Interpretation ID: 1984-1.50

TYPE: INTERPRETATION-NHTSA

DATE: 05/14/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Department of State Police; Commonwealth of Virginia

TITLE: FMVSS INTERPRETATION

TEXT:

U.S. Department of Transportation

National Highway Traffic Safety Administration

MAY 14 1984

B. R. Belsches, Captain Safety Officer Department of State Police Commonwealth of Virginia P.O. Box 27472 Richmond, Virginia 23261-7472

Dear Captain Belsches:

This is in response to your letter of April 20, 1984, asking for an interpretation of paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108 and "a history relative to the inclusion of such function of headlamps and marker lamps."

Paragraph S4.6(b) allows means to be provided for the automatic flashing of headlamps and side marker lamps for signaling purposes, as an exception to the general rule that vehicle lamps (other than turn and hazard warning signals, and school bus warning lamps) be steady-burning in use. This confirms your understanding of the wording of the standard and its effect. It does not allow, however,modulating headlamps which do not flash on and off, but deviate between a higher intensity end a lower one.

Originally, paragraph S3.5 of the standard (see e.g . 49 CFR 371.21, Standard No. 108 rev. as of January 1, 1970) stated that "normally steady-burning lamps may be capable of being flashed for signaling purposes." On January 3, 1970, the agency proposed paragraph S4.6 (35 F.R. 106) as it exists today. It was adopted on October 31, 1970 (35 F.R. 16840). The agency observed that some commenters requested that additional lamps be permitted to flash and some requested that flashing headlamps be prohibited. It also noted that, with the exceptions set forth in S4.6(a), flashing lamps should be reserved for emergency and road maintenance-type vehicles, and that flashing lamps are otherwise prohibited in the Uniform Vehicle Code. The agency further noted that lamps could be flashed by the driver merely by turning the switch on and off, and that itcould not prohibit that type of operation, but that the definition of "Flash," also adopted in the amendments, made clear that automatic flashers for use with steady-burning lamps other than headlamps and side marker lamps were prohibited.

This is the rulemaking history of paragraph S4.6. I hope that this will answer your questions.

Sincerely,

Frank Berndt Chief Counsel

COMMONWEALTH of VIRGINIA

DEPARTMENT OF STATE POLICE P.O.Box 2472, Richmond, Virginia 23261-7472

April 20, 1984

Mr. Frank Berndt Chief Counsel, NHTSA 400 Seventh Street, S.W. Washington, D. C. 20590

Dear Mr. Berndt:

In Virginia we prohibit flashing or modulating headlamps used for the purpose of emergency warning; however, there appears to be some conflict to this Virginia mandate in the Federal Motor Vehicle Safety Standards.

I refer to 49CFR (FMVSS), Part 571.108, Paragraph S4.6, Subparagraph b. From the wording in this paragraph, it appears that manufacturers are permitted to provide a means to flash headlamps and side marker lamps for signaling purposes.

Would you provide us an interpretation of this paragraph and, if possible, a history relative to the inclusion and benefit of such function of headlamps and marker lamps.

Sincerely,

B. R. Belsches, Captain Safety Officer (AC-804-323-2017)

BRB/kf