[Federal Register Volume 61, Number 33 (Friday, February 16, 1996)]
[Rules and Regulations]
[Pages 6173-6175]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3258]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 90-3; Notice 6]
RIN 2127-AF63
Federal Motor Vehicle Safety Standards; Air Brake Systems; Air
Compressor Cut-In
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Final rule.
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SUMMARY: This document concludes a rulemaking proceeding begun in
response to a petition for rulemaking submitted by the Truck Trailer
Manufacturers Association (TTMA). It amends Standard No. 121, Air Brake
Systems, to require the automatic activation of the air compressor on a
powered vehicle whenever the pressure in the air brake system drops
below 100 pounds per square inch (psi). The agency has concluded that
the amendment will ensure that new truck tractors provide trailers with
sufficient air pressure for release of the trailer parking brakes and
provide adequate service braking. In addition, the amendment will
provide greater air reserves on all air braked vehicles.
DATES: Effective date. The amendment becomes effective March 18, 1996.
Compliance date. Compliance with the amendment will be required on and
after March 1, 1997.
Petitions for reconsideration. Any petitions for reconsideration of
this rule must be received by NHTSA no later than April 1, 1996.
ADDRESSES: Petitions for reconsideration of this rule should refer to
the above referenced docket numbers and should be submitted to:
Administrator, National Highway Traffic Safety Administration, 400
Seventh Street SW., Washington, D.C. 20590.
FOR FURTHER INFORMATION CONTACT:
For non-legal issues: Mr. Richard Carter, Office of Crash
Avoidance, National Highway Traffic Safety Administration, 400 Seventh
Street, SW., Washington, D.C. 20590 (202) 366-5274.
For legal issues: Mr. Marvin L. Shaw, NCC-20, Rulemaking Division,
Office of Chief Counsel, National Highway Traffic Safety
Administration, 400 Seventh Street, SW., Washington, D.C. 20590 (202-
366-2992).
SUPPLEMENTARY INFORMATION:
I. Background
Standard No. 121, Air Brake Systems, specifies performance and
equipment requirements for braking systems on vehicles equipped with
air brakes, including a requirement specifying the minimum air pressure
at which a towing vehicle's air compressor governor must automatically
activate the compressor. The governor maintains reservoir air pressure
between predetermined minimum and maximum pressures. Under the current
requirement in S5.1.1.1, the governor must automatically activate the
air compressor when air pressure in the reservoir falls to 85 pounds
per square inch (psi). Currently manufactured air brake systems
typically operate between 100 psi and 120 psi.
NHTSA adopted the air compressor governor minimum cut-in
requirement on October 8, 1991. (56 FR 50666) In adopting the
requirement, the agency explained that the requirement will ensure, in
the event of an air leak in a tractor's brake supply system, the air
compressor for the system will be activated to restore or maintain
pressure in the system until the air leak is detected and corrected.
The agency further stated that since most vehicles already complied
with the cut-in requirement, it would not result in an undue burden for
manufacturers.
The October 1991 final rule also amended Standard No. 121 by
deleting the requirement for each trailer to have a separate protected
reservoir for the purpose of releasing the parking brake. Under the
rule, air pressure from the tractor supply lines may be used to
[[Page 6174]]
release the trailer parking brakes instead of air from a separate
reservoir. The final rule also specified requirements for a minimum air
pressure of 70 psi in the trailer's supply line in the event of
pneumatic failure. The final rule also prevents the automatic
application of the trailer parking brakes while the minimum trailer
supply line air pressure is maintained.
II. Rulemaking Petition
On August 2, 1994, the Truck Trailer Manufacturers Association
(TTMA) submitted a petition for rulemaking to amend S5.1.1.1 of
Standard No. 121 to increase the minimum air pressure, at which the
governor is required to activate the air compressor, from 85 psi to 100
psi. The petitioner stated that its requested amendment is necessary to
assure that new truck tractors provide air braked trailers with
sufficient pressure for release of the trailer parking brakes and to
provide adequate service braking. TTMA said that the current 85 psi air
pressure compressor cut-in requirement may not be sufficient to ensure
that adequate pressure is supplied to a trailer being towed by a
tractor. TTMA also stated that higher truck or tractor air pressures
increase the speed at which trucks or tractors can resupply trailers
with air and that these higher pressures will store more air for use by
the braking systems. The petitioner further stated that ``all tractor
manufacturers are now building tractors whose nominal compressor cut-in
pressure is at least 100 psi.''
III. NHTSA Proposal
On June 13, 1995, NHTSA published a notice of proposed rulemaking
(NPRM) proposing to increase the required minimum air compressor cut-in
pressure from 85 psi to 100 psi. (60 FR 31135) The agency set forth the
following reasons for its decision to propose increasing the cut-in air
pressure above the current 85 psi level. First, the agency believed
that the proposed amendment would enhance safety by better ensuring
that new truck tractors are capable of providing trailers with
sufficient pressure for release of the trailer parking brakes and
provide adequate service braking. Specifically, raising the minimum
cut-in pressure would allow the storage of an additional volume of
compressed air that would be available for an air brake system. Second,
the agency stated that the proposal to maintain an overall higher
system air pressure would allow a better ``match up'' of protection
valve settings between the tractors and trailers. Third, the agency
stated that a greater margin of safety would be provided for long
stroke brake chambers, which need more compressed air.
After explaining its tentative conclusion that increasing the cut-
in pressure to 100 psi would not result in any safety problems, NHTSA
invited comments about whether the proposed amendment would affect
safety.
NHTSA further stated that its analysis of current manufacturing
practices confirmed TTMA's statement that manufacturers are typically
building vehicles with a cut-in pressure of at least 100 psi. The
docket includes a memorandum summarizing the agency's discussions with
vehicle manufacturers and the American Trucking Associations (ATA) in
which they indicate that new truck tractors are typically equipped with
governors that activate the air compressor when air pressure drops to
100 psi. In addition, Midland-Grau and Allied Signal, which together
produce over 95 percent of the air compressors and governors in the
United States, stated that they set their air compressors and governors
at 100 psi or higher. Based on its research, NHTSA was aware of no
company that manufactures these devices with a cut-in pressure between
85 and 100 psi nor of any purchaser that requests a cut-in pressure in
this lower range. Accordingly, NHTSA believed that the proposed
amendment would codify existing industry practice, since equipment on
new vehicles are being built with the proposed settings.
IV. Comments on the NPRM and Final Rule
NHTSA received comments from ATA, the Truck Manufacturing
Association (TMA), the Heavy Duty Brake Manufacturing Council (HDBMC),
the Truck Trailer Manufacturers Association (TTMA), the Advocates for
Highway Safety (Advocates), vehicle manufacturers (Ford, Mack Truck,
Navistar, and PACCAR), brake manufacturers (Allied Signal and Midland-
Grau), and an engineering consultant.
The commenters generally supported the proposal to raise the air
compressor cut-in pressure to 100 psi or more. Even though it did not
oppose the proposal, TMA stated that there was little need for adopting
the proposal since the vast majority of vehicles already meet the
proposed requirements and the rest will soon comply. That organization
expressed concern that while most domestic manufacturers already comply
with the cut-in requirements, new entries and imports may be designed
to the 85 psi requirement. However, NHTSA believes that in Europe, cut-
in pressure is typically over 100 psi. Should TMA have specific data on
this issue, it is encouraged to present it to the agency. TMA,
Navistar, AlliedSignal, Mack Trucks, and HDBMC requested that the
agency modify the wording to state that the cut-in pressure shall be
``100 psi or greater.'' These commenters believed that this modified
wording will accommodate variations in manufacturers' recommended cut-
in pressures.
Based on its review of the comments and the available information,
NHTSA has decided to amend Standard No. 121 to require the automatic
activation of the air compressor whenever the pressure in the air brake
system drops below 100 psi. As the agency stated in the NPRM, this
amendment will ensure that new truck tractors are capable of providing
trailers with sufficient pressure for release of the trailer parking
brakes and provide adequate service braking. Specifically, raising the
cut-in pressure allows the storage of an additional volume of
compressed air that will be available for an air brake system. Second,
requiring an overall higher system air pressure will allow a better
``match up'' of protection valve settings between the tractors and
trailers. Third, the amendment will provide a greater margin of safety
for long stroke brake chambers, which need more compressed air. The
agency anticipates no safety problems as the result of this amendment.
ATA commented that it had no objection to the proposal if it
applied only to towing trucks and tractors. However, that organization
opposed applying the proposal to single unit vehicles.
NHTSA has decided to apply the air compressor cut-in pressure
requirements to all powered vehicles, including single unit vehicles.
The agency believes that raising the air compressor cut-in pressure to
100 psi provides potential safety benefits in addition to providing
faster brake release times between the tractor and trailers and better
balancing of pressures. The agency has decided to include single unit
vehicles in the requirements because of its concern over increased air
consumption with long stroke brake chambers combined with ABS. The
agency is currently reviewing petitions for reconsideration on its rule
allowing long stroke brake chambers and, subsequent to its response,
encourages ATA and others to reexamine this issue. Even though ATA
stated that it was concerned that there may be some special
applications or vehicle types where a lower air pressure is desirable
or necessary, the agency is not aware of any specific examples of
[[Page 6175]]
any such special conditions that preclude the use of the higher air
pressure.
In the NPRM, NHTSA proposed that compliance date for the final rule
be 30 days after its publication in the Federal Register. The agency
stated that this amendment would have no adverse effect on
manufacturers since all manufacturers currently comply with the
proposed requirements. NHTSA requested comments about whether a
leadtime of 30 days would be appropriate or whether more lead time was
necessary.
Advocates favored a compliance date of 30 days after the notice's
publication. Mack requested that the compliance date not occur before
March 1, 1996, since that company manufactures two low volume truck
tractor models and a high volume truck model that require a longer
leadtime to convert to the higher cut-in pressure. PACCAR, commenting
through TMA, stated that it will need 12 months to adapt to the
proposed change.
NHTSA has decided to set a compliance date of March 1, l997 for the
amended air compressor cut-in pressure. The agency believes that
providing additional leadtime is necessary given that some
manufacturers will need additional time to modify certain vehicles.
Given that these manufacturers would have to make significant changes
to certain air brake systems, they would not be able to make the
modifications within the 30 day period that was initially proposed.
This compliance date also corresponds to that for the antilock brake
system and stopping distance requirements for truck tractors.
V. Rulemaking Analyses and Notices
1. Executive Order 12866 (Federal Regulatory Planning and Review) and
DOT Regulatory Policies and Procedures
This rulemaking was not reviewed under E.O. 12866. NHTSA has
analyzed this rulemaking and determined that it is not ``significant''
within the meaning of the Department of Transportation's regulatory
policies and procedures. A full regulatory evaluation is not required
because the rule will have a minimal effect on the costs or performance
of the existing air brake systems. For most manufacturers and most
vehicles, today's amendment merely codifies an existing industry
practice.
2. Regulatory Flexibility Act
In accordance with the Regulatory Flexibility Act, NHTSA has
evaluated the effects of this action on small entities. Based upon this
evaluation, I certify that the amendment will not have a significant
economic impact on a substantial number of small entities. Vehicle and
brake manufacturers typically do not qualify as small entities. Vehicle
manufacturers, small businesses, small organizations, and small
governmental units which purchase motor vehicles will not be
significantly affected by the requirements since the cost of new
vehicles will not change. Accordingly, no regulatory flexibility
analysis has been prepared.
3. Executive Order 12612 (Federalism)
This action has been analyzed in accordance with the principles and
criteria contained in Executive Order 12612, and it has been determined
that the rule will not have sufficient Federalism implications to
warrant preparation of a Federalism Assessment. No State laws will be
affected.
4. National Environmental Policy Act
Finally, the agency has considered the environmental implications
of this rule in accordance with the National Environmental Policy Act
of 1969 and determined that the rule will not significantly affect the
human environment.
5. Civil Justice Reform
This rule will not have any retroactive effect. Under section
103(d) of the National Traffic and Motor Vehicle Safety Act (49 U.S.C.
30111), 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 (49 U.S.C. 30161) 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.
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles, Reporting and
recordkeeping requirements, Rubber and rubber products, Tires.
In consideration of the foregoing, the agency is amending part 571
of Title 49 of the Code of Federal Regulations as follows:
PART 571--[AMENDED]
1. The authority citation for Part 571 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.50.
2. In Sec. 571.121, S5.1.1.1 is revised to read as follows:
Sec. 571.121 Standard No. 121; Air brake systems.
* * * * *
S5.1.1.1 Air compressor cut-in pressure. The air compressor
governor cut-in pressure shall be 100 p.s.i. or greater.
* * * * *
Issued on: February 8, 1996.
Ricardo Martinez,
Administrator.
[FR Doc. 96-3258 Filed 2-15-96; 8:45 am]
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