Interpretation ID: 1985-04.19

TYPE: INTERPRETATION-NHTSA

DATE: 11/12/85

FROM: ERIKA Z. JONES -- NHTSA CHIEF COUNSEL

TO: LARRY HIROHATA -- VEHICLE EQUIPMENT SAFETY SPECIALIST DEPARTMENT OF TRANSPORTATION MOTOR VEHICLE SAFETY OFFICE HONOLULU, HAWAII

TITLE: NONE

ATTACHMT: LETTER DATED 08/09/85 FROM JOHN LOVSTEDT TO JERE MEDLIN -- NHTSA

TEXT: Dear Mr. Hirohata:

This is in reply to the letter of August 9, 1985, from John Lovetedt, Highway Safety Manager, to Mr. Jere Medlin of this agency asking for a clarification of paragraph S4.5.11(c) of Federal Motor Vehicle Safety Standard No. 108, published in the Federal Register on July 22, 1985.

This paragraph (a renumbering of a paragraph in effect since January 1, 1972) states that "means may be provided to flash headlamps and side marker lamps for signaling purposes." Mr. Lovstedt asked whether this meant that a headlamp could be wired to operate as a turn signal lamp. On the basis of a specific prohibition in regulations of the Bureau of Motor Carrier Safety against combining a headlamp and a turn signal lamp, he concluded that headlamps should not be so wired.

This conclusion is correct. We believe that confusion could result from such a configuration given the relatively minor light output of a turn signal lamp compared with that of a headlamp. The provision is intended to allow cycles of activation and deactivation by automotic means of headlamps on police and emergency vehicles.

If you have any further questions, please let me know.

Sincerely,