Interpretation ID: nht74-1.40

DATE: 02/19/74

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 15, 1974, asking whether a school bus rear lighting system is permissible that activates the back-up lamps and flashes four red stop lamps when the gearshift is in reverse.

The system of supplemental school bus warning lamps you describe is one that is not specified by Standard No. 108. Although S4.6(b) states that "All . . . lamps [other than those specified in S4.6(a)] shall be steady burning . . . ," we interpret this requirement as covering only the systems specified by the standard. Therefore there is no Federal prohibition against your installation of such a system. However, the system would be subject to regulation by the individual States, some of which may have restrictions on the use of flashing lights.

Yours truly,

ATTACH.

January 15, 1974

Richard Dyson -- Assistant Chief Counsel, U. S. Dept. of Transportation, NHTSA

Dear Mr. Dyson:

SUBJECT: FMVSS 1C8

We need a ruling on whether it is legal to use rear stop lights on a bus as follows:

1. When brakes are applied rear stop lights are steady burning under all conditions.

2. Place gearshift in reverse - two backup lights are energized and the two seven inch and two four inch rear stop lights flash at a frequency between 60 and 120 cycles per minute.

The purpose for such a system is to give school pupils and others additional warning in addition to the backup lights when the bus is in reverse gear and would not interfere with the stop light function. Thanks for an early reply.

Yours very truly,

BLUE BIRD BODY COMPANY;

W. G. Milby -- Project Engineer