[Federal Register Volume 64, Number 79 (Monday, April 26, 1999)]
[Proposed Rules]
[Pages 20245-20248]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-10317]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket NHTSA 99-5546]
RIN 2127-AH30


Federal Motor Vehicle Safety Standards: Light Vehicle Brake 
Systems

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Withdrawal of rulemaking.

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SUMMARY: This action withdraws a rulemaking action initiated with the 
issuance of a proposal in 1996. In that proposal, NHTSA proposed to 
extend the requirements of the passenger car brake system standard to 
trucks, buses, and multipurpose passenger vehicles with a gross vehicle 
weight rating (GVWR) of 4,536 kilograms (10,000 pounds) or less. In a 
1997 final rule, NHTSA extended the passenger car brake requirements to 
trucks, buses, and multipurpose passenger vehicles with GVWRs of 3,500 
kilograms (7,716 pounds) or less. At that time, the agency deferred its 
decision on the issue of whether to include vehicles with GVWRs between 
3,501 kilograms and 4,536 kilograms.
    NHTSA believes that the limited safety benefit that could be 
derived from requiring these vehicles to comply with Standard No. 135 
would not be justified by the considerable costs and burden of 
redesigning their brake systems. In response to comments by the vehicle 
manufacturers about the proposal, NHTSA conducted the passenger car 
brake sequence tests on four late-model vehicles with GVWRs between 
3,501 kilograms and 4,536 kilograms. All vehicles were tested to the 
hydraulic brake standard, which specifies performance standards for 
hydraulic braking systems on hydraulically-braked vehicles with a GVWR 
greater than 3,500 kilograms (7,716 pounds). All of the tested vehicles 
failed some aspect(s) of the test sequence, tending to confirm 
manufacturers' assertions that redesign of the braking systems of 
vehicles in this category may be necessary to meet the passenger car 
brake standard. Accordingly, NHTSA is withdrawing the rulemaking action 
initiated in 1996.

FOR FURTHER INFORMATION CONTACT: For technical issues: Mr. Samuel 
Daniel, Jr., Safety Standards Engineer, Office of Crash Avoidance 
Standards, Vehicle Dynamics Division, 400 Seventh Street, SW, room 
5307, Washington, DC 20590; telephone (202) 366-2720; fax (202) 493-
2739.
    For legal issues: Mr. Walter Myers, Attorney-Advisor, Office of the 
Chief Counsel, National Highway Traffic Safety Administration, 400 
Seventh Street, SW, room 5219, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

A. Background

(1) Rulemaking History

    In order to harmonize U.S. brake standards with international brake 
standards, NHTSA published a final rule on February 2, 1995, 
establishing a new Federal Motor Vehicle Safety Standard (Standard) No. 
135, Passenger car brake systems (60 FR 6411).1 This new 
standard replaced Standard No. 105, Hydraulic brake systems, insofar as 
Standard No. 105 applied to passenger cars.
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    \1\ This standard was subsequently renamed Light Vehicle Brake 
Systems.
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    On May 2, 1996, NHTSA published a Notice of Proposed Rulemaking 
(NPRM) proposing to extend the applicability of Standard No. 135 to all 
multipurpose passenger vehicles, trucks, and buses with GVWRs of 4,536 
kilograms (kg) (10,000 pounds (lbs)) or less (61 FR 19602) (hereinafter 
referred to as ``LTVs,'' meaning light trucks and vans). The agency 
stated in the NPRM that the extension of the provisions of Standard No. 
135 to LTVs would be consistent with the agency's policy of achieving 
international harmonization wherever possible and consistent with the 
agency's statutory mandate to increase motor vehicle safety in the U.S.
    NHTSA received 8 comments in response to the NPRM, 5 from vehicle 
manufacturers, 2 from vehicle trade

[[Page 20246]]

associations, and 1 from a safety advocacy group. Most of the vehicle 
manufacturers and the American Automobile Manufacturers Association 
commented that compliance with Standard No. 135 may require major 
modification of the brake systems of vehicles with GVWRs above 3,629 kg 
(8,000 lbs). They asserted that brake performance requirements in 
Standard No. 135 are more stringent than those in Standard No. 105. 
They argued that, because of the heavier weight range of these 
vehicles, they may not be able to meet the requirements of Standard No. 
135 without substantial brake system redesign. They further commented 
that brake systems on vehicles with GVWRs greater than 8,000 lbs may 
have undesirable consumer characteristics such as increased noise, 
wear, and pedal travel if required to meet Standard No. 135 
requirements.
    In response to those comments, NHTSA decided to extend the 
applicability of Standard No. 135 only to those with GVWRs of 3,500 kg 
(7,716 lbs) or less, and reserved for possible later action the issue 
of whether to further extend those requirements to LTVs with GVWRs 
between 3,501 kg and 4,536 kg. Consequently, on September 30, 1997, 
NHTSA published a final rule in the Federal Register extending the 
provisions of Standard No. 135 to trucks, buses, and multipurpose 
passenger vehicles with GVWRs of 3,500 kg (7,716 lbs) or less, 
effective December 1, 1997, and becoming mandatory for these vehicles 
beginning September 1, 2002 (62 FR 51064). The agency stated, however, 
that the issue of extending the applicability of Standard No. 135 to 
vehicles with GVWRs between 3,501 kg (7,716 lbs) and 4,536 kg (10,000 
lbs) would be separately addressed after reviewing brake test data 
submitted by Ford Motor Company (Ford) and the agency's own testing and 
analysis of vehicles in this weight range.

(2) Harmonization Considerations

    The European equivalent of Standard No. 135 is ECE R13-H, which is 
applicable to passenger vehicles with a maximum seating capacity of 
nine. This category of vehicles is designated as the ``M1'' category. 
Although this category of vehicles has no weight classification, the 
weight of such vehicles rarely exceeds 3,175 kg (7,000 lbs). NHTSA's 
proposal to extend the applicability of Standard No. 135 to vehicles 
with GVWRs of 4,536 kg (10,000 lbs) or less would have extended the 
applicability of Standard No. 135 to vehicles in as many as 4 European 
vehicle classes not covered by R13-H, such as categories M2, M3, N2, 
and N3. In the interest of maintaining harmonization as nearly as 
possible with European standards, however, the agency believed 3,500 kg 
(7,716 lbs) rather than 3,629 kg (8,000 lbs) to be the logical 
breakpoint for the applicability of Standard No. 135 since this value 
is also used in the European system as the maximum GVWR for the ``N1'' 
category, which designates light non-passenger vehicles.

(3) Test Data

    Because of the comments of vehicle manufacturers that some of their 
vehicles between 3,629 kg (8,000 lbs) and 4,536 kg (10,000 lbs) would 
not be able to comply with all the requirements of Standard No. 135, 
NHTSA conducted the current brake test sequence of Standard No. 135 on 
4 late-model domestic trucks and vans in that GVWR range at the 
agency's Vehicle Research and Test Center (VRTC). Two pickup trucks and 
2 full-size vans were leased for the testing. All had front disc and 
rear drum brakes, fixed proportioning valves, and front/rear hydraulic 
circuit splits. Two were equipped with rear-axle-only antilock brake 
systems (ABS), while the other two were equipped with 4-wheel ABS. The 
vehicles were instrumented as necessary to perform the Standard No. 135 
test sequence, excluding the torque wheel portion of the sequence. 
Additional stops were made for certain portions of the test using a 
700-Newton (N) pedal force in the cold effectiveness, engine off, 
hydraulic circuit failure, and failed power assist tests. These higher 
pedal force stops were made to collect data on stopping capability in 
response to the NPRM comments of some vehicle manufacturers. These 
additional stops were made only if there had been no wheel lockup 
during stops utilizing the currently-prescribed 500-N pedal force. Had 
there been wheel lockup with a pedal force of 500 N, higher pedal 
forces would not have improved the stopping performance of the vehicles 
concerned. The test report, entitled ``Extension of FMVSS No. 135 to 
8000-10,000 Pound Vehicles,'' has been placed in the agency's docket 
(Docket 85-06, Notice 13-001).
    The tests confirmed that extending the current requirements of 
Standard No. 135 to vehicles in the 3,629 kg (8,000 lbs) to 4,536 kg 
(10,000 lbs) weight range would pose compliance problems for them 
unless their brake systems were modified, possibly extensively. NHTSA 
found that the tested vehicles were unable to achieve the specified 
passenger car brake performance level in a number of the test sections. 
The failed hydraulic circuit tests, S7.10 (front circuit), resulted in 
three of the four vehicles failing to meet the requirements for the 
lightly loaded condition, a stopping distance of 168 m from a speed of 
100 km/h. The Ford E-350 stopped in approximately 210 m, the Ford F-350 
stopped in approximately 280 m, and the Dodge Ram 2500 stopped in 
approximately 195 m.
    The brake power assist unit inoperative test, S7.11, resulted in 
all four vehicles failing to meet the requirement of a 168 m stopping 
distance from a speed of 100 km/h with a maximum pedal force of 500 N. 
Both the Dodge Ram and the GM G30 had a stopping distance of over 300 m 
when tested with a maximum pedal force of 500 N. When tested with a 
pedal force of 700 N, the Dodge Ram had a stopping distance of 
approximately 280 m, and the GM G30 had a stopping distance of 
approximately 220 m. The remaining two vehicles passed the test with 
the 700 N pedal force allowance.
    None of the vehicles passed all parts of the hot performance and 
recovery performance tests, S7.14 and S7.16, respectively. The 
performance requirements in S7.14 (first stop) and S7.16 are calculated 
for each vehicle based on its measured stopping distance and its 
average deceleration achieved during the shortest cold effectiveness 
stop in S7.5, Cold Effectiveness. With regard to the first of two hot 
stops required, the Ford F-350 stopped in a distance of approximately 
116 m, thereby exceeding the required stopping distance of 104 m. The 
Dodge Ram stopped in approximately 118 m, exceeding the required 
stopping distance for the vehicle of 100 m. In the second hot 
performance stop, the Ford F-350, the Dodge Ram, and the GM G30 failed 
to meet the 89 m stopping requirement with a maximum pedal force of 500 
N. The F-350 required approximately 115 m, the Ram required 
approximately 105 m, and the G30 required approximately 99 m to stop 
from 100 km/h. At a 700 N maximum pedal force allowance, the Dodge Ram 
and the GM G30 both failed the 89 m requirement, with the Ram requiring 
approximately 104 m, and the G30 requiring approximately 93 m to stop 
from 100 km/h.
    The Dodge Ram was the only vehicle to fail the recovery test (upper 
limit) with both a 500 N and a 700 N pedal force limit. At 500 N, the 
Ram required approximately 102 m to stop from a speed of 100 km/h and 
this vehicle required approximately 100 m to stop with the 700 N pedal 
force limit thereby exceeding the required stopping distance of 86 m. 
The Ford F-350 failed

[[Page 20247]]

the recovery test when tested with the 500 N pedal force limit, with a 
stopping distance of 93 m, exceeding the maximum allowable distance of 
91 m. At a maximum pedal force of 700 N, the F-350 stopping distance 
was approximately 83 m, passing the recovery test requirements. The 
Ford E-350 and the GM G30 met the stopping distance requirements for 
the recovery test at both 500 N and 700 N maximum pedal force.

B. Discussion

    In the September 30, 1997 final rule, the agency estimated annual 
sales of LTVs with GVWRs between 3,500 kg (7,716 lbs) and 4,536 kg 
(10,000 lbs) to be 0.5 to 0.7 million, or about 10 to 13 percent of all 
LTVs sold with GVWRs less than 4,536 kg (10,000 lbs). The agency stated 
that, based on such a low production volume, brake system redesign for 
such vehicles without sufficient leadtime could be particularly 
burdensome. Based on the FMVSS No. 135 performance tests failed by 
these vehicles, it is apparent that several brake sub-systems would 
need modification to meet all the requirements of the standard. The 
failure to meet the requirements of the hydraulic circuit failure test, 
S7.10 (front circuit), indicates that more braking capacity is required 
by the front brakes or the circuits could be modified such that each 
circuit contains one front and one rear brake, a common design for 
passenger cars. In order to meet the brake power assist unit 
inoperative requirements, the braking capability of the foundation 
brake system would have to be improved, which would require larger 
surface areas for the friction components, larger force actuation 
components (calipers and wheel cylinders), or a modification to master 
cylinder to allow for lower pedal force. To meet the hot and recovery 
performance requirements, S7.14 and S7.16, additional heat venting of 
the primary braking components at each wheel, or larger components 
requiring less stress or pressure on force actuation and friction 
components would be required to reduce fade.
    Further, virtually all brake sub-systems on the vehicles tested 
would have to undergo some modification to meet all the FMVSS 135 
requirements, since their brake systems are not currently designed to 
meet the sub-system failure tests in the standard. As previously 
stated, the resulting brake systems could have undesirable consumer 
characteristics such as increased noise, wear, and pedal travel.
    Review of the National Automotive Sampling System (NASS) crash data 
for the calendar years 1995-1997 indicates that light trucks and vans 
(LTVs) with a GVWR below 4,536 kg (10,000 lbs.) were involved annually 
in about 1,018,130 crashes that resulted in non-serious injuries. From 
the same data base, LTVs with a GVWR between 3,500 and 4,536 kg (7,716 
and 10,000 lbs.) were involved annually in about 55,270 crashes that 
resulted in non-serious injuries, or about 5.4 percent of the total LTV 
non-serious crash experience. The total LTV population was involved 
annually in about 46,940 crashes that resulted in serious injuries, 
based on the NASS files. LTVs with a GVWR between 3,500 and 4,536 kg 
were involved in about 3,050 of these crashes, or about 6.5 percent of 
the total annual LTV crash experience in which serious injuries 
occurred. Regarding fatal crashes, data from the Fatality Analysis 
Reporting System (FARS) for the calendar year 1996 show that LTVs with 
a GVWR of 4,536 kg or less were involved in 11,035 crashes resulting in 
fatal injuries. LTVs with a GVWR between 3,500 and 4,536 kg were 
involved in 1,267 crashes that resulted in fatality in 1996, or about 
11.5 percent of the total fatalities involving LTVs that year. The NASS 
data for 1995-1997 were also queried for evidence of brake performance 
problems that could be obtained from the crash experience data. The 
data indicate that braking was an LTV crash avoidance action in about 
26.7 percent of tow away crashes involving LTVs with a GVWR of 4,536 kg 
or less. For LTVs with a GVWR between 3,500 and 4,536 kg, braking was 
an LTV crash avoidance action in about 21.8 percent of the tow away 
crashes. Braking was an LTV crash avoidance action in about 8.6 percent 
of crashes resulting in fatality, according to the 1996 FARS, while LTV 
braking was a crash avoidance action in about 12.2 percent of the fatal 
crashes involving with LTV in the 3,500 to 4,536 kg range.
    The agency estimates that LTVs with a GVWR between 3,500 and 4,536 
kg constitute about 10-13 percent of all registered LTVs, which is 
consistent with their annual production and sales figures in the recent 
past. The market share of LTVs has increased dramatically over the past 
five years when compared to the increase in total production of 
vehicles with a GVWR of 4,536 kg or less. However, the vast majority of 
the vehicles that are penetrating the passenger cars market are light 
trucks and vans with a GVWR under 3,500 kg, which are being driven as 
an alternative to passenger cars. Vehicles with a GVWR between 3,500 
and 4,536 kg are primarily commercial vehicles, vans and pick-up trucks 
driven mostly by business organizations to deliver goods and services 
during business hours. The crash data and crash avoidance action data 
show that these vehicles are under represented in terms of crash 
frequency when compared to their portion of the LTV population. The 
fatal crash frequency for these vehicles is consistent with their 
estimated numbers as a percentage of the LTV population, as is the 
frequency in which braking is reported as a crash avoidance action. 
These data strongly indicate that there are no inordinate crash or 
braking problems associated with LTVs in the 3,500 to 4,536 kg weight 
range.
    Although specific manufacturer design strategies are not known to 
the agency, and resulting costs cannot be precisely quantified, the 
agency believes that the potential safety benefits of modifying 
vehicles in the 3,500 to 4,536 kg weight range to meet the requirements 
of Standard No. 135 are not substantial enough to justify the expected 
costs of these modifications. As previously stated, vehicles in this 
weight range are estimated to represent about 10 to 13 percent of all 
trucks and vans with a GVWR below 10,000 lbs. Sport utility and 
passenger vehicles in this weight range, such as the Chevy Suburban are 
estimated to represent a small portion of the total vehicles in this 
weight range.
    The two regulatory options available in selecting the appropriate 
brake system standard for vehicles in this weight range are: (1) 
keeping them in Standard No. 105, or (2) further extending the 
applicability of Standard No. 135 to include them. Keeping them under 
Standard No. 105 appears to be the more appropriate option, given that 
Standard No. 135 was originally developed to harmonize passenger car 
braking standards with vehicles under the ECE regulations for light 
passenger vehicles, which are in the M1 category. Even if Standard No. 
135 is modified to permit a brake pedal force of 700 N, this would not 
improve sufficiently the performance of many of the vehicles in the 
3,500-4,536 kg weight range to bring them into compliance with many of 
the stopping distance requirements in Standard No. 135. Standard No. 
105 allows stopping distance requirements for vehicles with a GVWR 
between 3,500 and 4,536 kg in this weight range which are slightly 
longer than the distance allowed for smaller vehicles. Standard No. 135 
specifies wheel lock sequence performance to address directional 
stability during braking, while Standard No. 105 has no similar 
requirements. On the other hand, the

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pre-burnish test, the water test, and the dynamic emergency brake test 
of Standard No. 105 are not included in Standard No. 135.

C. Agency Decision

    NHTSA has decided that Standard No. 105 should continue to apply to 
vehicles with GVWRs between 3,501 kg (7,716 lbs.) and 4,536 kg (10,000 
lbs.) for continuity with current requirements. Continuing to require 
vehicles with a GVWR above 3,500 kg (7,716 lbs.) to comply with 
Standard No. 105 would provide most of the safety benefits of Standard 
No. 135, while eliminating the need for possibly significant brake 
system redesign if such vehicles were required to comply with Standard 
No. 135. NHTSA believes that, given the relatively low sales volume of 
these vehicles, redesign of their brake systems would be particularly 
burdensome and any safety benefits would be limited.
    In addition, extending Standard No. 135 to vehicles in the 3,501-
4,536 kg weight category would unnecessarily move the standard away 
from harmonization with its European counterpart, ECE R13-H. Standard 
No. 135 was established in the first instance pursuant to NHTSA's 
ongoing efforts to harmonize its passenger car braking standards with 
international standards, consistent with the agency's statutory mandate 
to increase motor vehicle safety. By continuing to align the vehicle 
applicability of Standard No. 135 with the ECE categories M1 and N1, 
the agency will ensure that future harmonization efforts will be easier 
to implement. The vehicles to which Standard No. 135 apply will 
continue to be equivalent to the vehicles covered by ECE categories M1 
and N1. Standard No. 105 will continue to apply to trucks, buses, and 
multipurpose passenger vehicles, the equivalent to ECE categories M2, 
M3, N2, and N3. NHTSA believes, therefore, that alignment of its 
standards in that way will facilitate the implementation of future 
harmonization efforts.
    In view of the above, the agency withdraws the rulemaking action 
that it initiated in its May 1996 NPRM.

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

    Issued on April 20, 1999.
Ricardo Martinez,
Administrator.
[FR Doc. 99-10317 Filed 4-23-99; 8:45 am]
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