Interpretation ID: nht78-2.23

DATE: 06/30/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Pupil Transportation

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 9, 1978, asking whether a school bus manufacturer may install strobe lights on the top of vehicles as original equipment, without violating Federal Motor Vehicle Safety Standard No. 108. As you indicated in your letter of December 28, 1977, this would be permissible under local law.

I informed you on February 14, 1978, in requesting a clarification, that legality depended on whether the additional lighting impaired the effectiveness of the required equipment. If so, paragraph S4.1.3 of Standard No. 108 would prohibit installation. The lamps in question are strobe lights, either white or amber in color, that would be used during inclement weather. We do not know whether these lights would be used while the bus is in motion, or when it is stopped and the required schoolbus warning lamps are activated. If the strobe lights are used while the vehicle is in motion, during inclement weather, we do not know whether they would impair the effectiveness of the stop lamps by distracting the attention of a driver following the bus. If the light of the strobe lamp is white, and the light operates while the vehicle is at rest and its red or red and amber warning signals are also activated, the signals might prove confusing to other motorists. However, on the basis of the data presented, it is not possible to determine whether the strobe lamps would impair the effectiveness of the required lighting equipment within the meaning of S4.1.3. Therefore, we are willing to defer to the judgment of the State of Washington on this question, until such time, if ever, as data may be presented supporting a conclusion of impairment.

SINCERELY,

Superintendent of Public Instruction DR. FRANK B. BROUILLET

March 9, 1978

Joseph J. Levin, Jr. Chief Counsel U.S. DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration

Dear Mr. Levin:

In reply to your letter of February 14, 1978, it was our intent to request information about the use of strobe lights on school buses, as explained in the first sentence of my letter of December 28, 1977.

I am sorry that I did not notice the incorrect word used in the second paragraph, which made it sound like a stop light attached to the top of the buses.

In addition, your letter has asked for other information about "intended use of the strobe light". The intended color if used would be either amber or white, and it will not be located closely to any other clearance or other identification lamps. The strobe light nit itself has a lense size of approximately 3 to 4 inches. So far the information provided to this office does not rate strobe lights in terms of candle power output.

I trust that this is sufficient information for you to answer my earlier request about the legality of a manufacturer installing the strobe lights and delivering them to school districts upon the school districts' request.

DIVISION OF FINANCIAL SERVICES

Don M. Carnahan, Supervisor Pupil Transportation