[Federal Register Volume 60, Number 113 (Tuesday, June 13, 1995)]
[Proposed Rules]
[Pages 31135-31137]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14461]



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DEPARTMENT OF TRANSPORTATION
49 CFR Part 571

[Docket No. 90-3; Notice 5]
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: Notice of proposed rulemaking (NPRM).

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SUMMARY: In response to a petition for rulemaking submitted by the 
Truck Trailer Manufacturers Association (TTMA), this notice proposes to 
amend the requirement for the minimum air compressor cut-in pressure in 
Standard No. 121, Air Brake Systems, to require the automatic 
activation of the air compressor whenever the pressure in the air brake 
system drops below 100 psi. The agency has tentatively concluded that 
the proposed amendment would ensure that new truck tractors provide 
trailers with sufficient air pressure for release of the trailer 
parking brakes and provide adequate service braking.

DATES: Comments. Comments must be received on or before August 14, 
1995.
    Proposed Effective Date. The proposed amendment in this notice 
would become effective 30 days after publication of a final rule in the 
Federal Register.

ADDRESSES: Comments should refer to the docket and notice numbers above 
and be submitted to: Docket Section, National Highway Traffic Safety 
Administration, 400 Seventh Street SW., Washington, DC 20590. Docket 
hours are 9:30 a.m. to 4 p.m., Monday through Friday.

FOR FURTHER INFORMATION CONTACT: Mr. Richard Carter, Office of Vehicle 
Safety Standards, National Highway Traffic Safety Administration, 400 
Seventh Street SW., Washington, DC 20590. (202-366-5274).

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 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 psi. 
Currently manufactured air brake systems typically operate between 100 
psi and 120 psi.
    NHTSA adopted the air compressor governor minimum cut-in 
requirement in S5.1.1.1 on October 8, 1991. (56 FR 50666) The agency 
explained that, under this requirement, the air compressor on a tractor 
will be activated to restore or maintain pressure in the brake supply 
system until the air leak is detected and corrected. The agency further 
stated that since most vehicles already comply with this requirement, 
it would not result in an undue burden for manufacturers.
    The October 1991 final rule also simplified requirements applicable 
to air brake systems by amending Standard No. 121 to delete 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 release the 
trailer parking brakes rather than air from a separate reservoir. The 
final rule also specified requirements for a minimum air pressure of 70 
p.s.i. in the trailer's supply line in the event of pneumatic failure 
and for prevention of 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 Standard No. 121 to 
increase the minimum air pressure governor cut-in requirement in 
S5.1.1.1 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 [[Page 31136]] pressure for 
release of the trailer parking brakes and to provide adequate service 
braking. TTMA said that the current 85 psi air pressure governor cut-in 
requirement may not supply adequate pressure 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 these higher pressures will store more air for 
use by the braking systems. It further stated that ``all tractor 
manufacturers are now building tractors whose nominal compressor cut-in 
pressure is at least 100 psi.''
III. NHTSA Proposal

    After reviewing TTMA's petition, NHTSA has decided to propose 
increasing the minimum air compressor cut-in pressure requirement from 
85 psi to 100 psi. There are several reasons for increasing the cut-in 
air pressure above the current 85 psi level. First, the agency has 
tentatively determined 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, by raising 
the cut-in pressure, this amendment would allow the storage of an 
additional volume of compressed air that would be available for an air 
brake system. This is important since the 1991 final rule eliminated 
the requirement for a separate protected reservoir with a stored volume 
of air used for releasing the trailer parking brakes. Second, 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, long stroke brake chambers, which need more 
compressed air, would have available an additional volume of air at 
higher pressure. This would provide a greater margin of safety.
    NHTSA has tentatively concluded that increasing the air pressure to 
a 100 psi minimum would not result in any safety problems. The agency 
invites comments about the effect of this proposed amendment on safety.
    NHTSA's analysis of current manufacturing practices confirms TTMA's 
statement that tractor manufacturers are now building tractors 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 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, NHTSA has 
discussed the issue of air pressure cut-in with Midland-Grau and 
AlliedSignal, which together produce over 95 percent of the air 
compressors and governors in the United States. Midland-Grau sets their 
air compressors and governors at 105 psi, while AlliedSignal sets their 
air compressors and governors at 100 psi. NHTSA knows of no company 
that manufactures these devices with a cut-on pressure between 85 and 
100 psi nor of any purchaser that requests a cut-on pressure in this 
lower range. Accordingly, NHTSA believes the proposed amendment would 
codify existing industry practice, since equipment on new vehicles are 
being built with the proposed settings.
    The statute requires that each order shall take effect no sooner 
than 180 days from the date the order is issued unless good cause is 
shown that an earlier effective date is in the public interest. NHTSA 
has tentatively concluded that there would be good cause not to provide 
the 180 day lead-in period given that this amendment will have no 
adverse effect on manufacturers since all manufacturers currently 
comply with the proposed requirements. Based on the above, the agency 
has tentatively concluded that there is good cause for an effective 
date 30 days after publication of the final rule. NHTSA requests 
comments about whether a 30 day effective date is appropriate or 
whether more lead time is necessary.

Rulemaking Analyses and Notices

1. Executive Order 12866 (Federal Regulatory Planning and Review) and 
DOT Regulatory Policies and Procedures

    This proposal was not reviewed under E.O. 12866. NHTSA has analyzed 
this proposal 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, if adopted, would have a minimal effect on costs or benefits of 
the existing requirements. In large part, today's proposed 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 proposed amendment would not have a 
significant economic impact on a substantial number of small entities. 
Vehicle and brake manufacturers typically would not qualify as small 
entities. Vehicle manufacturers, small businesses, small organizations, 
and small governmental units which purchase motor vehicles would not be 
significantly affected by the proposed requirements. 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 proposed rule would not have sufficient Federalism 
implications to warrant preparation of a Federalism Assessment. No 
State laws would be affected.

4. National Environmental Policy Act

    Finally, the agency has considered the environmental implications 
of this proposed rule in accordance with the National Environmental 
Policy Act of 1969 and determined that the proposed rule would not 
significantly affect the human environment.
5. Civil Justice Reform

    This proposed rule would 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.

Public Comments

    Interested persons are invited to submit comments on the proposal. 
It is requested but not required that 10 copies be submitted.
    All comments must not exceed 15 pages in length. (49 CFR 553.21). 
Necessary attachments may be appended to these submissions without 
regard to the 15-page limit. This limitation is intended to encourage 
commenters to detail their primary arguments in a concise fashion.
    If a commenter wishes to submit certain information under a claim 
of confidentiality, three copies of the complete submission, including 
purportedly confidential business information, should be submitted to 
the Chief Counsel, NHTSA, at the street [[Page 31137]] address given 
above, and seven copies from which the purportedly confidential 
information has been deleted should be submitted to the Docket Section. 
A request for confidentiality should be accompanied by a cover letter 
setting forth the information specified in the agency's confidential 
business information regulation. 49 CFR part 512.
    All comments received before the close of business on the comment 
closing date indicated above for the proposal will be considered, and 
will be available for examination in the docket at the above address 
both before and after that date. To the extent possible, comments filed 
after the closing date will also be considered. Comments received too 
late for consideration in regard to the final rule will be considered 
as suggestions for further rulemaking action. The NHTSA will continue 
to file relevant information as it becomes available in the docket 
after the closing date, and it is recommended that interested persons 
continue to examine the docket for new material.
    Those persons desiring to be notified upon receipt of their 
comments in the rules docket should enclose a self-addressed, stamped 
postcard in the envelope with their comments. Upon receiving the 
comments, the docket supervisor will return the postcard by mail.

List of Subjects in 49 CFR Part 571

    Imports, Incorporation by reference, Motor vehicle safety, Motor 
vehicles, Rubber and rubber products, Tires.

    In consideration of the foregoing, the agency proposes to amend 
Standard No. 121, Air Brake Systems, in Title 49 of the Code of Federal 
Regulations at Part 571 as follows:

PART 571--[AMENDED]

    1. The authority citation for Part 571 would be revised 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 would be 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 greater than 100 p.s.i.
* * * * *
    Issued on: June 8, 1995.
Barry Felrice,
Associate Administrator for Safety Performance Standards.
[FR Doc. 95-14461 Filed 6-12-95; 8:45 am]
BILLING CODE 4910-59-P