Federal Motor Vehicle Safety Standards; Withdrawal of Proposed Rule, Announcement of Technical Workshop on Accelerator Control Systems

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. 95-93, Notice 3]

RIN 2127-AF76

Federal Motor Vehicle Safety Standards; Withdrawal of Proposed

Rule, Announcement of Technical Workshop on Accelerator Control Systems

AGENCY: National Highway Traffic Safety Administration (NHTSA),

Department of Transportation.

ACTION: Withdrawal of notice of proposed rulemaking, and announcement

of a technical workshop.

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SUMMARY: In this document, NHTSA withdraws a proposal to amend the

safety standard on accelerator control systems that would have deleted

a provision that specifies return-to-idle times for a normally

operating accelerator control system. The proposal was part of NHTSA's

efforts to implement the President's Regulatory Reinvention Initiative.

NHTSA has decided to withdraw its proposal in order to focus on the

broader issue of making the accelerator control system standard more

relevant for electronic accelerator systems. NHTSA announces a

technical workshop, tentatively scheduled for March 24, 1997, to

discuss electronic accelerator control technology and potential methods

of assuring fail-safe performance.

DATES: Technical workshop: The technical workshop is tentatively

scheduled for March 24, 1997. Those persons wishing to participate in

the workshop should contact Mr. Patrick Boyd (at the address given

below) not later than March 24, 1997.

Written comments. Written comments on the subject matter of the

workshop are due April 24, 1997.

ADDRESSES: The technical workshop will be held at the U.S. Department

of Transportation building, 400 Seventh Street, SW., Washington, DC. A

notice announcing the room number, and confirming the workshop date,

will be published shortly after the deadline for the public to advise

the agency of their intent to participate.

Written comments. Written comments concerning the subject matter of

the technical workshop should refer to the docket number and notice

number cited at the beginning of this notice, and be submitted to:

Docket Section, Room 5109, 400 Seventh Street, SW., Washington, DC

20590 (Docket hours are from 9:30 a.m. to 4 p.m.) It is requested, but

not required, that 10 copies of the comment be provided.

FOR FURTHER INFORMATION CONTACT: For technical issues: Mr. Patrick

Boyd, Office of Crash Avoidance Standards, NPS-21, telephone (202) 366-

6346.

For legal issues: Ms. Dorothy Nakama, Office of Chief Counsel, NCC-

20, (202) 366-2992.

Both may be reached at the National Highway Traffic Safety

Administration, 400 Seventh St., SW., Washington, DC, 20590. Comments

should not be sent to these persons, but should be mailed to the Docket

Section.

SUPPLEMENTARY INFORMATION:

President's Regulatory Reinvention Initiative

Pursuant to the President's March 4, 1995 directive, ``Regulatory

Reinvention Initiative,'' to the heads of departments and agencies,

NHTSA undertook a review of all its regulations and directives. During

the course of this review, the agency identified rules that it could

propose to eliminate as unnecessary or to amend to improve their

comprehensibility, application or appropriateness. As described below,

NHTSA identified Federal Motor Vehicle Safety Standard No. 124

Accelerator control systems (49 CFR 571.124) as one rule that might

benefit from being amended.

Background of Standard No. 124

Standard No. 124's purpose is to reduce deaths and injuries

resulting from loss of control of the engine speed of a moving vehicle

due to malfunctions in the vehicle's accelerator control system. Since

1972, Standard No. 124

[[Page 10515]]

has specified requirements for ensuring the return of a vehicle's

throttle to the idle position under each of the following two

circumstances: (1) When the driver removes the actuating force

(typically, the driver's foot or cruise control) from the accelerator

control, and (2) when there is a severance or disconnection in the

accelerator control system. Standard No. 124 applies to passenger cars,

multipurpose passenger vehicles, trucks, and buses.

Paragraph S5.1 of Standard No. 124 requires that, under any load

condition, and within the time specified in S5.3, the throttle must

return to the idle position from any accelerator position or any speed

of which the engine is capable, whenever the driver removes the

actuating force. The standard defines the throttle as ``the component

of the fuel metering device that connects to the driver-operated

accelerator control system and that by input from the driver-operated

accelerator control system controls the engine speed.''

Standard No. 124 has two further requirements to provide safety in

the event of accelerator control failure. The first, specified at S5.1,

requires ``at least two sources of energy,'' each capable of returning

the throttle to idle position within the time limit for normal

operation, from any accelerator position or speed whenever the driver

removes the opposing actuating force. The second, specified at S5.2,

requires that the throttle return to idle ``whenever any one component

of the accelerator control system is disconnected or severed at a

single point'' and the driver releases the pedal.

Paragraph S5.3 requires that the throttle return to idle within 1

second for vehicles of 4536 kilograms or less gross vehicle weight

rating (GVWR) and within 2 seconds for vehicles with a GVWR greater

than 4536. The maximum allowable time is increased to 3 seconds for any

vehicle that is exposed to ambient air at -18 degrees to -40 degrees

Celsius during the test or for any portion of a 12 hour conditioning

period.

Prior Request for Comments and Public Response

The agency published a request for comments (60 FR 62061) on

December 4, 1995 to initiate a discussion of the accelerator control

issues frequently raised by manufacturers in requests for

interpretation.

The questions involved two aspects of the standard: The return-to-

idle requirement and the single-point failure requirement. In their

requests for interpretation, manufacturers had sought assurance that

the presence of controls that lock the engine speed above the idle

level to facilitate the use of auxiliary equipment for dumping, mixing,

compacting, etc. would not be considered violations of the return-to-

idle timing requirements. Manufacturers had similar concerns about the

degree of repeatability of idle speed necessary for compliance with the

return-to-idle provisions. Some manufacturers were concerned that since

the speed to which a vehicle returns may vary from one occasion to the

next, the agency might regard speeds at the high end of the range of

normal variations of idle speeds as a violation of the return-to-idle

requirement. The agency requested comment on these issues to determine

whether it should amend the standard to eliminate concern that the

normal operation of accelerator controls could be confused with

instances of failure.

The second aspect of concern arises from the emerging technology of

electronic accelerator control systems. The agency had received

requests for interpretation expressing the belief that electronic

accelerator control systems were not subject to the requirement that

the engine return to idle in the event of a single point disconnection

or severance of the system. Although NHTSA had written a letter to

Isuzu in 1988 confirming that the single-point failure requirement

applies to both electronic and mechanical accelerator controls, the

agency requested comments on the need for language in the standard to

clarify how the requirement applies to electronic accelerator controls.

In the request for comments, NHTSA discussed clarifying the

existing standard's language with specific performance requirements for

enumerated types of disconnections and severances of mechanical and

electronic accelerator controls. Most auto industry commenters voiced a

preference for rescinding the standard, suggesting that market forces

would assure safety without the need for Standard No. 124. However,

they commented that, should the agency disagree about recision, a

standard specifying fail-safe performance in the least design-specific

terms would be preferable to the solution suggested in the notice.

Industry commenters expressed a desire to participate in a public

technical meeting with NHTSA concerning electronic accelerator controls

and potential regulatory language regarding fail-safe performance.

Notice of Proposed Rulemaking

NHTSA tentatively agreed with the commenters that market forces are

likely to prevent the introduction of accelerator controls whose normal

mode of operation is a threat to safety, but it disagreed that market

forces would necessarily assure adequate fail-safe performance.

Consequently, in a notice published on April 30, 1996 (61 FR 19020),

NHTSA proposed to eliminate section S5.3, which contains the return-to-

idle timing tests for the normal operation of accelerator controls. As

a rationale for the proposed removal of S5.3, NHTSA pointed out that

its standards compliance test program has revealed no noncompliances

with S5.3 for at least the past eight years. NHTSA stated that with the

elimination of S5.3, Standard No. 124 would be concerned solely with

fail-safe requirements for engine controls. An effort to define idle

speed tolerances and the normal operation of controls for operating

special equipment would no longer be necessary.

NHTSA further stated its belief that the market force argument

cannot be made for the fail-safe performance of accelerator controls.

The normal operating characteristics of a vehicle's accelerator control

system are immediately and constantly apparent to the buyer and user.

An unsatisfactory design would be met with criticism and rejection.

However, the vehicle owner has no easy way to experience directly the

consequences of severances of the control circuits on loss of engine

control and little motivation to do so.

Public Comments on the NPRM

In response to the NPRM, NHTSA received comments from the Advocates

for Highway and Auto Safety (Advocates), Allied Signal Inc., Chrysler,

General Motors, Mr. Honore J. Lartigue, and Volkswagen. Industry

comments to the NPRM were positive but perfunctory. Chrysler and Allied

Signal pointed out that the return-to-idle time required for partially

disabled systems by the retained fail-safe performance requirements

would be no different than the normal operation requirements for trucks

proposed for elimination. Advocates for Highway and Auto Safety

characterized the proposal as an abuse of agency discretion. It

criticized NHTSA's tentative opinion of the lack of need for

requirements for the normal operation of accelerator controls as

unsupported with appeals to specific data, studies, or other evidence.

1

Generally, the industry commenters expressed more interest in the

electronic accelerator control issues, which were not the specific

subject of the NPRM, than in the proposed elimination of S5.3. Allied

Signal, Volkswagen and General Motors cited the difficulty of applying

the language of the current

[[Page 10516]]

standard to electronic accelerator controls, including even the basic

terms ``throttle'' and ``idle position.'' General Motors'' comment

dismissed the proposal as unimportant and instead presented useful

ideas about fail-safe provisions it considered applicable to electronic

accelerator controls. It stated that with electronic engine controls,

throttle position is no longer the singular factor that controls engine

speed. It is possible to exploit control of spark advance and/or fuel

metering as alternative means of preventing uncontrolled engine speed.

Therefore, General Motors suggested that the present requirement of two

sources of energy to return the throttle to the idle position be

replaced by a more general requirement of two means capable of

returning the engine to idle in the event of the disconnection or

severance of the other. It also suggested a second provision that if

two means of returning the engine to idle cannot be provided, then a

fail-safe feature would either shut-down the engine or automatically

shift the transmission into neutral in the event of a disconnection or

severance of the accelerator control.

General Motors' suggestions invite questions about their

applicability to diesel engines and about the desirability of shifting

the transmission into neutral, but they represent constructive thought

about the preservation of fail-safe performance in the face of changing

technology for accelerator control.

Agency Withdrawal of NPRM

After carefully reviewing the public comments, NHTSA has decided to

withdraw its proposal to remove S5.3 from Standard No. 124. The public

commenters addressing the issue have highlighted the fact that there

are many unresolved areas involving electronic accelerator controls.

NHTSA is withdrawing the proposal so that it can fully review the issue

of making the standard more relevant to electronic systems prior to

considering any other amendments to the Standard.

Technical Workshop

As stated in its December 4, 1995 request for comments (60 FR

62061), NHTSA plans to hold a technical workshop on the need to amend

Standard No. 124. NHTSA tentatively plans to hold the workshop on March

24, 1997, at the U.S. Department of Transportation Building (400

Seventh Street, SW.) in Washington, DC. NHTSA believes its long range

plans for Standard No. 124 will be facilitated if workshop participants

and submitters of written comments discuss the questions raised in the

December 1995 request for comments.

The agency wishes workshop participants to discuss:

(1) The principles of operation of existing and potential

electronic accelerator control systems for gasoline and diesel engines;

(2) The principles of operation of existing and potential means of

providing fail-safe performance in the event of loss of accelerator

control by the primary system; and

(3) Suggestions for regulatory requirements that will assure the

fail-safe performance of electronic accelerator control systems.

The agency therefore asks those persons interested in participating

to make their interest known by contacting Mr. Boyd, and describing the

topic(s) the person wishes to address. Although NHTSA expects to hold

the technical workshop in March 1997, it would appreciate being

informed if any interested persons need more time to prepare remarks.

If many people state that more time is necessary, NHTSA will pick a

later date. The two persons mentioned at the beginning of this

termination notice are available to answer questions.

NHTSA will issue another notice announcing the room number of the

workshop and agenda items to be discussed. If necessary, the date for

the workshop and submission of written comments will be adjusted.

Accordingly, as discussed in the preamble, the notice of proposed

rulemaking published in the Federal Register on April 30, 1996 (61 FR

19020) is withdrawn.

Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;

delegations of authority at 49 CFR 1.50 and 501.8.

Issued on: March 4, 1997.

L. Robert Shelton,

Associate Administrator for Safety Performance Standards.

[FR Doc. 97-5727 Filed 3-6-97; 8:45 am]

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