed throughout the bus, to the extent pos-
sible. For example, if an emergency exit door is
added to a school bus with an existing rear door
emergency exit, the additional door must be
located on the left side of the bus and as close
to the center of the bus as is practicable. If an
emergency exit door is added to a school bus with
an existing left side emergency exit door, the
additional door must be located on the right side
of the bus.

With respect to roof hatches, the agency agrees
with the location specifications suggested by
Transpec because these specifications minimize
the distance from the roof exits to the farthest
school bus seat. Therefore, the agency has con-
cluded that when a single roof hatch is installed
in a school bus, it must be located as near as
practicable to the longitudinal mid-point of the
passenger compartment, and must be installed
such that the centerline of the hatch is on the
longitudinal centerline of the bus. When 2 roof
hatches are utilized, they shall be located as near
as practicable to the points equidistant between
the longitudinal mid-point of the passenger
compartment and the front and the rear of the
I passenger compartment. When multiple roof
hatches are utilized, they may be installed either
on the longitudinal centerline of the bus or offset
from the centerline. For each roof hatch that is
installed in an offset manner, there must be
another roof hatch offset an equal amount to the
other side of the centerline.

If a state chooses to install emergency exit win-
dows in order to satisfy some of the exit space
required by the standard, there must be an even
number of such windows and they must be evenly
distributed between the left and right side of the
bus.

Consistent with giving states the flexibility of
selecting some of the types of emergency exits
used (doors versus hatches versus windows), the
agency has concluded that states are in the best
position to specify the exact locations of emer-
gency exits on school buses. The final rule, there-
fore, establishes general requirements for school
bus emergency exit locations. The agency antici-
pates that the individual states will include more
specific location information in their school bus
specifications and work with the school bus
manufacturers during the construction of their
school buses to establish emergency exit locations

that provide for the safe, organized, and efficient
egress of passengers from all school bus seats.

7. Improved Access to Emergency Exits

The NPRM proposed that if school bus manu-
facturers placed seats adjacent to a side emer-
gency exit door, those seats must have flip-up
bottoms in order to provide a path to the door.
The path would have been somewhat less than 24
inches wide. The location of the path in relation
to sides of the door opening would have been
fixed by a reference to the forward edge of the
door. If this proposal were adopted, manufacturers
not wishing to install flip-up seats would have
had the option of complying by providing an
open aisle to the side door. Under that option, the
aisle would have extended the full width of the
door, a minimum of 24 inches.

The agency considered, but tentatively rejected,
two more costly alternatives. One would have
required the unobstructed passage of a rectangular
parallelepiped (12" x 24" x 45") through each
side door opening a distance of one foot inside
the outside door frame edge. The other would
have required the unobstructed passage of a
rectangular parallelepiped through the door open-
ing all the way to the center of the aisle, thereby
creating a dedicated aisle to the side door. The
path to the door created by the passage of the
parallelepiped would not have been referenced to
either the forward or the rearward edge of the
door. Although the agency tentatively rejected
both of these other options, the agency sought
comment on them to aid in determining what
requirements regarding access should be adopted.

Several states and school districts, two bus
manufacturers, and a national association sup-
ported the proposal to require that seats adjacent
to side emergency exit doors have flip-up seat
bottoms. Oregon, Salem-Keizer, Minnesota, Eagle
County, Thomas Built, TAM-USA, and NSTA
indicated that they preferred providing a flip-up
seat at side emergency exit doors, instead of a
dedicated aisle, primarily because of perceived
capacity loss and resulting additional costs associ-
ated with the latter alternative. Thomas Built
commented that if an aisle were mandated, the
aisle should have a minimum width of 12 inches.

Several states supported dedicated aisles. Mary-
land did not support the use of flip-up seats. It
did not believe a child should be allowed to sit
next to a door, and that a clear aisle leading to

PART 571; S 217— PRE-31

the side door is just as important as a clear aisle
leading to the rear emergency door. Washington
preferred "a clear aisle to the side door.'"
Washington added that it was "aware of the con-
cern for lost seating capacity. However, unless the
bus is already at maximum length, adding a
longer bus body will regain any loss in seating
capacity." While Washington did not have
production data, it suspected that most buses are
not produced at maximum length.

Washington also noted that it has recently
started purchasing flip-up seats and has already
had "two incidences reported where children
have stepped on the seat cushion in a fashion that
allowed the leg to become lodged in between the
seat cushion and the seat back. Once the leg was
stuck, it was a major task to dislodge the leg.
Such an occurrence would have been a disaster if
it happened when the bus was being evacuated
because of an emergency." For this reason,
Washington believed that "(i)f the flip-up seat is
allowed, there needs to be a performance require-
ment that will not allow a child's foot to slip
through the space between the seat cushion and
seat back."

Blue Bird favored requiring a dedicated aisle at
least 12 inches wide. It expressed concern that
"there is limited experience with the use of side
emergency doors and access to these doors."
Only four states require additional side emergency
exit doors, and "two have no seat alignment or
aisle clearance requirements to these doors." Blue
Bird noted that Washington has recently required
seat alignment and a clear aisle, and Kentucky
has recently required a staging area at side emer-
gency doors. Kentucky's requirement appears to
have been adopted in response to the Carrollton,
Kentucky crash. However, "(n)o field experience
with this exit configuration has been accumu-
lated."

Blue Bird stated that the installation of a flip-
up seat at side emergency exit doors instead of a
dedicated aisle does not always eliminate a loss
of capacity. It also noted that it is "not aware of
a flip-up seat design that assures proper function-
ing in all circumstances or that will totally elimi-
nate possible pinching or entrapment potentials."
Blue Bird further stated its concern that in "cer-
tain accident scenarios, occupants could be
thrown off the seat cushion, allowing it to flip up,
and then be rebounded into the upright cushion
which allows the potential for injury." Blue Bird

cautioned "NHTSA to thoroughly evaluate the
proposed requirement for flip-up seats at side
emergency doors before specifying their use." ^

In view of the concerns expressed by com-
menters regarding flip-up seat bottoms, the
agency believes that the preferable manner of
providing access to side emergency exit doors is
through creating a dedicated aisle. However, the
agency recognizes that some states believe flip-up
seats are reasonable alternatives to providing
access to side emergency exit doors. While rec-
ognizing there are some advantages to a dedicated
aisle over a flip-up seat, the agency does not
believe there is sufficient justification or experi-
ence to require dedicated aisles. Accordingly, the
agency has decided to permit either dedicated
aisles or seats with flip-up bottoms. The current
Standard No. 217 language which allows a stand-
ard school bus seat to be next to a side emer-
gency exit door has been eliminated. No special
provisions have been adopted to address the issue
of entrapment since the agency lacks sufficient
information to specify performance requirements
for flip-up seats.

The NPRM also requested comment on
whether the agency should allow a tolerance in £

the relationship of a seat back to the forward edge •

of a side emergency door opening. Thomas Built
and Blue Bird suggested that the proposed lan-
guage regulating the location of a seat back in
relation to the forward edge of the side emer-
gency door could be misinterpreted. Thomas Built
suggested that the S.5.4.2.1(b) language be: "A
vertical transverse plane tangent to the reamnost
point of a seat back shall pass through any points
between 0.5 inches forward of the forward edge
of the door opening and 0.5 inches rearward of
the edge." Blue Bird also suggested rewording of
this section to say that: "the seat back shall be
positioned such that the vertical transverse plane
passes anywhere between points .5 inches forward
or rearward of the door opening." Washington
also agreed that some flexibility in seat back loca-
tion relative to the side door must be allowed and
suggested a "tolerance of one-half of the manu-
facturers seat back thickness."

After reviewing the proposal and the tentatively
rejected alternatives, as well as the public com-
ments, the agency has determined that a provision
requiring that there be a seat back aligned with 4

the forward edge of each side emergency exit
door would be unnecessarily design restrictive.

PART 571: S 217— PRE-32

even if the agency were to provide a tolerance of
0.5 inches. Since the requirement has the effect of
requiring that a seat be installed immediately for-
ward of a side door opening, it could have
undesirable consequences. For example, a manu-
facturer would be prohibited from placing a
wheelchair securement location in that area, even
though the areas near a side door might be the
most logical area if a wheelchair lift were
installed in that door.

However, the agency has determined that the
location of the path to the door should be ref-
erenced to the real edge of the door to ensure
access to the door release mechanism. Because
side emergency exit doors are required to be
hinged on their forward edge, the release mecha-
nisms are located near the rearward edge of the
door. Therefore, the agency has decided to require
an aisle at least 12 inches wide, referenced to the
rear edge of the emergency exit door. In addition,
no seat or restraining barrier will be allowed to
extend rearward of the forwardmost portion of the
latch mechanism when it is in the latched posi-
tion. Some latch mechanisms include a long lever
that extends well forward of the 12 inch clear
aisle required by this rule. A flip-up seat is
allowed in the aisle area adjacent to a side emer-
gency exit door so long as no portion of the seat
bottom is within this aisle area when the seat bot-
tom is in the up position.

8. Three-Point Door Latch
The NPRM requested comment on the likeli-
hood of side door ejections because of additional
side emergency exit doors on school buses.
Additionally, the agency requested comment on
whether additional or improved door exit mecha-
nisms (e.g., a 3-point latching mechanism with
latch points at the top, bottom, and side of the
door) would reduce the risk of ejection.

Several state and local school districts sup-
ported the concept of providing multiple latches
on side doors. Washington, for example, voiced
its support by noting that "(a)ny time there are
multiple latches to fail, the probability of failure
is reduced." Washington and Eagle County
believed that 3-point latches should be used on
rear emergency exit doors as well. Oregon sup-
ported a 3-point latching mechanism, provided it
is "based on test data and the vehicles ability to
meet overall construction standards."

Blue Bird and Thomas Built stated that a side
emergency exit door retention test would be more
appropriate than requiring a 3-point latching
mechanism. Thomas Built noted that passengers
would not be ejected through current side emer-
gency exit doors because of inadequate latching
mechanisms. It stated that "(p)assengers inside
the bus, impacting the door, would not exert
enough force to cause the latch to fail." Thomas
Built believed that "(a) detrimental effect from
the three-point latch is possible jamming" in a
crash. Blue Bird also asserted that "a 3-point
latch mechanism could result in increased
susceptibility to jamming in an accident."

No commenters provided any information to
suggest that side emergency exit doors on school
buses are currently at potential risk of opening in
a crash. The agency is aware that the July 1991
crash of a school bus in Palm Springs, California,
in which the school bus body separated from the
bus chassis and was severely twisted during the
high-speed crash into a series of large boulders,
resulted in the opening of the left side emergency
exit door. The National Transportation Safety
Board has not completed its investigation of that
accident to determine if there were any pas-
sengers injured or killed because of the door
opening during the crash. The structural damage
to the bus body was so severe that it is hard to
imagine that multiple door latches would have
kept the door closed. The door appears to have
opened due to severe damage to the bus body, not
because a passenger was thrown against the door.

After considering the comments of school dis-
tricts and the bus manufacturers, the agency has
concluded that, if a side emergency exit door
retention problem existed, it would be more
appropriate to develop a door retention test, rather
than specifying a specific type of latching mecha-
nism, e.g., a 3-point latch. Even with the recent
crash in Palm Springs, California, the agency
does not believe there is a safety problem with
side emergency exit doors opening due to the
force of passengers being thrown against them.
Additionally, as with emergency roof exits, the
agency is concerned about establishing require-
ments that could increase the potential for jam-
ming shut in a crash, as was suggested by Blue
Bird and Thomas Built. Accordingly, the final
rule does not include requirements for a 3-point
latching mechanism for side emergency exit
doors.

PART 571: S 217— PRE-33

9. Positive Door Opening Device
The NPRM discussed the agency's beUef that
an exit should not only be reachable, but also not
shut once it has been opened, regardless of the
orientation of the bus after a crash. The agency's
concern was directed specifically to emergency
exit doors. Accordingly, the NPRM proposed that
each emergency exit door "be equipped with a
device capable of bearing the weight of the door
and keeping the door from closing past the point
that is perpendicular to the side or rear of the bus
once the door is opened to that point."

The NTSB expressed its support for a device
that would hold an emergency exit door open "to
accommodate passenger egress, particularly in a
rollover situation." This was one of the rec-
ommendations that was included in the NTSB's
report on the September 1989 Alton, Texas,
school bus crash. Two bus manufacturers and four
states also expressed their support for such a
device. Thomas Built and Washington also noted
that such devices were included in the require-
ments of the 11th National Conference on School
Transportation. Blue Bird requested an oppor-
tunity to comment on the technical perfomiance
requirements of such a device before it becomes
a final rule.

Based on the above support for such a device,
the agency has concluded that a device to keep
floor-level emergency exit doors from shutting
after they have been opened is necessary on
school buses. The requirements specified in the
NPRM have been adopted. The technical require-
ments for this aspect of Standard No. 217 are
identical to those included in the NPRM. There-
fore, the agency does not believe the opportunity
requested by Blue Bird to review further the tech-
nical requirements of this device is merited.

]0. Improving the Conspiciiity of Emergency Exits
A number of commenters supported the pro-
posal to improve the conspicuity of emergency
exits. However, there were some differences of
opinion on how to accomplish the improved con-
spicuity. The NPRM proposed to require a 1-inch
wide strip of retroreflective tape to outline the
inside and outside perimeter of each designated
emergency exit opening. Additionally, the agency
sought comment on whether school buses should
be required to have an interior light source to illu-
minate the retroreflective tape around the interior
perimeter of emergency exits at night.

Blue Bird commented that it is "unaware of
any problems or concerns regarding emergency
exit identification or operating instructions under ^
the current exit requirements" and suggests that
NHTSA "establish and document a need for such
markings before including this requirement in the
final rule." It strongly recommended "that
NHTSA construct and evaluate prototype vehicles
and/or conduct field tests of this proposed
requirement before finalizing the rule." Thomas
Built also suggested that the effects of standard
interior lighting on driver's night vision be
studied. Transpec commented that reflective
markings of roof exits would "not be difficult to
accomplish" but questioned whether the need for
such markings had been "established" and said
that the "cost-effectiveness of such expenditures
might be questioned."

Minnesota did not believe retroreflective tape
should be required at emergency exits. First, it
noted that "(s)tudents usually ride the same bus
every day and usually during periods of time
when there is adequate light." Second, Minnesota
is "particularly concerned that reflective material
on the inside of the vehicle would create vision
problems for the driver at night. The light from --
oncoming vehicle headlights could reflect off the ^
material and back to the driver's eyes via the
inside mirror or the windshield."

Thomas Built also stated that since
retroreflective tape requires "a direct beam of
light originating from the point of the observer"
to function properly, it is unlikely that
retroreflective tape would perform well on the
inside of a school bus. "A stripe of fluorescent
paint would probably be more useful than the
reflective tape with respect to background lighting
without direct lighting." "Retroreflective tape
would work best on the outside of the exits where
it is likely to be illuminated by rescuers or pass-
ing car headlights." Several other commenters,
such as NSTA, West Virginia, and Salem-Keizer,
supported the use of reflective markings on emer-
gency exits.

Oregon supported making emergency exits
more visible, but believed that establishing a
"labeling criteria for emergency exits to include
a retroreflective background material" is better
than merely adding a 1-inch stripe of tape around
the perimeter of the exit. Even in no-light or lim- l

ited-light conditions, the words "Emergency "

Exit" would be at least as visible as currently

PART 571; S 217— PRE-34

required. It based this recommendation on the fact
that retroreflective tape is used for many other

) purposes around school buses in various states, as
well as on other vehicles, and it may not be clear
what the tape represents. Using retroreflective
tape to call attention to the words "Emergency
Exit" seemed more reasonable to Oregon.

Washington believed all emergency exits
should be identified on the interior and exterior,
and should be labelled with instructions for use.
"These instructions and location markings will
benefit students who walk to school and only ride
school buses on field trips and extracurricular
trips."

3M Traffic Control Materials Division [3M]
agreed with the proposal to provide retroreflective
markings at all emergency exits and provided the
necessary technical information, in terms of Mini-
mum Specific Intensity per Unit Area (SIA), for
the color yellow. The NPRM proposed to use the
intensities from Standard No. 125, Warning
Devices, which only covers the colors red and
white. 3M noted that the "(r)eflective emergency
exit markings visible from the exterior of the bus
have the other benefit of alerting motorists. This
^ provides an added benefit of accident preven-
I tion." However, 3M believed "a two inch wide
strip is needed (at the rear emergency exit) to pro-
vide the important added benefit of crash avoid-
ance made possible by making the vehicle visible
at greater distances by fast approaching motor
vehicles during times when headlights are being
used. This two inch strip is consistent with the
dimensions of other similar strips recommended
in the 1990 National Standards for School Buses
and Operations."

3M stated that "(w)hen retro-reflective mark-
ings are used in the interior of school buses
equipped with passenger compartment electric
lights, the reflective markings provide the added
benefit of enhancing identification of exits while
lights are operable. In situations where the electric
system fails to function during the post crash
situation, the reflective material will return light
to any light source within hundreds of feet of the
bus. Examples of these light sources include res-
cuer flashlights, street and building lights and
motor vehicles, to name only the most common
sources."
I Finally, 3M felt that the interior markings

' "would be considerably more valuable if the
markings were both retro-reflective and fluores-

cent and therefore highly visible even during all
light conditions without presence of a (sic) artifi-
cial light source of any kind."

After review of the above comments, the
agency has concluded that there are legitimate
concerns over the efficacy of requiring
retroreflective tape on the inside perimeters of
emergency exits. The agency believes that the
issues raised by Minnesota and Thomas Built,
with respect to mandatory interior lights and light
reflected into the eyes of the driver, are legiti-
mate. On the other hand, the agency has con-
cluded that retroreflective tape identifying the out-
side perimeter of emergency exits has significant
potential benefit, for both post crash rescue and
crash avoidance because of enhanced conspicuity
of the bus. Accordingly, the final rule requires a
minimum 1 inch wide strip of retroreflective tape,
either red, white, or yellow in color, to be placed
around the outside perimeter of the emergency
exit opening, not the emergency exit itself. The
required reflectivity properties of the tape will be
provided in a Table, consistent with the require-
ments for the reflective material allowed under
Standard No. 131, School Bus Pedestrian Safety
Devices.

1 1 . Hinge Placement for Roof Exits and Side

Emergency Exit Doors

The NPRM proposed that roof hatches be
hinged on the forward edge and that side emer-
gency exit doors be hinged on the forward edge,
as is currently required by Standard No. 217 for
a single left side door.

Transpec and NSTA supported the forward
hinging for roof hatches, and the agency has
adopted such a requirement in the final regulatory
language.

Thomas Built Buses noted an error in the pro-
posed wording of S5. 2. 3. 2(b) under Option B.
The proposed language required a left side emer-
gency door which is hinged on its "rearward"
side, rather than its "forward" side. This error is
corrected in the final regulatory language.

12. Warning Alarms for Roof Exits and Side

Emergency Exit Doors
The NPRM proposed that all emergency exits
be equipped with a continuous audible alarm at
the driver's position that sounds when the ignition
is in the "on" position and the emergency exit
release mechanism is not in the closed position.

PART 571: S 217— PRE-35

Transpec commented that roof exits do not
need to be equipped with alarm devices because:
(1) Roof exits are in "areas where it's virtually
impossible for passengers to lean against them
* * * let alone accidently fall through one;" (2)
unlatched roof exits (for ventilation purposes) are
seen in real-world operations, and an alarm
"could distract the driver's attention"; and (3)
"requiring alarms on roof exits will serve to
discourage retrofit installations of roof exits on
school buses * * * something that should be
encouraged."

The Arizona Department of Public Safety
[Arizona-DPS] forwarded a copy of their pro-
posed State school bus specifications which
include audible alarms for emergency exit doors
and emergency exit windows, as required by
Standard No. 217, but do not propose to require
audible alarms for roof exits.

California, NSTA, and Blue Bird expressed
support for audible alarms on emergency exit
doors and emergency exit windows.

The agency agrees with the comments by
Transpec and others, that there is no safety need
for an audible alarm on a roof exit. Unlike doors
or windows, it is unlikely that someone could
accidently fall out of the bus through a roof exit.
Additionally, the requirement for such a device
would make retrofitting of a roof exit signifi-
cantly more difficult. For these reasons, the final
regulatory language does not require an audible
alarm for roof exits.

13. Combination Roof Exits and Roof Ventilators
Transpec, California, and Iowa commented on
roof ventilators. Transpec stated its belief that the
standard should include a specification for a
"combination roof ventilator/exit," since that
would "result in a specification that coincides
with established industry practices." California
stated that "revisions to the roof exit language to
permit the use of the * * * (combination) roof
exit/vent is strongly encouraged." Finally,
because of the positive operational aspects of ven-
tilation roof hatches, Iowa believed that "(a)ny
standard that is established should not prohibit the
ability of the emergency roof escape system to
incorporate ventilation capability as an option."

The agency is not aware of any language in the
proposed standard that would have prohibited the
use of combination roof exit/vent units. Also, the
agency does not believe that there is any need to

create unique specifications for such combination
units. A combination exit vent should meet the
same requirements as a dedicated roof emergency M
exit.

14. Roof E.xit Release Mechanisms

The NPRM proposed that roof exits shall have
"a single locking mechanism which locks and
unlocks the roof exit with a single force applica-
tion not greater than 40 pounds." A number of
commenters objected to the single force applica-
tion requirement based on safety concerns.

Blue Bird noted that it had examined roof exit
designs which incorporated a single force applica-
tion device for unlatching the exit. Blue Bird
commented that "the proposed wording would
allow and possibly encourage roof exit latch
design that could function like crash-bars on audi-
torium doors. Latches that actuate by being
pushed in the direction of the initial push-out
motion of the exit could be knocked open
unintentionally in a rollover accident and occu-
pant ejection could result."

Thomas Built also requested a roof exit release
mechanism that is "similar to the rear push-out
window release requirement. Namely, that the ^
roof exit be releasable by not more than two %
mechanisms which do not have to be operated
simultaneously."

Transpec said that single force release mecha-
nisms "should not be used in vehicles where pas-
sengers can be thrown against them and ejected
accidently." Accordingly, Transpec suggested a
"double action" release mechanism for roof exits
rather than the proposed "single action" release
mechanism.

Finally, Oregon expressed its belief that a dou-
ble action latch for roof exits would be safer than
the single action latch that was proposed.

The agency agrees with the above comments
and is concerned about the potential for ejection
in a rollover if a single release mechanism is
allowed that will allow the roof exit to open upon
the application of force in the direction the roof
exit opens. Accordingly, the final regulatory lan-
guage adopts language similar to the existing
Standard No. 217 requirements for rear push-out
windows. Specifically, not more than two release
mechanisms can be used. The mechanism or, if
two mechanisms are used, each mechanism, shall ^
require either one or two force applications to
open. At least one of these force applications

PART 571; S 217— PRE-36

must differ from the direction of the initial push-
out motion by no less than 90 degrees and no
more than 180 degrees.

75. Wheelchair Lifts

Thomas Built Buses commented that many
school buses are equipped for wheelchair pas-
sengers, including the installation of a wheelchair
lift. It suggested that NHTSA "allow replacement
of one emergency door with a wheelchair lift
door if the bus is equipped with at least one
wheelchair placement."

There are two types of wheelchair lifts: passive
and active. Passive lifts are devices which are
normally located in an existing doorway used
both by persons with disabilities and those with-
out disabilities. When stowed, a passive lift
allows persons without disabilities the unimpeded
use of the door in which the lift is located. By
contrast, active lifts are devices that require a
separate opening in the bus body and which
impede the use of that opening when stowed.

The agency believes that doorways incorporat-
ing active lifts should be reserved for wheelchair-
bound or other disabled children who cannot eas-
ily use other exits on the bus. Additionally, the
agency notes that, if the bus driver is not avail-
able, it may not be as easy for a child to operate
an active lift to open the doorway, as it is for a
child to operate other emergency exit mecha-
nisms. Also, since active lifts take time to oper-
ate, they may not provide a sufficiently fast
means of emergency exit for a child without
disabilities.

Based on the above, the agency has concluded
that door openings that contain a passive lift
equipment can be used to fulfill the minimum
emergency exit requirements. However, openings
for active lifts cannot.

76. Title of Standard

The NPRM proposed to change the name of
Standard No. 217 to reflect more accurately the
scope and purpose of the standard. Only NSTA
and Washington commented on the proposal, and
both agreed with the change. Accordingly, the
final rule establishes a new title for Standard No.
217, Bus Emergency Exits and Window Retention
and Release.

17. Leadtime
The NPRM proposed an 18-month leadtime for
the effective date of any new school bus emer-

gency exit requirements. Because of its concerns
about structural fatigue from additional side emer-
gency exit doors, Thomas Built requested a two-
year leadtime. Blue Bird stated that the proposed
18-month lead time is adequate "providing no
new or unusual requirements are incorporated in
the final rule that are significantly different from
the proposals." Also, Blue Bird asserted that the
agency would need "to respond to requests for
interpretations or clarifications in a timely manner
and to make available associated test procedures
and references in a timely manner" if the 18-
month leadtime is to be acceptable.

Given the agency's conclusion that the Thomas
Built concerns over structural fatigue due to side
emergency exit doors are not significant (See Sec-
tion 2, Option A, Emergency Exit Doors, or
Option B, Doors and Roof Hatches), and the fact
that no more than two additional side emergency
exit doors would ever have to be installed on a
bus, the agency has concluded that an 18-month
leadtime is adequate.

This final rule does not have any retroactive
effect. Under section 103(d) of the National Traf-
fic and Motor Vehicle Safety Act (Safety Act; 15
U.S.C. 1392(d)), whenever a Federal motor
vehicle safety standard is in effect, a state may
not adopt or maintain a safety standard applicable
to the same aspect of performance which is not
identical to the Federal standard, except to the
extent that the state requirement imposes a higher
level of performance and applies only to vehicles
procured for the State's use. Section 105 of the
Safety Act (15 U.S.C. 1394) sets forth a proce-
dure for judicial review of final rules establishing,
amending or revoking Federal motor vehicle
safety standards. That section does not require
submission of a petition for reconsideration or
other administrative proceedings before parties
may file suit in court.

(Note: For the convenience of the reader, the pre-
amble uses U.S. units of weights and measurements
since these units were used in the NPRM. However,
pursuant to E.O. 12770 (56 F.R. 35801; July 29,
1991), the agency is in the process of converting all
safety standards to metric units. Therefore, metric
equivalents, rounded to the nearest whole unit, are
used in the regulatory text of this notice will be used
throughout future Standard No. 217 notices.)

In consideration of the foregoing, 49 CFR
571.217 is amended as follows:

PART 571; S 217— PRE-37

The title of Standard No. 217, Bus Window
Retention and Release, (49 CFR 571.217) is
revised to read as follows:

§571.217 Standard No. 217, Bus Emergency
Exits and Window Retention and Release.

Paragraph S4 of Standard No. 217 is amended
by adding the following definitions in alphabetical
order:

Daylight opening means the maximum unob-
structed opening of an emergency exit when
viewed from a direction perpendicular to the
plane of the opening.

Mid-point of the passenger compartment means
any point on a vertical transverse plane bisecting
the vehicle longitudinal centerline that extends
between the two vertical transverse planes which
define the foremost and rearmost limits of the
passenger compartment.

Passenger compartment means space within the
school bus interior that is between a vertical
transverse plane located 76 centimeters in front of
the forwardmost passenger seating reference point
and a vertical transverse plane tangent to the rear
interior wall of the bus at the vehicle centerline.

Post and roof how panel space means the area
between two adjacent post and roof bows.

4. Paragraph S5.2.3 of Standard No. 217 is
revised to read as follows:

S5.2.3 School buses. Each school bus shall
comply with S5.2.3.1 through S5.2.3.3.

S5.2.3.1 Each bus shall be equipped with the
exits specified in either S5.2.3.1(a) or S5. 2. 3. 1(b),
chosen at the option of the manufacturer. The
area in square centimeters of the unobstructed
openings for emergency exit shall collectively
amount to at least 170 times the number of des-
ignated seating positions in the bus. The amount
of emergency exit area credited to an emergency
exit is based on the daylight opening of the exit
opening.

(a)(1) One rear emergency door that opens out-
ward and is hinged on the right side (either side
in the case of a bus with a GVWR of 4,536 kilo-
grams or less), and exits providing an additional
emergency exit area (AEEA) calculated in accord-
ance with the following formula:

AEEA = [TA - FSDA - RDEA]

Where: ^

TA (total area) = 170 x number of designated seating
positions:

FSDA (front service door area) = size of the available
front service door opening; and

RDEA (rear door exit area) = size of the available rear
emergency exit door opening.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs (a)(2)
(i) through (iii) of this section, selected in the
sequence specified in those paragraphs —

(i) A left side emergency exit door that meets
the requirements of S5. 2. 3. 2(a);

(ii) An emergency roof exit that meets the
requirements of S5. 2. 3.2(b);

(iii) Any of the following types of exits, if nec-
essary to provide the AEEA: Side emergency exit
doors that meet the requirements of S5. 2. 3. 2(a),
emergency roof exits that meet the requirements
of S5. 2. 3. 2(b), or emergency window exits that
meet the requirements of S5. 2. 3. 2(c), at the option
of the manufacturer.

(b)(1) One emergency door on the vehicle's left ^
side that is hinged on its forward side and meets ^
the requirements of S5. 2. 3. 2(a), and a push-out
rear window that provides a minimum opening
clearance 41 centimeters high and 122 centimeters
wide and meets the requirements of S5.2.3.2(c),
and exits providing an additional emergency exit
area (AEEA) calculated in accordance with the
following formula:

AEEA=[TA— FSDA— SDEA— POWA]

Where:

TA (total area) = 170 x number of designated seating
positions;

FSDA (front service door area)=size of the available
front service door opening;

SDEA (side door exit area)=size of the available side
emergency exit door opening; and

POWA (push-out window area)=size of the available
rear emergency push-out window opening.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs

PART 57'.; S 217— PRE-38

(b)(2) (i) through (iii) of this section, selected in
"V. the sequence specified in those paragraphs —
))) (i) A right side emergency exit door that meets

the requirements of S5. 2. 3. 2(a);

(ii) An emergency roof exit that meets the
requirements of S5. 2. 3.2(b);

(iii) Any of the following types of exits, if nec-
essary to provide the AEEA; side emergency exit
doors that meet the requirements of S5. 2. 3.2(a),
emergency roof exits that meet the requirements
of S5. 2. 3. 2(b), or emergency window exits that
meets the requirements of S5. 2. 3. 2(c), at the
option of the manufacturer.

(c) The area of an opening equipped with a
wheelchair lift is counted toward meeting the
AEEA requirement under paragraph (a) or (b) of
this section only if the lift is of a design which
allows it to be folded or stowed in such a manner
that the area is available for use by persons not
needing the lift. The daylight opening of such an
exit is calculated with the lift in the folded or
stowed position.

S5.2.3.2 All emergency exits required by
S5.2.3.1(a) and S5.2.3.1(b) shall meet the follow-

l\ ing criteria:

' (a) Side emergency exit doors.

(1) Each side emergency exit door shall be
hinged on its forward side.

(2) A side emergency exit door installed pursu-
ant to S5.2.3.1(a)(2)(i) shall be located on the left
side of the bus and as near as practicable to the
midpoint of the passenger compartment. A single
side emergency exit door installed pursuant to
S5.2.3.1(a)(2)(iii) shall be located on the right
side of the bus. In the case of a bus equipped
with two emergency door exits pursuant to
S5.2.3.1(a)(2)(iii), the first shall be located on the
right side and the second on the left side of the
bus.

(3) A side emergency exit door installed pursu-
ant to S5.2.3.1(b)(2)(i) shall be located on the
right side of the bus. A single side emergency
exit door installed pursuant to S5.2.3.1(b)(2)(iii)
shall be located on the left side of the bus. In the
case of a bus equipped with two emergency door
exits pursuant to S5.2.3.1(b)(2)(iii), the first shall
be located on the left side and the second on the
right side of the bus.

' (4) No two side emergency exit doors shall be

located, in whole or in part, within the same post
and roof bow panel space.

(b) Ertiergency roof exit. ( 1 ) Each emergency
roof exit shall be hinged on its forward side, and
shall be operable from both inside and outside the
vehicle.

(2) In a bus equipped with a single emergency
roof exit, the exit shall be located as near as prac-
ticable to the midpoint of the passenger compart-
ment.

(3) In a bus equipped with two emergency roof
exits, one shall be located as near as practicable
to a point equidistant between the midpoint of the
passenger compartment and the foremost limit of
the passenger compartment and the other shall be
located as near as practicable to a point equi-
distant between the midpoint of the passenger
compartment and the rearmost point of the pas-
senger compartment.

(4) In a bus equipped with three or more emer-
gency roof exits, the roof exits shall be installed
so that, to the extent practicable, the longitudinal
distance between each pair of adjacent roof exits
is the same and equal to the distance from the
foremost point of the passenger compartment to
the foremost roof exit and to the distance from
the rearmost point of that compartment to the
rearmost roof exit.

(5) Except as provided in paragraph (b)(6) of
this section, each emergency roof exit shall be
installed with its longitudinal centerline coincid-
ing with a longitudinal vertical plane passing
through the longitudinal centerline of the school
bus.

(6) In a bus equipped with two or more emer-
gency roof exits, for each roof exit offset from
the longitudinal vertical plane specified in para-
graph (b)(5) of this section, there shall be another
roof exit offset from that plane an equal distance
to the other side.

(c) Emergency exit windows. A bus equipped
with emergency exit windows shall have an even
number of such windows, not counting a push-out
rear window required by S5. 2. 3. 1(b). Any side
emergency exit windows shall be evenly divided
between the right and left sides of the bus.

S5.2.3.3 The engine starting system of a bus
shall not operate if any emergency exit is locked
from either inside or outside the bus. For pur-
poses of this requirement, "locked" means that
the release mechanism cannot be activated and
the exit opened by a person at the exit without a
special device such as a key or special informa-
tion such as a combination.

PART 571; S 217— PRE-39

5. Paragraph S5.3.3 is revised to read as fol-
lows:

S5.3.3 School bus emergency exit release.

55.3.3.1 When tested under the conditions of S6,
both before and after the window retention test
required by S5.1, each school bus emergency exit
door shall allow manual release of the door by a
single person, from both inside and outside the
passenger compartment, using a force application
that conforms to paragraphs (a) through (c), except
a school bus with a GVWR of 4,536 kilograms or
less does not have to conform to paragraph (a).
The release mechanism shall operate without the
use of remote controls or tools, and notwithstand-
ing any failure of the vehicle's power system.
When the release mechanism is not in the position
that causes an emergency exit door to be closed
and the vehicle's ignition is in the "on" position,
a continuous warning sound shall be audible at the
driver's seating position and in the vicinity of that
emergency exit door.

(a) Location: Within the high force access
region shown in figure 3A for a side emergency
exit door, and in figure 3D for a rear emergency
exit door.

(b) Type of motion: Upward from inside the
bus; at the discretion of the manufacturer from
outside the bus. Buses with a GVWR of 4,536
kilograms or less shall provide interior release
mechanisms that operate by either an upward or
pull-type motion. The pull-type motion shall be
used only when the release mechanism is recessed
in such a manner that the handle, lever, or other
activating device, before being pulled, does not
protrude beyond the rim of the recessed recep-
tacle.

55.3.3.2 When tested under the conditions of S6.,
both before and after the window retention test
required by S5.1, each school bus emergency exit
window shall allow manual release of the exit by
a single person, from inside the passenger
compartment, using not more than two release
mechanisms located in specified low-force or
high-force regions (at the option of the manufac-
turer) with force applications and types of motions
that conform to either paragraph (a) or (b). In the
case of windows with one release mechanism, the

mechanism shall require two force applications to
open. In the case of windows with two release m
mechanisms, each mechanism shall require either ^
one or two force applications to open. At least one
of these force applications for each window shall
differ from the direction of the initial push-out
motion of the exit by no less than 90° and no
more than 180°. Each release mechanism shall
operate without the use of remote controls or
tools, and notwithstanding any failure of the
vehicle's power system. When the release mecha-
nism is open and the vehicle's ignition is in the
"on" position, a continuous warning shall be
audible at the driver's seating position and in the
vicinity of that emergency exit.

(a) Emergency exit windows — Low-force
application.

(1) Location: Within the low-force access
regions shown in Figures 1 and 3 for an emer-
gency exit window.

(2) Type of motion: Rotary or straight.

(3) Magnitude: Not more than 89 newtons.

(b) Emergency exit windows — High-force
application.

(1) Location: Within the high-force access
regions shown in Figures 2 and 3 for an emer- %
gency exit window.

(2) Type of motion: Straight and perpendicular
to the undisturbed exit surface.

(3) Magnitude: Not more than 178 newtons.

S5.3.3.3 When tested under the conditions of S6.,
both before and after the window retention test
required by S5.1, each school bus emergency roof
exit shall allow manual release of the exit by a
single person, from both inside and outside the
passenger compartment, using not more than two
release mechanisms located in specified low-force
or high-force regions (at the option of the manu-
facturer) with force applications and types of
motions that conform to either paragraph (a) or
(b). In the case of roof exits with one release
mechanism, the mechanism shall require two force
applications to open. In the case of roof exits with
two release mechanisms, each mechanism shall
require either one or two force applications to
open. At least one of these force applications for
each roof exit shall differ from the direction of the
initial push-out motion of the exit by no less than ^

90° and no more than 180°. ^

(a) Emergency roof exits — Low-force applica-

PART 57 i; S 217— PRE^O

(1) Location: Within the low-force access
regions shown in Figure 3B, in the case of buses
whose roof exits are not offset from the plane
specified in S5. 2. 3. 2(b)(5). In the case of buses
which have roof exits offset from the plane speci-
fied in S5.2.3. 2(b)(5), the amount of offset shall
be used to recalculate the dimensions in Figure
3B for the offset exits.

(2) Type of motion: Rotary or straight.

(3) Magnitude: Not more than 89 newtons.

(b) Emergency roof exits — High-force applica-
tion.

(1) Location: Within the high-force access
regions shown in Figure 3B, in the case of buses
whose roof exits are not offset from the plane
specified in S5. 2. 3. 2(b)(5). In the case of buses
which have roof exits offset from the plane speci-
fied in S5.2.3.2(b)(5), the amount of offset shall
be used to recalculate the dimensions in Figure
3B for the offset exits.

(2) Type of motion: Straight and perpendicular
to the undisturbed exit surface.

(3) Magnitude: Not more than 178 newtons.

6. Paragraph S5.4.2.1 is revised to read as fol-
lows:

S5.4.2.1 School buses with a GVWR of more than
4,536 kilograms.

(a) Emergency exit doors. After the release
mechanism has been operated, each emergency
exit door of a school bus shall, under the condi-
tions of S6., before and after the window reten-
tion test required by S5.1, using the force levels
specified in S5.3.3, be manually extendable by a
single person to a position that permits:

(1) In the case of a rear emergency exit door,
an opening large enough to permit unobstructed
passage of a rectangular parallelepiped 114 centi-
meters high, 61 centimeters wide, and 30 centi-
meters deep, keeping the 114 centimeter dimen-
sion vertical, the 61 centimeter dimension parallel
to the opening, and the lower surface in contact
with the floor of the bus at all times; and

(2) In the case of a side emergency exit door,
an opening at least 114 centimeters high and 61
centimeters wide.

(i) Except as provided in paragraph (a)(2)(ii) of
this section, no portion of a seat or a restraining
barrier shall be installed within the area bounded
by the opening of a side emergency exit door, a
vertical transverse plane tangent to the rearward
edge of the door opening frame, a vertical trans-

verse plane parallel to that plane at a distance of
30 centimeters forward of that plane, and a
longitudinal vertical plane passing through the
longitudinal centerline of the bus. (See Figure
5A.)

(ii) A seat bottom may be located within the
area described in paragraph (a)(2)(i) of this sec-
tion if the seat bottom pivots and automatically
assumes and retains a vertical position when not
in use, so that no portion of the seat bottom is
within the area described in paragraph (i) when
the seat bottom is vertical. (See Figure 5B.)

(iii) No portion of a seat or restraining barrier
located forward of the area described in paragraph
(a)(2)(i) of this section and between the door
opening and a longitudinal vertical plane passing
through the longitudinal centerline of the bus
shall extend rearward of a vertical transverse
plane tangent to the forwardmost portion of a
latch mechanism on the door. (See Figures 5B
and 5C.)

(3)(i) Each emergency exit door of a school
bus shall be equipped with a positive door open-
ing device that, after the release mechanism has
been operated, under the conditions of S6, before
and after the window retention test required by
S5.1—

(A) Bears the weight of the door;

(B) Keeps the door from closing past the point
at which the door is perpendicular to the side of
the bus body, regardless of the body's orientation;
and

(ii) The positive door opening device shall per-
form the functions specified in paragraphs
(a)(3)(i) (A) and (B) of this section without the
need for additional action beyond opening the
door past the point at which the door is per-
pendicular to the side of the bus body.

(b) Emergency roof exits. After the release
mechanism has been operated, each emergency
roof exit of a school bus shall, under the condi-
tions of S6, before and after the window retention
test required by S5.1, using the force levels speci-
fied in S5.3.3, be manually extendable by a single
person to a position that permits an opening at
least 41 centimeters high and 41 centimeters
wide.

7. Paragraph S5.5.32 is revised to read as fol-
lows:

PART 571; S 217— PRE^l

S5.5.3 School bus.

(a) Each school bus emergency exit provided in
accordance with S5.2.3.1 shall have the designa-
tion "Emergency Door" or "Emergency Exit,"
as appropriate, in letters at least 5 centimeters
high, of a color that contrasts with its back-
ground. For emergency exit doors, the designation
shall be located at the top of, or directly above,
the emergency exit door on both the inside and
outside surfaces of the bus. The designation for
roof exits shall be located on an inside surface of
the exit, or within 30 centimeters of the roof exit
opening. For emergency window exits, the des-
ignation shall be located at the top of, or directly
above, or at the bottom of the emergency window
exit on both the inside and outside surfaces of the
bus.

(b) Concise operating instructions describing
the motions necessary to unlatch and open the
emergency exit shall be located within 15 centi-

meters of the release mechanism on the inside
surface of the bus. These instructions shall be in
letters at least 1 centimeter high and of a color
that contrasts with its background.
Example:

(1) Lift to Unlatch, Push to Open

(2) Turn Handle, Push Out to Open

(c) Each opening for a required emergency exit
shall be outlined around its outside perimeter with
a minimum 3 centimeters wide retroreflective
tape, either red, white, or yellow in color, that,
when tested under the conditions specified in S6. 1
of 571.131, meets the criteria specified in Table
1.

Issued on October 27, 1992.

Howard M. Smolkin,
Executive Director.

57 F.R, 49413
November 2, 1992

PART 571; S 217— PRE^2

PREAMBLE TO AN AMENDMENT TO FEDERAL MOTOR VEHICLE SAFETY

STANDARD NO. 217

Bus Emergency Exits and Window Retention and Release

(Docket No. 88-21 ; Notice 5)

ACTION: Final rule; technical amendment.

SUMMARY: This rule corrects an error made in a
November 2, 1992, final rule amending Federal
Motor Vehicle Safety Standard No. 217, Bus
Emergency Exits and Window Retention and
Release. The conversion to metric units of the for-
mula for determining the amount of exit area
which must be provided was incorrectly per-
formed. In addition, a table and three figures
referred to in the regulatory language of the final
rule were omitted.

EFFECTIVE DATE: The amendment made by this
rule is effective May 2, 1994.

SUPPLEMENTARY INFORMATION: On Novem-
ber 2, 1992, NHTSA issued a final rule amending
Federal Motor Vehicle Safety Standard No. 217,
Bus Emergency Exits and Window Retention and
Release, to revise the minimum requirements for
school bus emergency exits, to improve access to
school bus emergency doors, and to improve the
visibility of school bus emergency exits.

This notice corrects several errors in that final
rule. First, pursuant to E.O. 12770, Metric Usage
in Federal Government Programs (56 F.R. 35801;
July 29, 1991), the agency is in the process of
converting all safety standards to metric units.
Therefore, metric equivalents, rounded to the
nearest whole unit, were used in the regulatory
test of the final rule. However, the formula for
determining the amount of exit area which must
be provided was incorrectly converted. The notice
of proposed rulemaking preceding the recent final
rule proposed to require that school buses provide
minimum emergency exit spaces which together
are equal, in square inches, to 67 times the num-
ber of seating positions. This formula was erro-
neously converted in the final rule to centimeters,
not square centimeters. The final rule should have
specified that school buses are required to provide
minimum emergency exit spaces which together

are equal in square centimeters, to 432 times the
number of seating position, not 170 times the
number of seating positions. (Note: A notice of
proposed rulemaking published the same day as
the final rule also erroneously used the latter fig-
ure (57 FR 49444). If a final rule is issued based
on that notice, the correct figure will be used.)

Second, as part of the final rule, S5.4.2. 1(a)(2)
was amended to specify a zone which must be
kept clear to provide access to a side emergency
door. The regulatory language refers to three fig-
ures. Figure 5A, Figure 5B, and Figure 5C, which
illustrate these requirements. These figures were
omitted from the copies of the final rule sent to
the Federal Register. The final rule also amended
S5.5.3(c) to require marking of emergency exits
with retroreflective tape which meets intensity cri-
teria specified in Table 1. Table 1 was also omit-
ted from the final rule.

This correction imposes no duties or respon-
sibilities on any party not already imposed by the
final rule. Discussion in the preamble to the final
rule makes it clear that the agency did not intend
to change the formula and that the error was
merely a conversion error. The figures and table
clarify obligations imposed by the final rule.
Accordingly, NHTSA finds for good cause that
notice and opportunity for comments are nec-
essary.

In consideration of the foregoing, 49 CFR
S571.217 is amended as follows:

1. Paragraph S5.2.3.1 of Standard No. 217 is
revised to read as follows:

S5.2.3.1 Each bus shall be equipped with the exits
specified in either §5.2.3. 1(a) or § 5.2.3.1(b), cho-
sen at the option of the manufacturer. The area in
square centimeters of the unobstructed openings
for emergency exits shall collectively amount to at
least 432 times the number of designated seating
positions in the bus. The amount of emergency

PART 571: S 217— PRE^3

exit area credited to an emergency exit is based on
the daylight opening of the exit opening.

(a)(1) One rear emergency door that opens out-
ward and is hinged on the right side (either side
in the case of a bus with a GVWR of 4.536 kilo-
grams or less), and exits providing an additional
emergency exit area (AEEA) calculated in accord-
ance with the following formula:
AEEA=[TA-FSDA-RDEA]

Where:

TA (total area)=432 x number of designated
seating positions;

FSDA (front service door area)=size of the
available front service door opening; and

RDEA (rear door exit area)=size of the avail-
able rear emergency exit door opening.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs (i)
through (iii) of this section, selected in the
sequence specified in those paragraphs —

(i) A left side emergency exit door that
meets the requirements of S5. 2. 3. 2(a);

(ii) An emergency roof exit that meets the
requirements of S5. 2. 3.2(b);

(iii) Any of the following types of exits, if
necessary to provide the AEEA: Side emer-
gency exit doors that meet the requirements of
S5.2.3.2(a), emergency roof exits that meet the
requirements of S5. 2. 3.2(b), or emergency win-
dow exits that meet the requirements of
S5.2.3.2(c), at the option of the manufacturer.
(b)(1) One emergency door on the vehicle's left
side that is hinged on its forward side and meets
the requirements of S5. 2. 3. 2(a), and a push-out
rear window that provides a minimum opening
clearance 41 centimeters high and 122 centimeters
wide and meets the requirements of S5. 2. 3.2(c),
and exits providing an additional emergency exit
area (AEEA) calculated in accordance with the
following formula:

AEEA=(TA-FSDA-SDEA-POWA)

Where:

TA (total area)=432 x number of designated ,
seating positions; C

FSDA (front service door area)=size of the
available front service door opening;

SDEA (side door exit area)=size of the avail-
able side emergency exit door opening; and

POWA (push-out window area)=size of the
available rear emergency push-out window
opening.

(2) These exits installed to provide the
AEEA shall be of the types specified in para-
graphs (i) through (iii) of this section, selected in
the sequence specified in those paragraphs —

(i) A right side emergency exit door that
meets the requirements of § 5.2.3.2(a);

(ii) An emergency roof exit that meets the
requirements of S5. 2. 3. 2(b);

(c) The area of an opening equipped with a
wheelchair lift is counted toward meeting the
AEEA requirement under paragraph (a) or (b) of
this section only if the lift is of a design that
allows it to be folded or stowed in such a manner
that the area is available for use by persons not
needing the lift. The daylight opening of such an
exit is calculated with the lift in the folder or
stowed position.

2. New Figures 5A, 5B, and 5C are added, to
appear following Figure 4 at the end of S571.217,
as follows:

3. New Table 1 is added, to appear following
Figure 5C at the end of S571.217, as follows:

Issued on: November 24, 1992.

Front

Sides of Bus Body

Side Emergency
Exit Door

30 cm
Minimum

Centerllne of Bus

Figure 5A

PART 571; S 217— PRE-45

Figure 5B

Figure 5C

PART 571; S 217— PRE-46

Table 1. Minimum Specific Intensity Per Unit Area (SIA)

(Candelas per Footcandle Per Square Foot)
Type III Retroreflective Material

A— Glass Bead Retroreflective Element Material

Observation Angle (°)

Entrance Angle (°)

White

Red

Yellow

0.2
0,2
0.5
0.5

-4
+30

250
150
95
65

45
25
15
10

170
100
62
45

B— Prismatic Retroreflective Element Material

Observation

Angle n

Entrance Angle (°)

White

Red

Yellow

0.2
0.2
0.5
0.5

-4
+30

250
95

200
65

45
13.3
28
10

170
64
136

Marion C. Blakey,
Administrator

57 F.R. 57020
December 2, 1992

PART 571: S 217— PRE^7

MOTOR VEHICLE SAFETY STANDARD NO. 217

Bus Window Retention and Release
[Bus Emergency Exits and Window Retention and Release]*

51. Scope. This standard establishes require-
ments for the retention of windows other than
windshields in buses, and establishes operating
forces, opening dimensions, and markings for
push-out bus windows and other emergency exits.

52. Purpose. The purpose of this standard is to
minimize the likelihood of occupants being
thrown from the bus and to provide a means of
readily accessible emergency egress.

53. Application. This standard applies to buses,
except buses manufactured for the purpose of
transporting persons under physical restraint.

54. Definitions.

Adjacent seat means a designated seating posi-
tion located so that some portion of its occupant
space is not more than 10 inches from an emer-
gency exit, for a distance of at least 15 inches
measured horizontally and parallel to the exist.

[Daylight opening means the maximum unob-
structed opening of an emergency exit when
viewed from a direction perpendicular to the
plane of the opening.'\

[Mid-point of the passenger compartment
means any point on a vertical transverse plane
bisecting the vehicle longitudinal centerline that
extends between the two vertical transverse
planes which define the foremost and rearmost
limits of the passenger compartment.^

Occupant space means the space directly above
the seat and footwell, bounded vertically by the
ceiling and horizontally by the normally posi-
tioned seat back and the nearest obstruction of
occupant motion in the direction the seat faces.

[Passenger compartment means space within
the school bus interior that is between a vertical
transverse plane located 76 centimeters in front
of the forn'ardmost passenger seating reference
point and a vertical transverse plane tangent to
the rear interior wall of the bus at the vertical
centerline.}

[Post and roof bow panel space means the
area between tn'o adjacent post and roof bows.}

Push-out window means a vehicle window
designed to open outward to provide for emer-
gency egress. [(57 F.R. 49413 — November 2,
1992 Effective: May 2, 1994]

S5. Requirements.

S5.1 Window retention. Except as provided in
S5.1.2, each piece of window glazing and each
surrounding window frame, when tested in accord-
ance with the procedure in S5.1.1 under the condi-
tions of S6.1 through S6.3, shall be retained by its
surrounding structure in a manner that prevents
the formation of any opening large enough to
admit the passage of a 4-inch diameter sphere
under a force, including the weight of the sphere,
of 5 pounds until any one of the following events
occurs:

(a) A force of 1200 pounds is reached.

(b) At least 80% of the glazing thickness has
developed cracks running from the load contact
region to the periphery at two or more points, or
shattering of the glazing occurs.

(c) The inner surface of the glazing at the cen-
ter of force application has moved relative to the
window frame along a line perpendicular to the
undisturbed inner surface, a distance equal to one-
half of the square root of the minimum surface
dimension measured through the center of the
area of the entire sheet of window glazing.

55.1.1 An increasing force shall be applied to the
window glazing through the head form specified
in Figure 4, outward and perpendicular to the
undisturbed inside surface at the center of the area
of each sheet of window glazing, with a head form
travel of 2 inches per minute.

55.1.2 The requirements of this standard do not
apply to a window whose minimum surface

[Effective: May 2, 1994]

PART 571

dimension measured througii the center of its area
is less tiian 8 inches.

S5.2 Provision of emergency exits. Buses
other than school buses shall provide unobstructed
openings for emergency exit which collectively
amount, in total square inches, to at least 67 times
the number of designated seating positions on the
bus. At least 40 percent of the total required area
of unobstructed openings, computed in the above
manner, shall be provided on each side of a bus.
However, in determining the total unobstructed
openings provided by a bus, no emergency exit,
regardless of its area, shall be credited with more
than 536 square inches of the total area require-
ment. School buses shall provide openings for
emergency exits that confomi to S5.2.3.

55.2.1 Buses witii a GVWR of more than
10,000 pounds. Except as provided in S5.2.1.1,
buses with a GVWR of more than 10,000 pounds
shall meet the unobstructed openings requirements
by providing side exits and at least one rear exit
that conforms to S5.3 through S5.5. The rear exit
shall meet the requirements when the bus is
upright and when the bus is overturned on either
side, with the occupant standing facing the exit.
When the bus configuration precludes installation
of an accessible rear exit, a roof exit that meets
the requirements of S5.3 through S5.5 when the
bus is overturned on either side, with the occupant
standing facing the exit, shall be provided in the
rear half of the bus.

S5.2.1.1 A bus with GVWR of more than 10,000
pounds may satisfy the unobstructed openings
requirement by providing at least one side door for
each three passenger seating positions in the
vehicle.

55.2.2 Buses with a GVWR of 10,000 pounds
or less. Buses with a GVWR of 10.000 pounds
or less may meet the unobstructed openings
requirement by providing:

(a) Devices that meet the requirements of S5.3
through S5.5 without using remote controls or
central power systems;

(b) Windows that can be opened manually to a
position that provides an opening large enough to
admit unobstructed passage, keeping a major axis
horizontal at all times, of an ellipsoid generated
by rotating about its minor axis an ellipse having

a major axis of 20 inches and a minor axis of 13
inches; or

S5.2.3 School buses.

S5.2.3.1 l_Each bus shall be equipped with the
exits specified in either §5.2.3. 1(a) or §5.2.3. 1(b),
chosen at the option of the manufacturer. The
area in square centimeters of the unobstructed
openings for emergency exit shall collectively
amount to at least 432 times the number of des-
ignated seating positions in the bus. The amount
of emergency exit area credited to an emergency
exit is based on the daylight opening of the exit
opening.

(a)(1) One rear emergency door that opens
outn'ard and is hinged on the right side (either
side in the case of a bus with a GVWR of 4.536
kilograms or less), and exits providing an addi-
tional emergency exit area (AEEA) calculated in
accordance with the following formula:
AEER=[TA-FSDA-RDEA]

Where:

TA (total area)=432 x number of designated
seating positions: ^

FSDA (front service door area)=size of the ^
available front service door opening: and

RDEA (rear door exit area)=size of the

available rear emergency exit door opening.

(2)The exits installed to provide the AEEA

shall be of the types specified in paragraphs (i)

through (Hi) of this section, selected in the

sequence specified in those paragraphs —

(i)A left side emergency exit door that meets
the requirements of §5. 2. 3. 2(a):

(ii) An emergency roof e.xit that meets the
requirements of §5. 2. 3. 2(b):

(Hi) Any of the following types of exits, if
necessary to provide the AEEA: Side emer-
gency exit doors that meet the requirements of
§ 5.2.3.2(a), emergency roof exits that meet the
requirements of §5. 2. 3. 2(b), or emergency win-
dow exits that meet the requirements of
§ 5.2.3.2(c), at the option of the manufacturer.
(b)(1) One emergency door on the vehicle's left
side that is hinged on its forward side and meets
the requirements of §5.2.3.2(a), and a push-out
rear window that provides a minimum opening A
clearance 41 centimeters high and 122 centi- W
meters wide and meets the requirements of

Rev. 11/2/92

PART 571; S 217-2

§ 5.2.3.2(c). and exits providing an additional
emergency exit area (AREA) calculated in
J accordance with the following formula:
AEEA=(TA-FSDA-SDEA-POWA)

Where:

TA (total area)=432 x number of designated
seating positions;

FSDA (fi-ont service door area)-size of the
available font serxice door opening;

SDEA (side door exit area)=size of the avail-
able side emergency exit door opening; and

POWA (push-out window area)=size of the
available rear emergency push-out window
opening.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs (i)
through (Hi) of this section, selected in the
sequence specified in those paragraphs —

(i) A right side emergency exit door that
meets the requirements of §5. 2. 3. 2(a);

(ii) An emergency roof exit that meets the
requirements of § 5.2.3.2(b);

(Hi) Any of the following types of exits, if
\ necessary to provide the AEEA: Side emer-

gency exit doors that meet the requirements of
§ 5.2.3.2(a), emergency roof exits that meet the
requirements of §5. 2. 3. 2(b). or emergency win-
dow exits that meet the requirements of
§ 5.2.3.2(c), at the option of the manufacturer.

S5.2.3.2 The engine starting system of a school
bus shall not operate if any emergency door is
locked from either inside or outside the bus. For
purposes of this requirement, "locked" means
that the release mechanism cannot be activated by
a person at the door without a special device such
\ as a key or special information such as a combina-
tion.

S5.3 Emergency exit release.

55.3.1 Each push-out window or other emergency
exit not required by S5.2.3 shall be releasable by
operating one or two mechanisms located within
the regions specified in Figures 1, 2, and 3. The
lower edge of the region in Figure 1 and Region
B in Figure 2, shall be located 5 inches above the
adjacent seat, or 2 inches above the armrest, if
any, whichever is higher.

55.3.2 When tested under the conditions of S6,
both before and after the window retention test
required by S5.1, each emergency exit not
required by S5.2.3 shall allow manual release of
the exit by a single occupant using force applica-
tions each of which conforms, at the option of the
manufacturer, either to (a) or (b). The release
mechanism or mechanisms shall require for
release one or two force applications, at least one
of which differs by 90 to 180° from the direction
of the initial push-out motion of the emergency
exit (outward and perpendicular to the exit sur-
face).

(a) Low-force application.

Location: As shown in Figure 1 or Figure 3.
Type of Motion: Rotary or straight.
Magnitude: Not more than 20 pounds.

(b) High force application.

Location; As shown in Figure 2 or Figure 3.
Type of Motion: Straight, perpendicular to the
undisturbed exit surface.

Magnitude: Not more than 60 pounds.

55.3.3 When tested under the conditions of S6,
both before and after the window retention test
required by S5.1, each school bus emergency door
shall allow manual release of the door by a single
person, from both inside and outside the bus pas-
senger compartment, using a force application that
conforms to paragraphs (a) through (c) except a
school bus with a GVWR of 10,000 pounds or
less does not have to conform to paragraph (a).
Each release mechanism shall operate without the
use of remote controls or tools, and notwithstand-
ing any failure of the vehicle's power system.
When the release mechanism is not in the closed
position and the vehicle ignition is in the "on"
position, a continuous warning sound shall be
audible at the driver's seating position and in the

PART 571; S 217-3

(Rev. 11/2/92)

vicinity of the emergency door having the
unclosed mechanism.

(a) Location: Within the high force access
region shown in Figure 3A for a side emergency
door, and in Figure 3D for a rear emergency door.

(b) Type of motion: Upward from inside the
bus; at the discretion of the manufacturer from
outside the bus. Buses with a GVWR of 10,000
pounds or less shall provide interior release
mechanisms that operate by either an upward or
pull-type motion. The pull-type motion shall be
used only when the release mechanism is recessed
in such a manner that the handle, lever, or other
activating device does not protrude beyond the
rim of the recessed receptacle.

The present S5.4 is renumbered S5.4.1, and the
phrase "Each push-out window or other emer-
gency exit shall, after the release mechanism has
been operated," is replaced by the phrase "After
the release mechanism has been operated, each
push-out window or other emergency exit not
required by S5.2.3," at the beginning of the para-
graph.

l_S5.2.3 School buses. Each school bus shall com-
ply with S5.2.3.1 through S5.2.3.3.

S5.2.3.1 Each bus shall be equipped with the
exists specified in either S5.2.3.1(a) or
S5. 2.3. lib), chosen at the option of the manufac-
turer. The area in square centimeters of the unob-
structed openings for emergency exit shall collec-
tively amount to at least 170 times the number of
designated seating positions in the bus. The
amount of emergency exit area credited to an
emergency exit is based on the daylight opening
of the exit opening.

(a)(1) One rear emergency door that opens
outward and is hinged on the right side (either
side in the case of a bus with a GVWR of 4,536
kilograms or less), and exits providing an addi-
tional emergency exit area (AEEA) calculated in
accordance with the following formula:
AEEA=[TA - FSDA - RDEA]
Where:

TA (total area) - 170 x number of designated
seating positions;

FSDA (front service door area) = size of the
available front service door opening; and
RDEA (rear door exit area) = size of the avail-
able rear emergency exit door opening.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs
(a)(2) (i) through (Hi) of this section, selected in ^
the sequence specified in those paragraphs —

(i) A left side emergency exit door that meets
the requirements of S5. 2. 3. 2(a):

(ii) An emergency roof exit that meets the
requirements of S5. 2. 3. 2(b);

(Hi) Any of the following types of exits, if nec-
essary to provide the AEEA: Side emergency exit
doors that meet the requirements of S5.2.3.2(a),
emergency roof exits that meet the requirements
of S5.2.3.2(b), or emergency window exits that
meet the requirements of S5.2.3.2(c), at the option
of the manufacturer.

(b)(1) One emergency door on the vehicle's left
side that is hinged on its forn'ard side and meets
the requirements of S5.2.3.2(a), and a push-out
rear window that provides a minimum opening
clearance 41 centimeters high and 122 centi-
meters wide and meets the requirements of
S5.2.3.2(c), and exits providing an additional
emergency exit area (AEEA) calculated in
accordance with the following formula:

AEEA=[TA - FSDA - SDEA - POWA] -

Where: K

TA (total area) = 170 x number of designated
seating positions;

FSDA (front sen'ice door area)=size of the
available front sen'ice door opening;

SDEA (side door exit area)=size of the avail-
able side emergency exit door opening; and

POWA (push-out window area)=size of the
available rear emergency push-out window open-
ing.

(2) The exits installed to provide the AEEA
shall be of the types specified in paragraphs
(b)(2) (i) through (Hi) of this section, selected in
the sequence specified in those paragraphs —

(i) A right side emergency exit door that meets
the requirements of S5. 2.3. 2(a);

(ii) An emergency roof exit that meets the
requirements of S5 .2 .3 .2(b) ;

(Hi) Any of the following types of exits, if nec-
essary to provide the AEEA: side emergency exit
doors that meet the requirements of S5.2.3.2(a),
emergency roof exits that meet the requirements
of S5.2.3.2(b), or emergency window exits that dL
meets the requirements of S5.2.3.2(c), at the ^
option of the manufacturer.

(Rev. 11/2/92)

PART 571: S 217-4

S5.2.3.2 All emergency exits required by
S5.2.3.1(a) and S5.2.3.J(b) shall meet the follow-
ing criteria:

(a) Side emergency exit doors.

(1) Each side emergency exit door shall he
hinged on its forward side.

(2) A side emergency exit door installed pursu-
ant to S5.2.3.1(a)(2)(i) shall be located on the left
side of the bus and as near as practicable to the
midpoint of the passenger compartment. A single
side emergency exit door installed pursuant to
S5.2.3.](a)(2)(iii) shall be located on the right
side of the bus. In the case of a bus equipped
with two emergency door exits pursuant to
S5.2.3.1(a)(2)(iii), the first shall be located on the
right side and the second on the left side of the
bus.

(3) A side emergency exit door installed pursu-
ant to S5.2.3.](b)(2)(i) shall be located on the
right side of the bus. A single side emergency exit
door installed pursuant to S5.2.3.1(b)(2)(iii) shall
be located on the left side of the bus. In the case
of a bus equipped with two emergency door exits
pursuant to S5.2.3.1(b)(2)(iii). the first shall be
located on the left side and the second on the
right side of the bus.

(4) No two side emergency exit doors shall be
located, in whole or in part, within the same post
and roof bow panel space.

(b) Emergency roof exit. (I) Each emergency
roof exit shall be hinged on its forward side, and
shall be operable from both inside and outside
the vehicle.

(2) In a bus equipped with a single emergency
roof exit, the exit shall be located as near as
practicable to the midpoint of the passenger
compartment.

(3) In a bus equipped with mo emergency roof
exits, one shall be located as near as practicable
to a point equidistant between the midpoint of the
passenger compartment and the foremost limit of
the passenger compartment and the other shall be

located as near as practicable to a point equi-
distant between the midpoint of the passenger
compartment and the rearmost point of the pas-
senger compartment.

(6) In a bus equipped with mo or more emer-
gency roof e.xits. for each roof exit offset from the
longitudinal vertical plane specified in paragraph
(b)(5) of this section, there shall be another roof
exit offset from that plane an equal distance to
the other side.

(c) Emergency exit windows. A bus equipped
with emergency exit windows shall have an even
number of such windows, not counting a push-out
rear window required by S5.2.3.1(b). Any side
emergency exit windows shall be evenly divided
between the right and left sides of the bus.

S5.2.3.3 The engine starting system of a bus shall
not operate if any emergency exit is locked from
either inside or outside the bus. For purposes of
this requirement, "locked" means that the release
mechanism cannot be activated and the exit
opened by a person at the exit without a special
device such as a key or special information such
as a combination. (57 F.R. 49413-November 2,
1992. Effective: May 2, 1994.)]

[S5.3.3 School bus emergency exit release.

S5.3.3.1 When tested under the conditions of S6.,
both before and after the window retention test
required by S5.I, each school bus emergency exit
door shall allow manual release of the door by a
single person, from both inside and outside the
passenger compartment, using a force application
that conforms to paragraphs (a) through (c).
except a school bus with a GVWR of 4.536 kilo-

PART571; S 217-5

(Rev. 11/2/92)

grams or less does not have to conform to para-
graph (a). The release mechanism shall operate
without the use of remote controls or tools, and
notwithstanding any failure of the vehicle's power
system. When the release mechanism is not in the
position that causes an emergency exit door to be
closed and the vehicle's ignition is in the "on"
position, a continuous warning sound shall be
audible at the driver's seating position and in the
vicinity of that emergency exit door.

(a) Location: Within the high force access
region shown in Figure 3 A for a side emergency
exit door, and in figure 3D for a rear emergency
exit door.

S5.3.3.2 When tested under the conditions of S6..
both before and after the window retention test
required by 55.7, each school bus emergency exit
window shall allow manual release of the exit by
a single person, from inside the passenger
compartment, using not more than two release
mechanisms located in specified low-force or
high-force regions (at the option of the manufac-
turer) with force applications and types of motions
that conform to either paragraph (a) or (b). In the
case of windows with one release mechanism, the
mechanism shall require two force applications to
open. In the case of windows with two release
mechanisms, each mechanism shall require either
one or two force applications to open, at least one
of these force applications for each window shall
dijfer from the direction of the initial push-out
motion of the exit by no less than 90° and no more
than 180°. Each release mechanism shall operate
without the use of remote controls or tools, and
not withstanding any failure of the vehicle's power
system. When the release mechanism is open and
the vehicle's ignition is in the "on" position, a
continuous warning shall be audible at the driv-

er's seating position and in the vicinity of that
emergency exit.

(a) Emergency exit windows — Low-force
application. ^^

(1) Location: Within the low-force access
regions shown in Figures 1 and 3 for an emer-
gency exit window.

(2) Type of motion: Rotaiy or straight.

(3) Magnitude: Not more than 89 newtons.

(b) Emergency exit windows — High-force
application.

(1) Location: Within the high-force access
regions shown in Figures 2 and 3 for an emer-
gency exit window.

(2) Type of motion: Straight and perpendicular
to the undisturbed exit surface.

(3) Magnitude: Not more than 178 newtons.

S5.3.3.3 When tested under the conditions of S6.,
both before and after the window retention test
required by 55.7, each school bus emergency roof
exit shall allow manual release of the exit by a
single person, from both inside and outside the
passenger compartment, using not more than two
release mechanisms located in specified low-force
or high-force regions (at the option of the manu-
facturer) with force applications and types of ^
motions that conform to either paragraph (a) or
(b). In the case of roof exits with one release
mechanism, the mechanism shall require two force
applications to open. In the case of roof exits with
n\'o release mechanisms, each mechanism shall
require either one or tn>o force applications to
open. At least one of these force applications for
each roof exit shall dijfer from the direction of the
initial push-out motion of the exit by no less than
90° and no more than 180°.

(a) Emergency roof exits — Low-force applica-
tion.

(1) Location: Within the low force access
regions shown in Figure 3B, in the case of buses
whose roof exits are not offset from the plane
specified in S5. 2. 3. 2(b)(5). In the case of buses
which have roof exits offset from the plane speci-
fied in S5. 2. 3. 2(b)(5), the amount of offset shall
be used to recalculate the dimensions in Figure
38 for the offset exits.

(2) Type of motion: Rotary or straight.

(3) Magnitude: Not more than 89 newtons.

(b) Emergency roof exits — High-force applica- ^
tion.

(Rev. 11/2/92)

PART 571; S 217-6

(1) Location: Within the high force access
regions shown in Figure SB, in the case of buses

"\ whose roof exits are not offset from the plane
) specified in S5.2.3.2(b)(5). In the case of buses
which have roof exits offset from the plane speci-
fied in S5.2.3.2(b)(5), the amount of offset shall
be used to recalculate the dimensions in Figure
3B for the offset exits.

(2) Type of motion: Straight and perpendicular
to the undisturbed exit surface.

(3) Magnitude: Not more than 178 newtons.
(57 FR 49413— November 2, 1992. Effective:
May 2, 1994]

S5.4 Emergency exit extension.

55.4.1 After the release mechanism has been oper-
ated, each push-out window or other emergency
exit not required by S5.2.3 shall, under the condi-
tions of S6, before and after the window retention
test required by S5.1, using the reach distances
and corresponding force levels specified in S5.3.2,
be manually extendable by a single occupant to a
position that provides an opening large enough to
admit unobstructed passage, keeping a major axis

^ horizontal at all times, of an ellipsoid generated by
rotating about its minor axis an ellipse having a
major axis of 20 inches and a minor axis of 13
inches.

55.4.2 School bus emergency exit extension.

S5.4.2.1 School bus with a GVWR of more
than 10,000 pounds. After the release mechanism
has been operated, the emergency door of a school
bus with a GVWR of more than 10,000 pounds
shall, under the conditions of S6, before and after
the window retention test required by S5.1, using
the force levels specified in S5.3.3, be manually
extendable by a single person to a position that
permits —

(a) In the case of rear emergency door, an
opening large enough to permit unobstructed pas-
sage of a rectangular parallelepiped 45 inches
high, 24 inches wide, and 12 inches deep, keeping
the 45-inch dimension vertical, the 24-inch
dimension parallel to the opening, and the lower
surface in contact with the floor of the bus at all
times; and

)(b) In the case of a side emergency door, an
opening at least 45 inches high and 24 inches
wide. A vertical transverse plane tangent to the

rearmost point of a seat back shall pass through
the forward edge of a side emergency door.

[S5.4.2.1 School buses with a GVWR of more
than 4,536 kilograms.

(1) In the case of a rear emergency exit door,
an opening large enough to permit unobstructed
passage of a rectangular parallelepiped 114
centimeters high, 61 centimeters wide, and 30
centimeters deep, keeping the 114 centimeter
dimension vertical, the 61 centimeter dimension
parallel to the opening, and the lower surface in
contact with the floor of the bus at all times; and

(2) In the case of a side emergency exit door,
an opening at least 114 centimeters high and 61
centimeters wide.

(i) Except as provided in paragraph (a)(2)(ii)
of this section, no portion of a seat or a restrain-
ing barrier shall be installed within the area
bounded by the opening of a side emergency exit
door, a vertical transverse plane tangent to the
reai-H'ard edge of the door opening frame, a verti-
cal transverse plane parallel to that plane at a
distance of 30 centimeters fo)-ward of that plane,
and a longitudinal vertical plane passing through
the longitudinal centerline of the bus. (See Figure
5 A).

(ii) A seat bottom may be located within the
area described in paragraph (a)(2)(i) of this sec-
tion if the seat bottom pivots and automatically
assumes and retains a vertical position when not
in use. so that no portion of the seat bottom is
within the area described in paragraph (i) when
the seat bottom is vertical. (See Figure 58).

(Hi) No portion of a seat or restraining barrier
located forward of the area described in para-
graph (a)(2)(i) of this section and between the
door opening and a longitudinal vertical plane
passing through the longitudinal centerline of the
bus shall extend rearwai'd of a vertical transverse
plane tangent to the foiwardmost portion of a
latch mechanism on the door. (See Figures 58
and5C.)

(3)(i) Each emergency exit door of a school
bus shall be equipped with a positive door open-

P ART 571; S 217-7

(Rev. 11/2/92)

ing device that, after the release mechanism has
been operated, under the conditions of S6, before
and after the window retention test required by
55.7—

(A) Bears the weight of the door;

(B) Keeps the door from closing past the point
at which the door is perpendicular to the side of
the bus body, regardless of the body's orienta-
tion; and

(ii) The positive door opening device shall per-
form the functions specified in paragraph (a)(3)(i)
(A) and (B) of this section without the need for
additional action beyond opening the door past
the point at which the door is perpendicular to
the side of the bus body.

(b) Emergency roof exits. After the release
mechanism has been operated, each emergency
roof exit of a school bus shall, under the condi-
tions of S6, before and after the window retention
test required by S5.1 , using the force levels speci-
fied in S5.3.3, be manually extendable by a single
person to a position that permits an opening at
least 41 centimeters high and 41 centimeters
wide. (57 FR 49413— November 2, 1992. Effec-
tive: May 2, 1994)]

S5.4.2.2 School buses less than 10,000
pounds. A school bus with a GVWR of 10,000
pounds or less shall conform to all the provisions
of S5.4.2 except that the parallelepiped dimension
for the opening of the rear emergency door or
doors shall be 45 inches high, 22 inches wide, and
6 inches deep.

S5.5 Emergency exit Identification.

S5.5.1 In buses other than school buses, except for
windows serving as emergency exits in accord-
ance with S5.2.2(b) and doors in buses with a
GVWR of 10,000 pounds or less, each emergency
door shall have the designation "Emergency
Door" or "Emergency Exit" and each push-out
window or other emergency exit shall have the
designation "Emergency Exit" followed by con-
cise operating instructions describing each motion

necessary to unlatch and open the exit, located
within 6 inches of the release mechanism.

Examples: ^

( 1 ) Lift to Unlatch Push to Open

(2) Lift Handle and Push out to Open

When a release mechanism is not located within
an occupant space of an adjacent seat, a label
meeting the requirements of S5.5.2 that indicates
the location of the nearest release mechanism
shall be placed within the occupant space.

Example: Emergency exit instructions located
next to seat ahead.

55.5.2 In buses other than school buses, except as
provided in S5.5.2.1, each marking shall be leg-
ible, when the only source of light is the normal
night-time illumination of the bus interior, to
occupants having corrected visual acuity of 20/40
(Snellen ratio) seated in the adjacent seat, seated
in the seat directly adjoining the adjacent seat, and
standing in the aisle location that is closest to that
adjacent seat. The marking shall be legible from
each of these locations when the other two cor-
responding locations are occupied.

S5.5.2.1 If the exit has no adjacent seat, the mark- w
ing must meet the legibility requirements of S5.5.2
for occupants standing in the aisle location nearest
to the emergency exit, except for a roof exit,
which must meet the legibility requirements for
occupants positioned with their backs against the
floor opposite the roof exit.

55.5.3 School Bus. Each school bus emergency
exit provided in accordance with S5.2.3.1 shall
have the designation "Emergency Door" or
"Emergency Exit," as appropriate, in letters at
least 2 inches high, of a color that contrasts with
its background, located at the top of or directly
above the emergency exit on both the inside and
outside surfaces of the bus. Concise operating
instructions describing the motions necessary to
unlatch and open the emergency exit, in letters at
least three-eighths of an inch high, of a color that

(Rev. 11/2/92)

PART 571; S 217-8

Floor Beneath Emergency Exit
View Parallel To Seat Back

Floor Beneatti Emergency Exit
View Pertendlculer To Seat Back

Figure 1 .—Low-Force Access Region for Emergency Exits Having Adjacent Seats

Floor Beneath Emeroency Exit
View Parallel To Seat Back

' Clearance area around seat back, arm rests, ar

Emergency Exit
View Perpendicular To Seat Back

Figure 2.— High-Force Access Regions for Emergency Exits Having Adjacent Seats

PART 571; S 217-9

LOW- AND HIGH-FORCE ACCESS REGIONS FOR EMERGENCY EXITS
WITHOUT ADJACENT SEATS

Figure 3A.— Side Emergency Exit

Figure 3B. — Roof Emergency Exit

PART 571; S 217-10

Inside Floor of Upright Bus

* Typical clearance around obstructions

Figure 3C.— Rear Emergency Exit Witli Rear Obstruction

Access Region
For High Forces

J— ^

I— 52 Inches

71 Inches
52 Inches

Figure 3D. — Rear Emergency Exit Without Rear Obstruction

PART 571; S 217-11

Retainer
(Design Optional)

.250 ±.025 Synthetic Underlayei
250 ±25 pal Tensile Strength
50 ±10% Elongation

NAPA Qoat Skin, Wet Chamois, or
.030±.003 Synthetic Skin
1000 ±50 psi Tensile Strength
100 ±5% Elongation

Ail Dimensions In Inches
Unless Otherwise Specified

Figure 4

PART 571; S 217-12

Front

Sides of Bus Body

Side Emergency
Exit Door *<xw

^ s-^ .s ^i

30 cm
Minimum

Centeriine of Bus

Figure 5A

PART 571: S 217-13

Figure 5B

Figure 5C

PART 571; S 217-14

Table 1. Minimum Specific Intensity Per Unit Area (SIA)

(Candelas per Footcandle Per Square Foot)

Type 111 Retroreflective Material

A — Glass Bead Retroreflective Element Material

Observation Angle (°)

Entrance Angle (°)

White

Red

Yellow

0.2

-4

250

170

0.2

+30

150

100

0.5

-4

0.5

+30

B— Prismatic Retroreflective Element Material

Observation Angle (°)

Entrance Angle (°)

White

Red

Yellow

0.2

-4

250

170

0.2

+30

13.3

0.5

-4

200

136

0.5

+30

contrasts with its background, shall be located
within 6 inches of the release mechanism on the
inside surface of the bus.
Example:

(1) Lift to Unlatch

Push to Open

(2) Lift Handle

Push Out to Open.

S5.5.3 School Bus.

(a) Each school hiis emergency exit provided in
accordance with S5.2.3.1 shall have the designa-
tion "Emergency Door" or "Emergency Exit,"
as appropriate, in letters at least 5 centimeters
high, of a color that contrasts with its hack-
ground. For emergency exit doors, the designa-
tion shall be located at the top of, or directly
above, the emergency exit door on both the inside
and outside surfaces of the bus. The designation
for roof exits shall be located on an inside sur-
face of the exit, or within 30 centimeters of the
roof e.xit opening. For emergency window exits,
the designation shall be located at the top of, or
directly above, or at the bottom of the emergency
window exit on both the inside and outside sur-
faces of the bus.

(b) Concise operating instructions describing
the motions necessary to unlatch and open the
emergency e.xit shall be located within J5 centi-
meters of the release mechanism on the inside
surface of the bus. These instructions shall be in

letters at least 1 centimeter high and of a color
that contrasts with its background
Example:

(J) Lift to Unlatch, Push to Open
(2) Turn Handle, Push Out to Open
(c) Each opening for a required emergency exit
shall be outlined around its outside perimeter
with a minimum 3 centimeters wide retroreflective
tape, either red, white, or yellow in color, that,
when tested under the conditions specified in S6.1
of 571.131, meets the criteria specified in Table
1. (57 F.R. 49413— November 2, 1992. Effec-
tive: May 2, 1994)]

S6. Test conditions.

56.1 The vehicle is on a flat, horizontal surface.

56.2 The inside of the vehicle and the outside
environment are kept at any temperature from 70°
to 85° Fahrenheit for 4 hours immediately preced-
ing the tests and during the tests.

56.3 For the window retention test, windows are
installed, closed, and latched (where latches are
provided) in the condition intended for normal bus
operation.

56.4 For the emergency exit release and extension
tests, windows are installed as in S6.3, seats, arm-
rests, and interior objects near the windows are
installed as for normal use, and seats are in the
upright position. ^^ p ^ g^g^

May 10, 1972

PART 571: S 217-15

PREAMBLE TO AN AMENDMENT TO PART 572
Anthropomorphic Test Dummies
(Docket and RIN Numbers Not Issued)

ACTION: Final rule; technical amendment.

SUMMARY: This rule corrects the erroneous dates
shown in the Code of Federal Regulations for the
Anthropomorphic Test Dummy Parts List and the
Parts List Index for the Hybrid III test dummy.

EFFECTIVE DATE: October 14, 1992.

SUPPLEMENTARY INFORMATION: 49 CFR Part
572, Anthropomorphic Test Dummies, specifies
the dimensions, physical attributes, and perform-
ance characteristics of the Hybrid III test dummy
in Subpart E. A general description of the Hybrid
III test dummy is set forth m 572.31(a), which ref-
erences six items that comprise the drawing and
specifications package for the test dummy. The
first of these six items is set forth in 572.31(a)(1)
as follows:

The Anthropomorphic Test Dummy Parts List,
dated December 15, 1987, and containing 13
pages, and a Parts List Index, dated December
15, 1987, containing 8 pages.
The Dummy Parts List and the Parts List Index
were approved for incorporation by reference by
the Director of the Federal Register. As a part of
that approval, the Dummy Parts List and the Parts
List Index are on file in the reference library of
the office of the Federal Register and in the gen-
eral reference section of the NHTSA Docket Sec-
tion. However, the Dummy Parts List and the
Parts List Index that are on file are both dated
March 10, 1988. These March 10, 1988 lists are

the correct version and the Parts List Index that
the agency intended to incorporate into 49 CFR
Part 572. Accordingly, this rule amends 572.31(a)
so that it refers to the Dummy Parts List and
Parts List Index of March 10, 1988.

This correction imposes no duties or respon-
sibilities on any party, nor does it alter any exist-
ing obligations. Instead, it simply ensures that the
public will have an accurate copy of Part 572 in
Title 49 of the Code of Federal Regulations.
Accordingly, NHTSA finds for good cause that
notice and opportunity for comment on this
correction are unnecessary, and this correction is
effective upon publication in the Federal Register.

In consideration of the foregoing, 49 CFR
§ 572.31(a)(1) amended as follows: Section
572.31 is amended by revising paragraph (a)(1) to
read as follows: 572.31 General description.

(a)

(1) The Anthropomorphic Test Dummy Part
List, dated March 10, 1988, and containing 13
pages, and a Parts List Index, dated March 10,
1988, containing 8 pages.

*****

Issued on October 7, 1992.

Marion C. Blakey
Administrator

57 F.R. 47009
October 14, 1992

PART 572— PRE- 1 03

PART 572— ANTHROPOMORPHIC TEST DUMMIES

Subpart A— General

§572.1 Scope. This part describes the
anthropomorphic test dummies that are to be used
for comphance testing of motor vehicles and
motor vehicle equipment with motor vehicle
safety standards.

§572.2 Purpose. The design and performance
headings: criteria specified in this part are
intended to describe measuring tools with suffi-
cient precision to give repetitive and correlative
results under similar test conditions and to reflect
adequately the protective performance of a vehicle
or item, of motor vehicle equipment, with respect
to human occupants.

§572.3 Application. This part does not in itself
impose duties or liabilities on any person. It is a
description of tools that measure the performance
of occupant protection systems required by the
safety standards that incorporate it. It is designed
to be referenced by, and become a part of, the test
procedures specified in motor vehicle safety stand-
ards such as Standard No. 208, Occupant Crash
Protection.

§572.4 Terminology.

(a) The tenn "dummy," when used in this
Subpart A, refers to any test device described by
this part. The term "dummy," when used in any
other subpart of this part, refers to the particular
dummy described in that part.

(b) Terms describing parts of the dummy, such
as "head," are the same as names for cor-
responding parts of the human body.

(c) The term "unimodal," when used in
[Subpart C and I], refers to an acceleration-time
curve which has only one prominent peak. (56

F.R. 57830 November 14, 1991. Effective: May

12, 1992)

Subpart B— 50th Percentile Male

§572.5 General description.

(a) The dummy consists of the component
assemblies specified in Figure 1, which are

described in their entirety by means of approxi-
mately 250 drawings and specifications that are
grouped by component assemblies under the fol-
lowing nine headings:

SA 150 M070
SA 150M071
SA 150 M050
SA 150 M060

SA 150 M080
SA 150M081
SA 150 MOlO
SA 150 M020
SA 150 M030

Right arm assembly
Left arm assembly
Lumbar spine assembly
Pelvis and abdomen
assembly

Right leg assembly
Left leg assembly
Head assembly
Neck assembly
Shoulder-thorax assembly

(b) The drawings and specifications referred to
in fros regulation that are not set forth in full are
hereby incorporated in this part by reference.
These materials are thereby made part of this
regulation. The Director of the Federal Register
has approved the materials incorporated by ref-
erence. For materials subject to change, only the
specific version approved by the Director of the
Federal Register and specified in the regulation
are incorporated. A notice of any change will be
published in the Federal Register.

(c) The materials incorporated by reference are
available for exatnination in Docket 73-08,
Docket Section, National Highway Traffic Safety
Administration, Room 5109, 400 Seventh Street
S.W., Washington, D.C. 20590. Copies may be
obtained from Rowley-Scher Reprographics, Inc.,
1216 K Street N.W., Washington, D.C. 20005
(202) 628-6667. The drawings and specifications
are also on file in the reference library of the
Office of the Federal Register, National Archives
and Records Administration, Washington, D.C.

(d) Adjacent segments are joined in a manner
such that throughout the range of motion and also
under crash-impact conditions there is no contact
between metallic elements except for contacts that
exist under static conditions.

(e) The structural properties of the dummy are
such that the dummy conforms to this part in

(Rev. 11/14/91)

every respect both before and after being used in
vehicle tests specified in Standard No. 208
(§571.208).

(f) A specimen of the dummy is available for
surface measurements, and access can be arranged
through: Office of Vehicle Safety Standards,
National Highway Traffic Safety Administration,
400 Seventh Street, S.W., Washington, D.C.
20590.

§572.6 Head.

(a) The head consists of the assembly shown as
number SA 150 MO 10 in Figure 1 and conforms
to each of the drawings subtended by number SA
150 MOIO.

(b) When the head is dropped from a height of
10 inches in accordance with paragraph (c) of this
section, the peak resultant accelerations at the
location of the accelerometers mounted in the
head form in accordance with §572.1 1(b) shall be
not less than 210g. and not more than 260g. The
acceleration/time curve for the test shall be
unimodal and shall lie at or above the lOOg level
for an interval not less than 0.9 milliseconds and
not more than 1.5 milliseconds. The lateral accel-
eration vector shall not exceed lOg.

(1) Suspend the head as shown in Figure 2,
so that the lowest point on the forehead is 0.5
inches below the lowest point on the dummy's
nose when the midsagittal plane is vertical.

(2) Drop the head from the specified height
by a means that ensures instant release onto a
rigidly supported flat horizontal steel plate, 2
inches thick and 2 feet square, which has a
clean, dry surface and any microfinish of not
less than 8 microinches (rms) and not more
than 80 microinches (rms).

(3) Allow a time period of at least 2 hours
between successive tests on the same head.

§572.7 Neck.

(a) The neck consists of the assembly shown as
number SA 150 M020 in Figure 1 and conforms
to each of the drawings subtended by number SA
150 M020.

(b) When the neck is tested with the head in
accordance with paragraph (c) of this section, the
head shall rotate in reference to the pendulum's
longitudinal centerline a total of 68° ± 5° about
its center of gravity, rotating to the extent speci-

fied in the following table at each indicated point
in time, measured from impact, with a chordal
displacement measured at its center of gravity that
is within the limits specified. The chordal
displacement at time T is defined as the straight
line distance between (1) the position relative to
the pendulum arm of the head center of gravity
at time zero, and (2) the position relative to the
pendulum arm of the head center of gravity at
time T as illustrated by Figure 3. The peak result-
ant acceleration recorded at the location of the
accelerometers mounted in the head form in
accordance with §572. 11(b) shall not exceed 26g.
The pendulum shall not reverse direction until the
head's center of gravity returns to the original
zero time position relative to the pendulum arm.

Rotation (degrees)

Time (ms) ±
(2 + ,08T)

Chordal
Displacement
(inches ±0.5)

0.0

2.6

4.8

Maximum

5.5

4.8

2.6

112

0.0

(1) Mount the head and neck on a rigid pen-
dulum as specified in Figure 4, so that the
head's midsagittal plane is vertical and
coincides with the plane of motion of the pen-
dulum's longitudinal centerline. Mount the neck
directly to the pendulum as shown in Figure 4.

(2) Release the pendulum and allow it to fall
freely from a height such that the velocity at
impact is 23.5 ± 2.0 feet per second (fps),
measured at the center of the accelerometer
specified in Figure 4.

(3) Decelerate the pendulum to a stop with
an acceleration-time pulse described as follows:

(i) Establish 5g and 20g levels on the a — t
curve.

(ii) Establish t| at the point where the ris-
ing a — t curve first crosses the 5g level, ij
at the point where the rising a — t curve first
crosses the 20g level, ts at the point where
the decaying a — t curve last crosses the 20g
level, and t4 at the point where the decaying
a — t curve first crosses the 5g level.

(iii) t2-ti shall be not more than 3 milli-
seconds.

(iv) t3-t2 shall be not less than 25 milli-
seconds and not more than 30 milliseconds.

PART 572-2

(v) t4 — 13 shall be not more than 10 milli-
seconds.

(vi) The average deceleration between t2
and t3 shall be not less than 20g and not
more than 24g.

(4) Allow the neck to flex without impact of
the head or neck with any object other than the
pendulum arm.

§572.8 Thorax.

(a) The thorax consists of the assembly shown
as number SA 150 M030 in Figure 1, and con-
forms to each of the drawings subtended by num-
ber SA 150 M030.

(b) The thorax contains enough unobstructed
interior space behind the rib cage to permit the
midpoint of the sternum to be depressed 2 inches
without contact between the rib cage and other
parts of the dummy or its instrumentation, except
for instruments specified in subparagraph (d)(7)
of this section.

(c) When impacted by a test probe conforming
to §572.1 1(a) at 14 fps and at 22 fps in accord-
ance with paragraph (d) of this section, the thorax
shall resist with forces measured by the test probe
of not more than 1450 pounds and 2250 pounds,
respectively, and shall deflect by amounts not
greater than 1.1 inches and 1.7 inches, respec-
tively. The internal hysteresis in each impact shall
not be less than 50 percent and not more than 70
percent.

(d) Test Procedure:

(1) With the dummy seated without back
support on a surface as specified in §572.11(1)
and in the orientation specified in §572.11(1),
adjust the dummy arms and legs until they are
extended horizontally forward parallel to the
midsagittal plane.

(2) Place the longitudinal center line of the
test probe so that it is 17.7 ± 0.1 inches above
the seating surface at impact.

(3) Align the test probe specified in §572.11
(a) so that at impact its longitudinal centerline
coincides within 2 degrees of a horizontal line
in the dummy's midsagittal plane.

(4) Adjust the dummy so that the surface
area on the thorax immediately adjacent to the
projected longitudinal center line of the test
probe is vertical. Limb support, as needed to
achieve and maintain this orientation, may be
provided by placement of a steel rod of any

diameter not less than one-quarter of an inch
and not more than three-eighths of an inch,
with hemispherical ends, vertically under the
limb at its projected geometric center.

(5) Impact the thorax with the test probe so
that its longitudinal centerline falls within 2
degrees of a horizontal line in the dummy's
midsagittal plane at the moment of impact.

(6) Guide the probe during impact so that it
moves with no significant lateral, vertical, or
rotational movement.

(7) Measure the horizontal deflection of the
sternum relative to the thoracic spine along the
line established by the longitudinal centerline
of the probe at the moment of impact, using a
potentiometer mounted inside the sternum.

(8) Measure hysteresis by determining the
ratio of the area between the loading and
unloading portions of the force deflection curve
to the area under the loading portion of the
curve.

§572.9 Lumbar spine, abdomen, and pelvis.

(a) The lumbar spine, abdomen, and pelvis con-
sist of the assemblies designated as numbers SA
150 M050 and SA 150 M060 in Figure 1 and
conform to the drawings subtended by these num-
bers.

(b) When subjected to continuously applied
force in accordance with paragraph (c) of this sec-
tion, the lumbar spine assembly shall flex by an
amount that permits the rigid thoracic spine to
rotate from its initial position in accordance with
Figure 1 1 by the number of degrees shown below
at each specified force level, and straighten upon
removal of the force to within 12 degrees of its
initial position in accordance with Figure 1 1 .

Flexion (degrees)

Force
(±6 pounds)

28
40
52

(1) Assemble the thorax, lumbar spine, pel-
vic, and upper leg assemblies (above the femur
force transducers), ensuring that all component
surfaces are clean, dry, and untreated unless
otherwise specified, and attach them to the
horizontal fixture shown in Figure 5 at the two

PART 572-3

link rod pins and with the mounting brackets
for the lumbar test fixtures illustrated in Figure
6 to 9.

(2) Attach the rear mounting of the pelvis to
the pelvic instrument cavity rear face at the
four V/' cap screw holes and attach the front
mounting at the femur axial rotation joint.
Tighten the mountings so that the pelvic-lum-
bar adapter is horizontal and adjust the femur
friction plungers at each hip socket joint to 240
inch-pounds torque.

(3) Flex the thorax forward 50° and the rear-
ward as necessary to return it to its initial posi-
tion in accordance with Figure 1 1 unsupported
by external means.

(4) Apply a forward force perpendicular to
the thorax instrument cavity rear face in the
midsagittal plane 15 inches above the top sur-
face of the pelvic-lumbar adapter. Apply the
force at any torso deflection rate between .5
and 1 .5 degrees per second up to 40° of flexion
but no further, continue to apply for 10 seconds
that force necessary to maintain 40° of flexion,
and record the force with an instrument
mounted to the thorax as shown in Figure 5.
Release all force as rapidly as possible and
measure the return angle 3 minutes after the
release.

(d) When the abdomen is subjected to continu-
ously applied force in accordance with paragraph
(e) of this section, the abdominal forcedeflection
curve shall be within the two curves plotted in
Figure 10.

(e) Test procedure:

(1) Place the assembled thorax, lumbar spine,
and pelvic assemblies in a supine position on
a fiat rigid, smooth, dry, clean horizontal sur-
face, ensuring that all component surfaces are
clean, dry, and untreated unless otherwise
specified.

(2) Place a rigid cylinder 6 inches in diame-
ter and 18 inches long transversely across the
abdomen, so that the cylinder is symmetrical
about the midsagittal plane, with its longitu-
dinal centerline horizontal and perpendicular to
the midsagittal plane at a point 9.2 inches
above the bottom line of the buttocks, meas-
ured with the dummy positioned in accordance
with Figure 1 1 .

(3) Establish the zero deflection point as the
point at which a force of 10 pounds has been
reached. ^

(4) Apply a vertical downward force through ^
the cylinder at any rate between 0.25 and 0.35
inches per second.

(5) Guide the cylinder so that it moves with-
out significant lateral or rotational movement.

§572.10 Limbs.

(a) The limbs consist of the assemblies shown
as numbers SA 150 M070, SA 150 M071, SA
150 M080, and SA 150 M081 in Figure 1 and
conform to the drawings subtended by these num-
bers.

(b) When each knee is impacted at 6.9 ft/ sec.
in accordance with paragraph (c) of this section,
the maximum force on the femur shall be not
more than 2500 pounds and not less than 1850
pounds, with a duration above 1000 pounds of not
less than 1.7 milliseconds.

(1) Seat the dummy without back support on
a surface as specified in §572.11(1) that is 17.3

± 0.2 inches above a horizontal surface, ori- ^
ented as specified in §572.11(1), and with the ^
hip joint adjustment at any setting between Ig
and 2g. Place the dummy legs in planes parallel
to its midsagittal plane (knee pivot centerline
perpendicular to the midsagittal plane) and with
the feet flat on the horizontal surface. Adjust
the feet and lower legs until the lines between
the midpoints of the knee pivots and the ankle
pivots are at any angle not less than 2 degrees
and not more than 4 degrees rear of the verti-
cal, measured at the centerline of the knee piv-
ots.

(2) Reposition the dummy if necessary so
that the rearmost point of the lower legs at the
level one inch below the seating surface
remains at any distance not less than 5 inches
and not more than 6 inches forward of the for-
ward edge of the seat.

(3) Align the test probe specified in
§S72.11(a) so that at impact its longitudinal
centerline coincides within 20 with the longitu-
dinal centerline of the femur.

(4) Impact the knee with the test probe mov-
ing horizontally and parallel to the midsagittal \^
plane at the specified velocity.

PART 572^

(5) Guide the probe during impact so that it
moves with no significant lateral, vertical, or
rotational movement.

§572.11 Test conditions and instrumentation.

(a) The test probe used for thoracic and knee
impact tests is a cylinder 6 inches in diameter that
weighs 51.5 pounds including instrumentation. Its
impacting end has a flat right face that is rigid
and that has an edge radius of 0.5 inches.

(b) Accelerometers are mounted in the head on
the horizontal transverse bulkhead shown in the
drawings subreferenced under assembly No. SA
150 MO 10 in Figure 1, so that their sensitive axes
intersect at a point in the midsagittal plane 0.5
inches above the horizontal bulkhead and 1.9
inches ventral of the vertical mating surface of
the skull with the skull cover. One accelerometer
is aligned with its sensitive axis perpendicular to
the horizonal bulkhead in the midsagittal plane
and with its seismic mass center at any distance
up to 0.3 inches superior to the axial intersection
point. Another accelerometer is aligned with its
sensitive axis parallel to the horizontal bulkhead
and perpendicular to the midsagittal plane, and
with its seismic mass center at any distance up to
1.3 inches to the left of the axial intersection
point (left side of dummy is the same as that of
man). A third accelerometer is aligned with its
sensitive axis parallel to the horizontal bulkhead
in the midsagittal plane, and with its seismic mass
center at any distance up to 1.3 inches dorsal to
the axial intersection point.

(c) Accelerometers are mounted in the thorax
by means of a bracket attached to the rear vertical
surface (hereafter "attachment surface") of the
thoracic spine so that their sensitive axes intersect
at a point in the midsagittal plane 0.8 inches
below the upper surface of the plate to which the
neck mounting bracket is attached and 3.2 inches
perpendicularly forward of the surface to which
the accelerometer bracket is attached. One accel-
erometer has its sensitive axis oriented parallel to
the attachment surface in the midsagittal plane,
with its seismic mass center at any distance up to
1.3 inches inferior to the intersection of the sen-
sitive axes specified above. Another accelerometer
has its sensitive axis oriented parallel to the
attachment surface and perpendicular to the
midsagittal plane, with its seismic mass center at
any distance up to 0.2 inches to the right of the

intersection of the sensitive axes specified above.
A third accelerometer has its sensitive axis ori-
ented perpendicular to the attachment surface in
the midsagittal plane, with its seismic mass center
at any distance up to 1.3 inches dorsal to the
intersection of the sensitive axes specified above.
Accelerometers are oriented with the dummy in
the position specified in §572.11(1).

(d) A force-sensing device is mounted axially
in each femur shaft so that the transverse center-
line of the sensing element is 4.25 inches from
the knee's center of rotation.

(e) The outputs of acceleration and
forcesensing devices installed in the dummy and
in the test apparatus specified by this Part are
recorded in individual data channels that conform
to the requirements of SAE Recommended Prac-
tice J211a, December 1971, with channel classes
as follows:

(1) Head acceleration— Class 1000.

(2) Pendulum acceleration — Class 60.

(3) Thorax acceleration — Class 180.

(4) Thorax compression — Class 180.

(5) Femur force— Class 600.

(f) The mountings for sensing devices have no
resonance frequency within a range of 3 times the
frequency range of the applicable channel class.

(g) Limb joints are set at Ig, barely restraining
the weight of the limb when it is extended hori-
zontally. The force required to move a limb seg-
ment does not exceed 2g throughout the range of
limb motion.

(h) Performance tests are conducted at any
temperature from 66° F to 78° F and at any rel-
ative humidity from 10 percent to 70 percent after
exposure of the dummy to these conditions for a
period of not less than 4 hours.

(i) For the performances tests specified in
§§572.8, 572.9, and 572.10, the dummy is posi-
tioned in accordance with Figure 1 1 as follows:
(1) The dummy is placed on a flat, rigid,
smooth, clean, dry, horizontal, steel test surface
whose length and width dimensions are not less
than 16 inches, so that the dummy's midsagittal
plane is vertical and centered on the test sur-
face and the rearmost points on its lower legs
at the level of the test surface are at any dis-
tance not less than 5 inches and not more than
6 inches forward of the forward edge of the test
surface.

(2) The pelvis is adjusted so that the upper
surface of the lumbar-pelvic adapter is hori-
zontal.

(3) The shoulder yokes are adjusted so that
they are at the midpoint of their anterior pos-
terior travel with their upper surfaces hori-
zontal.

(4) The dummy is adjusted so that the rear
surfaces of the shoulders and buttocks are tan-
gent to a transverse vertical plane.

(5) The upper legs are positioned symmetri-
cally about the midsagittal plane so that the
distance between the knee pivot bolt heads is
11.6 inches.

(6) The lower legs are positioned in planes
parallel to the midsagittal plane so that the
lines between the midpoint of the knee pivots
and the ankle pivots are vertical.

(j) The dummy's dimensions, as specified in
drawing number SA 150 M002, are determined as
follows:

(1) With the dummy seated as specified in
paragraph (i), the head is adjusted and secured
so that its occiput is 1.7 inches forward of the
transverse vertical plane with the vertical mat-
ing surface of the skull with its cover parallel
to the transverse vertical plane.

(2) The thorax is adjusted and secured so
that the rear surface of the chest accelerometer
mounting cavity is inclined 30 forward of verti-
cal.

(3) Chest and waist circumference and chest
depth measurements are taken with the dummy
positioned in accordance with paragraph (i) (1)
and (2) of this section.

(4) The chest skin and abdominal sac are
removed and all following measurements are
made without them.

(5) Seated height is measured from the seat-
ing surface to the uppermost point on the head-
skin surface.

(6) Shoulder pivot height is measured from
the seating surface to the center of the arm ele-
vation pivot.

(7) H-point locations are measured from the
seating surface to the center of the holes in the
pelvis flesh covering in line with the hip
motion ball.

(8) Knee pivot distance from the backline is
measured to the center of the knee pivot bolt
head.

(9) Knee pivot distance from floor is meas-
ured from the center of the knee pivot bolt
head to the bottom of the heel when the foot
is horizontal and pointing forward.

(10) Shoulder width measurement is taken at
arm elevation pivot center height with the
centerlines between the elbow pivots and the
shoulder pivots vertical.

(11) Hip width measurement is taken at
widest point of pelvic section.

(k) Performance tests of the same component,
segment, assembly, or fully assembled dummy are
separated in time by a period of not less than 30
minutes unless otherwise noted.

(1) Surfaces of dummy components are not

painted except as specified in this part or in

drawings subtended by this part.

PART 572-6

Arm Assembly
SA 150 M070 Right
SA 150 M071 Left

Shoulder-Ttiorax
Assembly
SA 150 M030

Leg Assembly
SA 150 M080 Right
SA 150 M081 Left

Figure 2.— Head Positioning For Drop Tests

Connecting Ring

Steel Blocl^
2"x24"x24"

HEAD POSITIONING FOR DROP TESTS

Figure 2.

Pendulum
Pivot Point

Head Rotation

Chordal
Displacement

Figure 3.— Neck Component Test

PART 572- Subpart B-ART PAGE 1

Inertial Properties of Pendulum
Without Test Specimen.
Weigtit 65.2 lbs.

Moment of Inertia 24.5 lb. ft. Sec
About Pivot Axis

CG of Pendulu
Apparatus Without
Test Specimen

Accelerometer

V,e" Structural
Steel Tube

Alummum Honeycomb
(Hexcell 1.8 Ibs./cu. ft.)
Ref.

• 3" X 6" X ^/e" Plate (Sharp Edges)
% " '^ CG of Test Specimen

PART 572-Subpart B-ART PAGE 2

Line of Force Application

Figure 9.

Attachment 10-32 Screws

(Four Places)

Figure

Link Rod (Items F/04 and G/04
Drawing Number SA 150 M002 Sheet 1.)
Attachment to Bedplate
With '/,-24 Bolts

^l,.^

1 1 1 1

2- ¥4

)-■

1 Ml

V Vl 1

2-V.

1 r

_k_,__i.^

i '■- '

— *1 |-^'/aV\

'/, Wide Slot

(Two Places) t* ^■'^'-

W"^

i 2-V.

Vl Sq. Steel Stock 7- '/a Long
Welded to Angle

6x6 Structural Steel Angle

PART 572-Subpart B-ART PAGE

'r-'i "-<

- t

I-'/,. ±

1 1 r'^'

1 1 1

V V '

1 1 1

-U-

3-'V,

-^i-y. -—

V '/j; Drill Thru
4 Places

/T/I

2.0

■^ V„-24 Tap Thru (2 Holes)

Tolerance ± '/,/'
Material: Steel
Welded Construction

»;„ Drill Ttin
'/8-24 Tap Thru Top Plate / 2 Places
and Top of Tubing

24 1

^15.V,-J

'/„ Drill Hole <t

PART 572-Subpart B-ART PAGE 4

M1_L

.25

Ttr|".25

Construction: Aluminum or Steel Weldment
Tolerance: ± .03 Two Places

± .005 Three Places

3.000
■ 3.50 •

.-.^

I 1 -^^ °'^

Clear Drill For
10-32 Screw
4 Places

.25R (4 Places)

..^— 73

—

50
40
30
20

1 1

1
1

0.25

0.50 0.75

1.00

1.30

DISPLACEMENT (Inches)

PART 572-Subpart B-ART PAGE 5

Spacer (Ref.)

3° (Ref.)

Vertical Mating Surface of Skull
Parallel to ttie Vertical Backline

Tangent

Arm

Elevation

Pivot

Shoulder Yoke Upper Surface
Horizontal and Centered at
Mid-Travel in Anterior-Pos-
Terlor Director.

Lumbar— Pelvic Adaptor
Upper Surface Horizontal

PART 572-Subpart B-ART PAGE 6

Space for figures 12 thru 14
reserved for future use.

PART 572-Subpart B-ART PAGE 7

Subpart C— Three Year Old Child

§572.15 General description.

(a) The dummy consists of the component
assembhes specified in drawing SA 103C 001,
which are described in their entirety by means of
approximately 122 drawings and specifications
and an Operation and Maintenance Manual, dated
May 28, 1976. The drawings and specifications
are grouped by component assemblies under the
following thirteen headings:

SA 103C 010 Head Assembly

SA 103C 020 Neck Assembly

SA 103C 030 Torso Assembly

SA 103C 041 Upper Ann Assembly Left

SA 103C 042 Upper Ann Assembly Right

SA 103C 051 Foreami Hand Assembly Left

SA 103C 052 Foreami Hand Assembly

Right

SA 103C 061 Upper Leg Assembly Left

SA 103C 062 Upper Leg Assembly Right

SA 103C 071 Lower Leg Assembly Left

SA 103C 072 Lower Leg Assembly Right

SA 103C 081 Foot Assembly Left

SA 103C 082 Foot Assembly Right

(b) The drawings, specifications, and operation
and maintenance manual referred to in this regu-
lation that are not set forth in full are hearby
incorporated in this Part by reference. These
materials are thereby made part of this regulation.
The Director of the Federal Register has approved
the materials incorporated by reference. For mate-
rials subject to change, only the specific version
approved by the Director of the Federal Register
and specified in the regulation are incorporated. A
notice of any change will be published in the
Federal Register. As a convenience to the reader
the materials incorporated by reference are listed
in the Finding Aid Table found at the end of this
volume of the Code of Federal Regulations.

(c) The materials incorporated by reference are
available for examination in Docket 78-09. Room
5109, Docket Section, National Highway Traffic
Safety Administration, 400 Seventh Street S.W.,
Washington, D.C. 20590. Copies may be obtained
from Rowley-Scher Reprographics, Inc., 1216 K
Street, N.W., Washington, D.C. 20005, ((202)
628-6667). The materials are also on file in the
reference library of the Federal Register, National
Archives and Records Administration, Washing-
ton, D.C.

(d) Adjacent segments are joined in a manner
such that throughout the range of motion and also
under simulated crash-impact conditions, there is
no contact between metallic elements except for
contacts that exist under static conditions.

(e) The structural properties of the dummy are
such that the dummy conforms to this part in
every respect both before and after being used in
vehicle tests specified by Standard No. 213 of this
chapter (§571.213).

(f) The patterns of all cast and molded parts for
reproduction of the molds needed in manufactur-
ing of the dummies can be obtained on a loan
basis by manufacturers of the test dummies, or
others if need is shown, from the Office of
Vehicle Safety Standards, NHTSA, 400 Seventh
Street S.W., Washington, D.C. 20590.

§572.16 Head.

(a) [The head consists of the assembly des-
ignated as SA 103C 010 on drawing no. SA 103C
001, and conforms to either —

(1) each item specified on drawing SA 103C
002(B), sheet 8; or

(2) each item specified on drawing SA 103C
002, sheet 8.

(b) When the head is impacted by a test probe
specified in §572.2 1(a)(1) at 7 fps., then the peak
resultant acceleration measured at the location of
the accelerometer mounted in the headform in
according to §572.2 1(b) is not less than 95g, and
not more than 118g.

(1) The recorded acceleration-time curve for
this test is unimodal at or above the 50g level,
and lies at or above that level for intervals:

(i) in the case of the head assembly speci-
fied in paragraph (a)(1) of this section, not
less than 1.3 milliseconds and not more than
2.0 milliseconds;

(ii) in the case of the head assembly speci-
fied in paragraph (a)(2) of this section, not
less than 2.0 milliseconds and not more than
3.0 milliseconds.

(2) The lateral acceleration vector shall not
exceed 7g. (55 F.R. 30465— July 26, 1990. Effec-
tive: August 27, 1990)]

(1) Seat the dummy on a seating surface
having a back support as specified in
§ 572.21(h) and orient the dummy in accord-
ance with § 572.21(h) and adjust the joints of

(Rev. 7/26/90)

the limbs at any setting between Ig and 2g,
which just supports the limbs" weight when the
limbs are extended horizontally forward.

(2) Adjust the test probe so that its longitu-
dinal centerline is at the forehead at the point
of orthogonal intersection of the head
midsagittal plane and the transverse plane
which is perpendicular to the "Z" axis of the
head (longitudinal centerline of the skull
anchor) and is located 0.6 ± .1 inches above the
centers of the head center of gravity reference
pins and coincides within 2 degrees with the
line made by the intersection of horizontal and
midsagittal planes passing through this point.

(3) Adjust the dummy so that the surface
area on the forehead immediately adjacent to
the projected longitudinal centerline of the test
probe is vertical.

(4) Impact the head with the test probe so
that at the moment of impact the probe's
longitudinal centerline falls within 2 degrees of
a horizontal line in the dummy's midsagittal
plane.

(5) Guide the probe during impact so that it
moves with no significant lateral, vertical, or
rotational movement.

(6) Allow a time period of at least 20 min-
utes between successive tests of the head.

§572.17 Neck.

[(a)(1) The neck for use with the head assem-
bly described in § 572.16(a)(1) consists of the
assembly designated as SA 103C 020 on drawing
No. SA 103C 001, and conforms to each item
specified on drawing No. SA 103C 002(B), sheet
9.

(2) The neck for use with the head assembly
described in § 572.16(a)(2) consists of the
assembly designated as SA 103C 020 on draw-
ing No. SA 103C 001, and confomis to each
item specified on drawing No. SA 103C 002,
sheet 9. (55 F.R. 30465— .luly 26, 1990. Effec-
tive: August 27, 1990)]

(degrees)

Time (ms)
±(2 + .08T)

Chordal
Displacemei
(inches ±0.f

Maximum

(Rev. 7/26/90)

2.2

4.3

5.8

4.3

108

2.2

123

PART 572-

(b) When the head-neck assembly is tested in
accordance with paragraph (c) of this section, the
head shall rotate in reference to the pendulum's
longitudinal centerline a total of 84 degrees ± 8
degrees about its center of gravity, rotating to the
extent specified in the following table at each
indicated point in time, measured from impact,
with the chordal displacement measured at its
center of gravity. The chordal displacement at
time T is defined as the straight line distance
between (1) the position relative to the pendulum
arm of the head center of gravity at time zero,
and (2) the position relative to the pendulum arm
of the head center of gravity at time T as illus-
trated by Figure 3. The peak resultant acceleration
recorded at the location of the accelerometers
mounted in the headform in accordance with
§ 572.21(b) shall not exceed 30g. The pendulum
shall not reverse direction until the head's center
of gravity returns to the original zero time posi-
tion relative to the pendulum arm.

(2) Release the pendulum and allow it to fall
freely from a height such that the velocity at
impact is 17.00 ± 1.0 feet per second (fps),
measured at the center of the accelerometer
specified in Figure 4.

(3) Decelerate the pendulum to a stop with
an acceleration-time pulse described as follows:

(i) Establish 5g and 20g levels on the a-t
curve.

(ii) Establish t| at the point where the a-t
curve first crosses the 5g level, t2 at the
point where the rising a-t curve first
crosses the 20g level, U at the point where
the decaying a — t curve last crosses the 20g
level, and U at the point where the decaying
a-t curve first crosses the 5g level.

(iii) t2 — ti, shall be not more than 4 milli-
seconds.

(iv) t3-t2, shall be not less than 18 and
not more than 21 milliseconds.

(v) t4-t3, shall be not more than 5 milli-
seconds.

(vi) The average deceleration between t^
and t3 shall be not less than 20g and not
more than 34g.

(4) Allow the neck to flex without contact of
the head or neck with any object other than the
pendulum arm.

(5) Allow a time period of at least 1 hour
between successive tests of the head and neck.

§572.18 Thorax.

(a) The thorax consists of the part of the torso
shown in assembly drawing SA 103C 001 by
number SA 103C 030 and conforms to each of
the applicable drawings listed under this number
on drawings SA 103C 002, sheets 10 and 11.

(b) When impacted by a test probe conforming
to § 572.21(a) at 13 fps. in accordance with para-
graph (c) of this section, the peak resultant accel-
erations at the location of the accelerometers
mounted in the chest cavity in accordance with
§572.2 1(c) shall be not less than 50g and not
more than 70g. The acceleration-time curve for
the test shall be unimodal at or above the 30g
level and shall lie at or above the 30g level for
an interval not less than 2.5 milliseconds and not
more than 4.0 milliseconds. The lateral accelera-
tion shall not exceed 5g.

(1) With the dummy seated without back
support on a surface as specified in § 572.21(h)
and oriented as specified in § 572.21(h), adjust
the dummy arms and legs until they are
extended horizontally forward parallel to the
midsagittal plane, the joints of the limbs are
adjusted at any setting between Ig and 2g,
which just supports the limbs' weight when the
limbs are extended horizontally forward.

(2) Establish the impact point at the chest
midsagittal plane so that it is 1.5 inches below
the longitudinal centerline of the bolt that
attaches the top of the ribcage sternum to the
thoracic spine box.

(3) Adjust the dummy so that the tangent
plane at the surface on the thorax immediately
adjacent to the designated impact point is verti-
cal and parallel to the face of the test probe.

(4) Place the longitudinal centerline of the
test probe to coincide with the designated
impact point and align the test probe so that at
impact its longitudinal centerline coincides
within 2 degrees with the line formed by inter-

section of the horizontal and midsagittal planes
passing through the designated impact point.

(5) Impact the thorax with the test probe so
that at the moment of impact the probe's
longitudinal centerline falls within 2 degrees of
a horizontal line in the dummy midsagittal
plane.

(6) Guide the probe during impact so that it
moves with no significant lateral, vertical or
rotational movement.

(7) Allow a time period of at least 20 min-
utes between successive tests of the chest.

§572.19 Lumbar spine, abdomen and pelvis.

(a) The lumbar spine, abdomen, and pelvis con-
sist of the part of the torso assembly shown by
number SA 103C 030 on drawing SA 103C 001
and conform to each of the applicable drawings
listed under this number on drawing SA 103C
002, sheets 10 and 11.

(b) When subjected to continuously applied
force in accordance with paragraph (c) of this sec-
tion, the lumbar spine assembly shall flex by an
amount that permits the rigid thoracic spine to
rotate from its initial position in accordance with
Figure 18 of this subpart by 40 degrees at a force
level of not less than 34 pounds and not more
than 47 pounds, and straighten upon removal of
the force to within 5 degrees of its initial position.

(c) Test Procedure: (1) The dummy with lower
legs removed is positioned in an upright seated
position on a seat as indicated in Figure 18,
ensuring that all dummy component surfaces are
clean, dry and untreated unless otherwise speci-
fied.

(2) Attach the pelvis to the seating surface
by a bolt C/328, modified as shown in Figure
18, and the upper legs at the knee axial rotation
joints by the attachments shown in Figure 18.
Tighten the mountings so that the pelvis-lumbar
joining surface is horizontal and adjust the
femur ball-flange screws at each hip socket
joint to 50 inch pounds torque. Remove the
head and the neck and install a cylindrical alu-
minum adapter 2.0 inches in diameter and 2.80
inches long in place of the neck.

(3) Flex the thorax forward 50 degrees and
then rearward as necessary to return to its ini-
tial position in accordance with Figure 18
unsupported by external means.

(4) Apply a forward pull force in the
midsagittal plane at the top of the neck adapter,

so that at 40 degrees of the lumbar spine
flexion the applied force is perpendicular to the
thoracic spine box. Apply the force at any torso
deflection rate between 0.5 and 1.5 degrees per
second up to 40 degrees of flexion but no fur-
ther; continue to apply for 10 seconds the force
necessary to maintain 40 degrees of flexion,
and record the highest applied force at that
time. Release all force as rapidly as possible
and measure the return angle 3 minutes after
the release.

§572.20 Limbs.

The limbs consist of the assemblies shown on
drawing SA 103C 001 as Nos. SA 103C 041, S A
103C 042, SA 103C 051, SA 103C 052, SA 103C
061, SA 103C 062, SA 103C 071,SA 103C 072,
SA 103C 081, SA 103C 082, and conform to
each of the applicable drawings listed under their
respective numbers of the drawing SA 103C 002,
sheets 12 through 21.

§572.21 Test conditions and Instrumentation.

[(a)(1) The test probe used for head and tho-
racic impact tests is a cylinder 3 inches in diame-
ter, 13.8 inches long and weighs 10 lbs., 6 ozs.
Its impacting end has a flat right face that is rigid
and that has an edge radius of 0.5 inches.

(2) The head and thorax assembly may be
instrumented with a Type A or Type C acceler-
ometer.

(i) Type A accelerometer is defined in
drawing SA-572 SI.

(ii) Type C accelerometer is defined in
drawing SA-572 S2.

(b) Head Accelerometers. Install one of the tri-
axial accelerometers specified in §S72. 21(a)(2) on
a mounting block located on the horizontal trans-
verse bulkhead as shown in the drawings
subreferenced under assembly SA 103C 010 so
that the seismic mass centers of each sensing ele-
ment are positioned as specified in this paragraph,
relative to the head accelerometer reference point
located at the intersection of a line connecting the
longitudinal centerlines of the transfer pins in the
side of the dummy head with the midsagittal
plane of the dummy head.

(1) The sensing elements of the Type C tri-
axial accelerometer are aligned as follows:

(i) Align one sensitive axis parallel to the
vertical bulkhead and coincident with the
midsagittal plane, with the seismic mass cen-

ter located 0.2 inches dorsal to, and O.I
inches inferior to the head accelerometer ref- ^m
erence point. ^B

(ii) Align the second sensitive axis with
the horizontal plane, perpendicular to the
midagittal plane, with the seismic mass cen-
ter located 0.1 inches inferior, 0.4 inches to
the right of, and 0.9 inches dorsal to the
head accelerometer reference point.

(iv) All seismic mass centers are posi-
tioned with ±0.05 inches of the specified
locations.

(2) The sensing elements of the Type A tri-
axial accelerometer are aligned as follows:

(i) Align one sensitive axis parallel to the
vertical bulkhead and coincident with
midsagittal planes, with the seismic mass
center located from 0.2 to 0.47 inches dorsal
to, from 0.01 inches inferior to 0.21 inches
superior, and from 0.0 to 0.17 inches left of ^
the head accelerometer reference point.

(ii) Align the second sensitive axis with
the horizontal plane perpendicular to the
medsagittal plane, with the seismic mass cen-
ter located 0.1 to 0.13 inches inferior to, 0.17
to 0.4 inches to the right of, and 0.47 to 0.9
inches dorsal of the head accelerometer ref-
erence point.

(iii) Align the third sensitive axis so that
it is parallel to the midsagittal and horizontal
planes, with the seismic mass center located
0.1 inches inferior to, 0.6 inches dorsal to,
and 0.4 inches to the right of the head accel-
erometer reference point,
(c) Thorax Accelerometers. Install one of the
triaxial accelerometers specified in § 572.21(a)(2)
on a mounting plate attached to the vertical trans-
verse bulkhead shown in the drawing
subreferenced under assembly NO. SA 103C 030
in drawing SA 103 001, so that the seismic mass
centers of each sensing element are positioned as
specified in this paragraph, relative to the thorax
accelerometer reference point located in the j

midsagittal plane 3 inches above the top surface ^J|
of the lumbar spine, 0.3 inches doral to the accel- -^

erometer mounting plate surface.

PART 572-10

(1) The sensing elements of the Type C tri-
axial accelerometer are ahgned as follows:

i (i) Align one sensitive axis parallel to the

' vertical bulkhead and midsagittal planes,

with seismic mass center located 0.2 inches
to the left of, 0.1 inches inferior to, and 0.2
inches ventral to the thorax accelerometer
reference point.

(ii) Align the second sensitive axis so that
it is in the horizontal transverse plane, and
perpendicular to the midsagittal plane, with
the seismic mass center located 0.2 inches to
the right of, 0.1 inches inferior to, and 0.2
inches ventral to the thorax accelerometer
reference point.

(iii) Align the third sensitive axis so that
it is parallel to the midsagittal and horizontal
planes with the seismic mass center located
0.2 inches superior to, 0.5 inches to the right
of. and 0. 1 inches ventral to the thorax accel-
erometer reference points, (iv) All seismic
mass centers shall be positioned within ±0.05
inches of the specified locations.

(2) The sensing elements of the Type A tri-
axial accelerometer are aligned as follows:

>(i) Align one sensitive axis parallel to the
vertical bulkhead and midsagittal planes,
with the seismic mass center located from
0.2 inches left to 0.28 inches right, from 0.5
to 0,15 inches inferior to, and from 0.15 to
0.25 inches ventral of the thorax acceler-
ometer reference point.

(ii) Align the second sensitive axis so that
it is in the horizontal transverse plane and
perpendicular to the midsagittal plane, with
the seismic mass center located from 0.06
inches left to 0.2 inches right of, from 0.1
inches inferior to 0.24 inches superior, and
0.15 to 0.25 inches ventral to the thorax
accelerometer reference point.

(iii) Align the third sensitive axis so that
it is parallel to the midsagittal and horizontal
planes, with the seismic mass center located
0.15 to 0.25 inches superior to, 0.28 to 0.5
inches to the right of, and from 0.1 inches
ventral to 0.19 inches dorsal to the thorax
accelerometer reference point. (55 F.R.
30465— July 26. 1990. Effective: August 27.
1990)]

I (d) The outputs of accelerometers installed in

the dummy, and of test apparatus specified by this
part, are recorded in individual data channels that

conform to the requirements of SAE Rec-
ommended Practice J211a, December 1971, with
channel classes as follows:

(1) Head acceleration — Class 1,000.

(2) Pendulum acceleration^ — Class 60.

(3) Thorax acceleration — Class 180.

(e) The mountings for accelerometers have no
resonance frequency less than 3 times the cut-off
frequency of the applicable channel class.

(0 Limb joints are set at the force between 1-
2g, which just supports the limbs' weight when
the limbs are extended horizontally forward. The
force required to move a limb segment does not
exceeed 2g throughout the range of limb motion.

(g) Performance tests are conducted at any
temperature from 66° F to 78° F and at any rel-
ative humidity from 10 percent to 70 percent after
exposure of the dummy to these conditions for a
period of not less than 4 hours.

(h) For the performance tests specified
§§572.16, 572.18, and 572.19, the dummy is
positioned in accordance with Figures 16, 17, and
18 as follows:

(1) The dummy is placed on a flat, rigid,
clean, dry, horizontal surface of teflon sheeting
with a smoothness of 40 microinches and
whose length and width dimensions are not less
than 16 inches, so that the dummy's midsagittal
plane is vertical and centered on the test sur-
face. For head tests, the seat has a vertical back
support whose top is 12.4 ± 0.2 inches above
the seating surface. The rear surfaces of the
dummy's shoulders and buttocks are touching
the back support as shown in Figure 16. For
thorax and lumbar spine tests, the seating sur-
face is without the back support as shown in
Figures 17 and 18 respectively.

(2) The shoulder yokes are adjusted so that
they are at the midpoint of their anterior-pos-
terior travel with their upper surfaces hori-
zontal.

(3) The dummy is adjusted for head impact
and lumbar flexion tests so that the rear sur-
faces of the shoulders and buttocks are tangent
to a transverse vertical plane.

(4) The arms and legs are positioned so that
their centerlines are in planes parallel to the
midsagittal plane.

(i) The dummy's dimensions are specified in
drawings No. SA 103C 002, sheets 22 through
26.

PART 572-1 1

(Rev. 7/26/90)

(j) Performance tests of the same component, (k) Surfaces of the dummy components are not
segment, assembly or fully assembled dummy are painted except as specified in this part or in draw-
separated in time by a period of not less than 20 ings subtended by this part,
minutes unless otherwise specified.

PART 572-12

Inertial Properties of Pendulum
Without Test Specimen.
Weight 65.2 lbs.

Moment of Inertia 24.5 lb. -ft. Sec.
About Pivot Axis

5-"/,e" Ref

CG of Pendulum
Apparatus Without
Test Specimen

Accelerometer

Aluminum Honeycomb
(Hexcell 1.8 Ibs./cu. ft.)
Ref.

CG of Test Specimen

Plate (Sharp Edges)

Leading Edge of Necl<
Must Be Alligned With
Leading Edge of Pendulum

PART 572-Subpart C-ART PAGE 1

mpactor Support Wire

PART 572-Subpart C-ART PAGE 2

Impactor Face to Be Vertical ± 2°
at Contact of Chest

Impactor Support Wire

PART 572-Subpart C-ART PAGE

.00" Radius

Pull Force in the Mid-Sagittal
Plane Perpendicular to the Chest
Instrument Cavity Rear Face.

.125^

PART 572-Subpart C-ART PAGE 4

Subpart D— Six-Month-Old Infant

)§ 572.25 General Description.
(a) The infant dummy is specified in its
entirety by means of 5 drawings (No. SA 1001)
and a construction manual, dated July 2, 1974,
which describe in detail the materials and the
procedures involved in the manufacturing of this
dummy.

(b) The drawings, specifications, and construc-
tion manual referred to in this regulation that are
not set forth in full are hereby incorporated in this
part by reference. These materials are thereby
made part of this regulation. The Director of the
Federal Register has approved the materials incor-
porated by reference. For materials subject to
change, only the specific version approved by the
Director of the Federal Register and specifed in
the regulation are incorporated. A notice of any
change will be published in the Federal Register.
As a convenience to the reader, the materials
incorporated by reference are listed in the Finding
Aid Table found at the end of this volume of the
Code of Federal Regulations.

5109, Docket Section, National Highway Traffic
Safety Administration, 400 Seventh Street, S.W.,
Washington, D.C. 20590. Copies may be obtained
from Rowley-Scher Reprographics, Inc., 1111
14th Street, N.W., Washington, D.C. 20005,
((202) 628-6667 or 408-8789). The materials are
also on file in the reference library of the Office
of the Federal Register, National Archives and
Records Administration , Washington, D.C.

(d) The structural properties of the dummy are
such that the dummy conforms to this part in
every respect both before and after being used in
vehicle tests specified in Standard No. 2 1 3 of this
chapter (§571.213).

Subpart E— Hybrid III Test Dummy

Source: 51 FR 26701, July 25, 1986, unless
otherwise noted.

Ejfective Date Note and Optional Compliance
Provisions: At 51 FR 26701, July 25,1986, Sub-
part E — Hybrid III Test Dummy was added,
effective October 29, 1986. As of that date,
manufacturers have the option of using either the
Part 572 test dummy (Subpart B) or the Hybrid

III test dummy until August 31, 1991. As of
September 1, 1991, the Hybrid III will replace the
Part 572 test dummy (Subpart B) and be used as
the exclusive means of determining a vehicle's
conformance with the performance requirements
of Standard No. 208 (§571.208).

§572.30 Incorporated Materials.

(a) The drawings and specifications referred to
in this regulation that are not set forth in full are
hereby incorporated in this part by reference. The
Director of the Federal Register has approved the
materials incorporated by reference. For materials
subject to change, only the specific version
approved by the Director of the Federal Register
and specified in the regulation are incorporated. A
notice of any change will be published in the
Federal Register. As a convenience to the reader,
the materials incorporated by reference are listed
in the Finding Aid Table found at the end of this
volume of the Code of Federal Regulations.

(b) The materials incorporated in this part by
reference are available for examination in the
general reference section of Docket 79-04,
Docket Section, National Highway Traffic Safety
Administration, Room 5109, 400 Seventh Street,
S.W., Washington, D.C. 20590. Copies may be
obtained from Rowley-Scher Reprographics, Inc.,
1216 K Street, N.W., Washington, D.C. 20005,
((202)628-6667). The drawings and specifications
are also on file in the reference library of the
Office of the Federal Register, National Archives
and Records Administration, Washington, D.C.

§572.31 General Description.

(a) The Hybrid III 50th percentile size dummy
consists of components and assemblies specified
in the Anthropomorphic Test Dummy drawings
and specifications package which consists of the
following six items:

(1) The Anthropomorphic Test Dummy Parts
List, dated [March 10, 1988], and containing
13 pages, and Parts list Index, dated [March
10, 1988], containing [8] pages, (57 F.R.
479009— October 14, 1992. Effective: October 14.
1992)

(2) A listing of Optional Hybrid III Dummy
Transducers, dated April 22, 1986, contain 4
pages.

(3) A General Motors Drawing package
identified by GM drawing No. 78051-218 revi-
sion R and subordinate drawings.

PART 572-13

(Rev. 10/14/92)

(4) Disassembly. Inspection, Assembly and
Limbs Adjustment Procedures for the Hybrid
III Dummy, dated July 15, 1986,

(5) Sign Convention for the signal outputs of
Hybrid III Dummy Transducers, dated July 15,
1986,

(6) Exterior Dimensions of the Hybrid III
Dummy, dated July 15, 1986.

(b) The dummy is made up of the following
component assemblies:

Drawing
Number

Revi-
sion

78051-61 Head Assembly— Complete— (T)

78051-90 Neck Assembly— Complete— (A)

78051-89 Upper Torso Assembly— (K)

Complete —
78051-70 Lower Torso Assembly— Without (D)

Pelvic Instrumentation Assem-
bly, Drawing Number 78051-59
86-5001-001 Leg Assembly— Complete (LH)— (E)
86-5001-002 Leg Assembly— Complete (RH)— (E)
78051-123 Arm Assembly— Complete (D)

(LH)-
78051-124 Arm Assembly— Complete (D)

(RH)—

(c) Any specifications and requirements set
forth in this part supercede those contained in
General Motors Drawing No. 78051-218, revision
P.

(d) Adjacent segments are joined in a manner
such that throughout the range of motion and also
under crash-impact conditions, there is no contact
between metallic elements except for contacts that
exist under static conditions.

(e) The weights, inertial properties and centers
of gravity location of component assemblies shall
conform to those listed in drawing 78051-338,
revision S.

(f) The structural properties of the dummy are
such that the dummy conforms to this part in
every respect both before and after being used in
vehicle test specified in Standard No. 208 of this
Chapter (S 571.208).

§572.32 Head.

(a) The head consists of the assembly shown in
the drawing 78051-61. revision T, and shall con-
form to each of the drawings subtended therein.

(b) When the head (drawing 78051-61, revision
T) with neck transducer structural replacement
(drawing 78051-383, revision F) is dropped from
a height of 14.8 inches in accordance with para-
graph (c) of this section, the peak resultant accel-

erations at the location of the accelerometers
mounted in the head in accordance with 572.36(c) ^^
shall not be less than 225g, and not more than ^P
275g. The acceleration/time curve for the test
shall be unimodal to the extent that oscillations
occurring after the main acceleration pulse are
less than ten percent (zero to peak) of the main
pulse. The lateral acceleration vector shall not
exceed 15g (zero to peak).

(c) Test Procedure. (1) Soak the head assembly
in a test environment at any temperature between
66 degrees F to 78 degrees F and at a relative
humidity from 10% to 70% for a period of at
least four hours prior to its application in a test.

(2) Clean the head's skin surface and the
surface of the impact plate with 1,1,1
Trichlorethane or equivalent.

(3) Suspend the head, as shown in Figure 19,
so that the lowest point on the forehead is 0.5
inches below the lowest point on the dummy's
nose when the midsagittal plane is vertical.

(4) Drop the head from the specified height
by means that ensure instant release onto a rig-
idly supported flat horizontal steel plate, which
is 2 inches thick and 2 feet square. The plate

shall have a clean, dry surface and any ^
microfinish of not less than 8 microinches
(rms) and not more than 80 microinches (rms).

(5) Allow at least 2 hours between succes-
sive tests on the same head.

§572.33 Neck.

(a) The neck consists of the assembly shown in
drawing 78051-90, revision A and conforms to
each of the drawings subtended therein.

(b) When the neck and head assembly (consist-
ing of the parts 78051-61, revision T; - 84; -90,
revision A; -96; -98; -303, revision E; -305;
-306; -307, revision X, which has a neck trans-
ducer (drawing 83-5001-008) installed in
conformance with 572.36(d), is tested in accord-
ance with paragraph (c) of this section, it shall
have the following characteristics:

(1) Flexion, (i) Plane D, referenced in Figure
20, shall rotate between 64 degrees and 78
degrees, which shall occur between 57 milli-
seconds (ms) and 64 ms from time zero. In first
rebound, the rotation of plane D shall cross
degrees between 113 ms and 128 ms.

(ii) The moment measured by the neck (|

transducer (drawing 83-5001-008) about the '^

occipital condyles, referenced in Figure 20,

PART 572-14

shall be calculated by the following formula:
Moment (Ibs-ft) = My + 0.02875 x F,-
where My is the moment measured in Ibs-ft
by the moment sensor of the neck transducer
and Fx is the force measured in lbs by the
X axis force sensor of the neck transducer.
The moment shall have a maximum value
between 65 Ibs-ft occurring between 47 ms
and 58 ms, and the positive moment shall
decay for the first time to Ib-ft between 97
ms and 107 ms.

(2) Extension, (i) Plane D, referenced in Fig-
ure 21, shall rotate between 81 degrees and 106
degrees, which shall occur between 72 and 82
ms from time zero. In first rebound, the rota-
tion of plane D shall cross degree between
147 and 174 ms.

(ii) The moment measured by the neck
transducer (drawing 83-5001-008) about the
occipital condyles, referenced in Figure 21,
shall be calculated by the following formula:
Moment (Ibs-ft) = My + 0.02875 x Fx-
where M is the moment measured in Ibs-ft
by the momensensor of the neck transducer
and Fx is the force measure measured in lbs
by the x axis force sensor of the neck trans-
ducer. The moment shall have a minimum
value between -39 Ibs-ft and -59 Ibs-ft,
which shall occur between 65 ms and 79 ms,
and the negative moment shall decay for the
first time to Ib-ft between 120 ms and 148
ms.

(3) Time zero is defined as the time of con-
tact between the pendulum striker plate and the
aluminum honeycomb material.

(c) Test Procedure. (1) Soak the test material
in a test environment at any temperature between
69 degrees F to 72 degrees F and at a relative
humidity from 10% to 70% for a period of at
least four hours prior to its application in a test.

(2) Torque the jamnut (78051-64) on the
neck cable (78051-301. revision E) to 1.0 Ibs-
ft ±. Ibs-ft.

(3) Mount the head-neck assembly, defined
in paragraph (b) of this section, on a rigid pen-
dulum as shown in Figure 22 so that the head's
midsagittal plane is vertical and coincides with
the plane of motion of the pendulum's longitu-
dinal axis.

(4) Release the pendulum and allow it to fall
freely from a height such that the tangential
velocity at the pendulum accelerometer center-

line at the instance of contact with the honey-
comb is 23.0 ft/sec ± 0.4 ft/sec. for flexion test-
ing and 19.9 ft/sec ± 0.4 ft/sec. for extension
testing. The pendulum deceleration vs. time
pulse for flexion testing shall conform to the
characteristics shown in Table A and the
decaying deceleration-time curve shall first
cross 5g between 34 ms and 42 ms. The penhe
Im deceleration vs. time pulse for extension
testing shall conform to the characteristics
shown in Table B and the decaying decelera-
tion-time curve shall cross 5g between 38 ms
and 46 ms.

Table A

Flexion Pendulum Deceleration vs conme Pulse

Time (ms)

Flesion deceleration level (g)

Any other time above 30 it

22.50-27.50

17.60-22.60

12.50-18.50

IS 29 maximum

Table B

Extension Pendulum Deceleration vs. Time Pulse

Time ims)

Extension deceleration level (g)

10
20
30
Any other time above 30 it

17.20-21.00
14.00-19.00
11.00-16.00
IS 22 maximum

(5) Allow the neck to flex without impact of
the head or neck with any object during the ts
on

§572.34 Thorax.

(a) The thorax cons at of the upper torso
assembly in drawing 78051-89, revision [K] and
shall conform to each of the drawings subtended
therein.

(b) [When impacted by a test probe conform-
ing to S 572.36(a) at 22 fps ± .40 fps in accord-
ance with paragraph (c) ofd nos section, tthe
borax of a complete dummy assembly (78051-
218, Revision R) with left and right shoeg a
51-294 and -295) removed, shall resist with a
force of 1242.5 pounds ± 82.5 pounds measured
by the test probe and shall have a sternum
displacement measured relativg a spine of 2.68
inches + 0.18 inches. The internal hysteresis in
each impact shall be more than 69% but less than
85%. The force measured is the product of pen-
dulum mass and deceleration.! (53 F.R. 8755 —
March 17, 1988. Effective: March 17, 1988)

PART 572

(Rev. 3/17/88)

(c) Test procedure. (1) Soak the test dummy in
an environment with a relative humidity from
10% to 70% until the temperature of the ribs of
the test dummy have stabilized at a temperature
between 69 degrees F and 72 degrees F.

(2) [Seat the dummy without back and arm
supports on a surface as shown in Figure 23,
and set the angle of the pelvic bone at 13
degrees plus or minus 2 degrees, using the
procedure described in S 11.4.3.2 of Standard
No. 208 (S 571.208 of this chapter).] (53 F.R.
8755— March 17, 1988. Effective: March 17,
1988).

(3) Place the longitudinal centerline of the
test probe so that it is .5 in ± .04 in. below the
horizontal centerline of the No. 3 Rib (ref-
erence drawin number 79051-64, revision A-
M) as shown Figure 23.

(4) Align the test probe specified in
S572. 36(a) so that at impact it longitudinal
centerline coincides within .5 degree of a hori-
zontal line in the dummy's midsagittal plane.

(5) Impact the thorax with the test probe so
that the longitudinal centerline of the test probe
falls within 2 degrees of a horizontal line in the
dummy's midsagittal plane at the moment of
impact.

(6) Guide the probe during impact so that it
moves with no significant lateral, vertical, or
rotational movement.

(8) Measure hysteresis by determining the
ratio of the area between the loading and
unloading portions of the force deflection curve
to the area under the loading portion of the
curve.

§572.35 Limbs.

(a) The limbs consist of the following assem-
blies: leg assemblies 86-5001-001 and -002 and
arm assemblies 78051-123, revision D, and -124,
revision D, and shall conform to the drawings
subtended therein.

(b) [When each knee of the leg assemblies is
impacted, in accordance with paragraph (c) of this
section, at 6.9 ft/sec ± 0.10 ft/sec, by the pen-

dulum defined in S 572.36(b), the peak knee
impact force, which is a product of pendulum
mass and acceleration, shall have a minimum ^^
value of not less than 1060 pounds and a maxi-
mum value of not more than 1300 pounds.] (53
F.R. 8755— March 17, 1988. Effective: March 17,
1988)

(c) Test Procedure. (1) The test material con-
sists of leg assemblies (86-5001-001) left and
(-002) right with upper leg assemblies (78051-
46) left and (78051-^7) right removed. The load
cell simulator (78051-319, revision A) is used to
secure the knee cap assemblies (79051-16, revi-
sion B) as shown in Figure 24.

(2) Soak the test material in a test environ-
ment at any temperature between 66 degrees F
to 78 degrees F and at a relative humidity from
10% to 70% for a period of at least four hours
prior to its application in a test.

(3) Mount the test material with the leg
assembly secured through the load cell simula-
tor to a rigid surface as shown in Figure 24. No
contact is permitted between the foot and any
other exterior surfaces.

(4) Place the longitudinal centerline of the

test probe so that at contact with the knee it is fl
colinear within 2 degrees with the longitudinal
centerline of the femur load cell simulator.

(5) Guide the pendulum so that there is no
significant lateral, vertical or rotational move-
ment at time zero.

(6) Impact the knee with the test probe so
that the longitudinal centerline of the test probe
at the instant of impact falls within .5 degrees
of a horizontal line parallel to the femur load
cell simulator at time zero.

(7) Time zero is defined as the time of con-
tact between the test probe and the knee.

§572.36 Test Conditions and instrumentation.

(a) The test probe used for thoracic impact tests
is a 6 inch diameter cylinder that weighs 51.5
pounds including instrumentation. Its impacting
end has a flat right angle face that is rigid and has
an edge radius of 0.5 inches. The test probe has
an accelerometer mounted on the end opposite
from impact with its sensitive axis colinear to the
longitudinal centerline of the cylinder.

(b) The test probe used for the knee impact I
tests is a 3 inch diameter cylinder that weighs 1 1
pounds including instrumentation. Its impacting

(Rev. 3/17/88)

PART 572-16

end has a flat right angle face that is rigid and has
an edge radius of 0.2 inches. The test probe has
an accelerometer mounted on the end opposite
from impact with its sensitive axis colinear to the
longitudinal centeriine of the cylinder.

(c) Head accelerometers shall have dimensions,
response characteristics and sensitive mass loca-
tions specified in drawing 78051-136, revision A
or its equivalent and be mounted in the head as
shown in drawing 78051-61, revision T. and in
the assembly shown in drawing 78051-218, revi-
sion R.

(d) The neck transducer shall have the dimen-
sions, response characteristics, and sensitive axis
locations specified in drawing 83-5001-008 or its
equivalent and be mounted for testing as shown
in drawing 79051-63, revision W, and in the
assembly shown in drawing 78051-218, revision
R.

(e) The chest accelerometers shall have the
dimensions, response characteristics, and sensitive
mass locations specified in drawing 78051-136,
revision A or its equivalent and be mounted as
shown with adaptor assembly 78051-116, revision
D for assembly into 78051-218, revision R.

(f) The chest deflection transducer shall have
the dimensions and response characteristics speci-
fied in drawing 78051-342. revision A or equiva-
lent and be mounted in the chest deflection trans-
ducer assembly 87051-317. revision A for assem-
bly into 78051-218. revision R.

(g) The thorax and knee impactor
accelerometers shall have the dimensions and
characteristics of Endevco Model 7231c or
equivalent. Each accelerometer shall be mounted
with its sensitive axis colinear with the pen-
dulum's longitudinal centeriine.

(h) The femur load cell shall have the dimen-
sions, response characteristics, and sensitive axis

locations specified in drawing 78051-265 or its
equivalent and be mounted in assemblies 78051-
46 and -47 for assembly into 78051-218, revision
R.

(i) The outputs of acceleration and force-sens-
ing devices installed in the dummy and in the test
apparatus specified by this part are recorded in
individual data channels that conform to the
requirements of SAE Recommended Practice
J211, JUN 1980, "Instrumentation for Impact
Tests." with channel classes as follows:

(1) Head acceleration— Class 1000

(2) Neck force— Class 60

(3) Neck pendulum acceleration — Class 60

(4) Thorax and thorax pendulum accelera-
tion—Class 180

(5) Thorax deflection— Class 180

(6) Knee pendulum acceleration — Class 600

(7) Femur force— Class 600

(j) Coordinate signs for instrumentation polarity
conform to the sign convention shown in the
document incorporated by § 572.31(a)(5).

(k) The mountings for sensing devices shall
have no resonance frequency within range of 3
times the frequency range of the applicable chan-
nel class.

(1) Limb joints are set at Ig, barely restraining
the weight of the limb when it is extended hori-
zontally. The force required to move a limb seg-
ment shall not exceed 2g throughout the range of
limb motion.

(m) Performance tests of the same component,
segment, assembly, or fully assembled dummy are
separated in time by a period of not less than 30
minutes unless otherwise noted.

(n) Surfaces of dummy components are not
painted except as specified in this part or in draw-
ings subtended by this part.

PART 572-17

(10/30/90)

Drop height
376mm
(14.8 in.)

"A"

"B"

Chrome-plated steel block

50.8 X 610 X 610 mm (2 x 24 x 24 in.;

8 to 80 rms microinch/inch finish

Centerline of 1.6 mm
(0.062 in.) diameter
holes in skull

Distance "A'— Distance "B" = 0.0 mm

I 1

Note: Tolerance on test setup dimensions ±1 mm (0.04 in.)

Figure 19. Test Set-up Specifications

PART 572-Subpart E-ART PAGE 1

Pendulum Centerline

Bracket Ass'y— Neck
Adjusting, Upper
(P/N 78051-307)

BIB Sinnulator
(P/N 78051-84)

Neck Ass'y
(P/N 78051-90)

Plane pP^

(Ref. dwg. 78051-77)
perpendicular to
pendulum centerline
± 1°

13.5mm ± .5
(.53 inches ± .02)

Centerline
Mounting Screw
(Ref. dwg. 78051-96)

Bracket— Neck
Adjusting, Lower
(P/N 78051-303)

Occipital Condyles

Note; Pendulum shown at Time Zero position

Figure 20. Flexion— Test Setup Specifications

PART 572-Subpart E-ART PAGE 2

37.3 mm ± .5
(1.47 inches ± .02)

Centerline
Mounting Screw
(Ret. dwg. 78051-96)

Bracket— Neck
Adjusting, Lower
(P/N 78051-303)

Occipital Condyles

Head Ass'y
(P/N 78051-61)

Pendulum Centerline

Bracket Ass'y— Neck
Adjusting, Upper
(P/N 78051-307)

BIB Simulator
(P/N 78051-84)

Neck Ass'y
(P/N 78051-90)

Plane [3
(Ret. dwg. 78051-77)
perpendicular to
pendulum centerline
+ 1°

Note: Pendulum shown at Time Zero position

Figure 21. Flexion— Test Setup Specifications

PART 572-Subpart E-ART PAGE

Structural steel tube
4.8 mm (0.1875 in.)

Pivot 50.8 mm (2 in.) Dia

Inertial properties of pendulum.
Mounting plate and mounting
hardware without test specimen
Weight 29.57 kg (65.21 lbs).
Moment of inertia 33.2 kg-m^
(294 in.-lb-sec2) about pivot axis

CG of pendulum
apparatus without
test specimen

Accelerometer

Mounting Plate

Accelerometer

linum honeycomb
J ^^ hexcel 28.8 kg/m3

38.1 mm Ref.
(1.5 in.)

(1.8 Ib/ft3) Ref.
Before testing, precrush the
honeycomb material with the pendulum
to assure that 90% to 100% of the
honeycomb surface is contacting the
pendulum striker plate.

Pendulum Striker Plate (sharp edges)
76.2 X 152.4 X 9.5 mm
(3 X 6 X % in.)

Figure 22. Pendulum Specifications

PART 572-Subpart E-ART PAGE 4

Pendulum accelerometer
(ENDEVCO Model 7231C or equivalent)
mounted with sensitive axis parallel
to pendulum longitudinal centerline.

Centerline of arms horizontal ±2°
(Ret dwg 78051-123 and dwg 78051-124)

No. 3 Rib Centerline
Horizontal ±0.5°
t^-^f dwg 78051-31)

Pendulum Centerline
Horizontal ±0.5°

Seating Surface
Horizontal ±0.5°

NOTE:

A) No external support is required on the dummy to meet setup specifications.

B) The midsagittal plane of the dummy is vertical (±1°) and within 2°
of the centerline of the pendulum.

C) The midsagittal plane of the dummy is centered on the centerline of
the pendulum within 3 mm (0.12 in.).

Figure 23. Test Set-up Specifications

PART 572-Subpart E-ART PAGE 5

Torque two femur load cell simulator
mounting bolts (P/N 78051-99 and
P/N 78051-100) to 41 Newton Meters
(30 ft-lbs).

Pendulum accelerometer

(ENDEVCO Model 7231C or equivalent)

mounted with sensitive axis

parallel to pendulum

longitundinal centerline.

Adjust knee joint
torque to 1-2 range
before each test.

Ankle Pivot

Pendulum Centerline
Horizontal ±0.5°

Rigid Pendulum Impactor

Figure 24. Test Set-up Specifications

PART 572- Subpart E-ART PAGE

Subpart F— Side Impact Dummy 50th
Percentile Male
[§572.40 Incorporated Materials.

(a) The drawings, specifications, and computer
program referred to in this regulation that are not
set forth in full are hereby incorporated in this
part by reference. These materials are there by
made part of this regulation. The Director of the
Federal Register has approved the materials incor-
porated by reference. For materials subject to
change, only the specific version approved by the
Director of the Federal Register and specified in
the regulation are incorporated. A notice of any
change will be published in the Federal Register.
As a convenience to the reader, the materials
incorporated by reference are listed in the Finding
Aid Table found at the end of this volume of the
Code of Federal Regulations.

(b) The materials incorporated in this part by
reference are available for examination in the
general reference section of Docket 79-04,
Docket Section, National Highway Traffic Safety
Administration, Room 5109, 400 Seventh Street,
S.W. Washington, D.C. Copies may be obtained
from Rowley-Scher Reprographics, Inc., 1111
14th Street, N.W.. Washington, D.C. 20005, tele-
phone (202) 628-6667 or 408-8789.

[§572.41 General Description.

(a) The dummy consists of component parts
and component assemblies (SA-SID-MOOl and
SA-SID-MOOIA) which are described in approxi-
mately 250 drawings and specifications that are
set forth in Part 572.5(a) of this Chapter with the
following changes and additions which are
described in approximately 85 drawings and
specifications:

(1) The head assembly consists of the assem-
bly specified in Subpart B (§ 572.6(a)) and con-
forms to each of the drawings subtended under
drawing SA 150 M 010 and drawings specified
in SA-SID-MOIO of this subpart.

(2) The neck assembly consists of the assem-
bly specified in Subpart B (§ 572.7(a)) and con-
forms to each of the drawings subtended under
drawing SA-150-M020 and drawings shown in
SA-SID-MOIO.

(3) The thorax assembly consists of the
assembly shown as number SID-053 and con-
forms to each applicable drawing subtended by
number SA-SID-M030.

(4) The lumbar spine consists of the assem-
bly specified in Subpart B (§ 572.9(a)) and con-
forms to drawing SA-150-M050 and drawings
subtended by SA-SID-M050 specified by this
part.

(5) The abdomen and pelvis consist of the
assembly specified in Subpart B (§572.9) and
conform to the drawings subtended by SA-
150-M060 and drawings subtended by SA-
SID-M060 specified by this Subpart.

(6) The lower limbs consist of the assemblies
specified in Subpart B (§572.10) shown as
SA-150-M080 and SA-150-M081 in Figure 1
and SA-SID-M080 and SA-SID-M081 and
conform to the drawings subtended by those
numbers.

(b) The structural properties of the dummy are
such that the dummy conforms to the require-
ments of this subpart in every respect both before
and after being used in vehicle tests specified in
Standard No. 214 (Part 571.214 of this Chapter).

(c) Disassembly, inspection, and assembly
procedures; external dimensions and weight; and
a dummy drawing list are set forth in the Side
Impact Dummy (SID) User's Manual, dated July
1990.

[§572.42 Thorax.

(a) When the thorax of a completely assembled
dummy (SA-SID-MOOl A), appropriately assem-
bled for right or left side impact, is impacted by
a test probe conforming to § 572.44(a) at 14 fps
in accordance with paragraph (b) of this section,
the peak accelerations at the location of the
accelerometers mounted on the thorax in accord-
ance with § 572.44(b) shall be:

(1) for the accelerometer at the top of the
Rib Bar on the struck side (LUR or RUR) not
less than 37 g's and not more than 46 g's.

(2) for the accelerometer at the bottom of the
Rib Bar on the struck side (LLR or RLR) not
less than 37 g's and not more than 46 g's.

(3) for the lower thoracic spine (T12) not
less than 15 g's and not more than 22 g's.

(b) Test Procedure. (1) Adjust the dummy legs
as specified in § 572.44(f). Seat the dummy on a
seating surface as specified in § 572.44(h) with
the limbs extended horizontally forward.

(2) Place the longitudinal centerline of the
test probe at the lateral side of the chest at the
intersection of the centerlines of the third rib
and the Rib Bar on the desired side of impact.

PART 572-19

(Rev. 10/30/90)

This is the left side if the dummy is to be used
on the driver's side of the vehicle and the right
side if the dummy is to be used on the pas-
senger side of the vehicle. The probe's center-
line is perpendicular to the thorax's midsagittal
plane.

(3) Align the test probe so that its longitu-
dinal centerline coincides with the line formed
by the intersection of the transverse and frontal
planes perpendicular to the chest's midsagittal
plane passing through the designated impact
point.

(4) Position the dummy as specified in
§ 572.44(h), so that the thorax's midsagittal
plane and tangential plane to the Hinge Mount-
ing Block (Drawing SID-034) are vertical.

(5) Impact the thorax with the test probe so
that at the moment of impact at the designated
impact point, the probe's longitudinal centerline
falls within 2 degrees of a horizontal line per-
pendicular to the dummy's midsagittal plane
and passing through the designated impact
point.

(6) Guide the probe during impact so that it
moves with no significant lateral, vertical or
rotational movement.

(7) Allow a time period of at least 20 min-
utes between successive tests of the chest.

[§ 572.43 Lumbar spine and pelvis.

(a) When the pelvis of a fully assembled
dummy (SA-SID-MOOIA) is impacted laterally by
a test probe conforming to § 572.44(a) at 14 fps
in accordance with paragraph (b) of this section,
the peak accleration at the location of the acceler-
ometer mounted in the pelvis cavity in accordance
with § 572.44(c) shall be not less than 40g and
not more han 60g. The acceleration-time curve for
the test shall be unimodal and shall lie at or
above the ±20g level for interval not less than 3
milliseconds and not more than 7 milliseconds.

(b) Test Procedure. (1) Adjust the dummy legs
as specified in §572.44(0- Seat the dummy on a
seating surface as specified in § 572.44(h) with