Federal Motor Vehicle Safety Standards; Air Brake Systems Air Compressor Cut-In

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