Interpretation ID: nht95-4.80

TYPE: INTERPRETATION-NHTSA

DATE: November 17, 1995

FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA

TO: Jim Young -- Wheeled Coach

TITLE: NONE

ATTACHMT: ATTACHED TO 10/17/95 LETTER FROM Jim Young to John Womack (OCC 11303)

TEXT: Dear Mr. Young:

This is in reply to your FAX of October 17, 1995, asking for interpretations of Motor Vehicle Safety Standard No. 108, as in relates to "customer specifications for options incorporated into, or in addition to FMVSS lighting." You have described these op tions as:

"Brake override circuit for rear facing warning lights. The rear warning lights flash as warning lights until the brakes are applied, at which time they become stead burn. This option is in addition to the standard brake lights. If this is acceptable, should the lights be required to meet all requirements of stop lights? (ie.; maximum luminous intensity, color, etc. . .)"

As you clarified in a phone conversation with Taylor Vinson of this Office on November 2, the "rear facing warning lights" are part of the ambulance lighting system which is not a system required by Standard No. 108. This option is permissible. Althoug h there is no Federal legal requirement that governs the performance of ambulance warning systems, we recommend that the rear facing warning lights are red, the required color for stop lamps, inasmuch as the intent seems to be provide an additional indic ation that the brake have been applied.

"Brake Enhancer. Standard or additional stop lights are made to flash on/off several times before going steady burn."

This is not permissible. Standard No. 108 requires all stop lamps to be steady burning.

"Back-up alert strobes. Rear facing high intensity strobe lights that are activated when the gearshift lever is placed into reverse gear."

Optional equipment is permissible if it does not impair the effectiveness of lighting equipment required by the standard. You have not indicated the color of the strobe lamps. If they are red or amber, they could cause confusion in the eyes of an obser ver when operated simultaneously with the steady burning

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white backup lamp. There is a lesser possibility of confusion if they cast a white light, as long as they do not mask the steady burning backup lamp. In that event, the strobes could be fitted to the ambulances.

"Taillight flashers. Taillights or brake lights are flashed alternate to backup lights until brakes are applied, at which time they go steady burn. The option at times may be requested to only work of the rear doors on the ambulance are open."

This is not permissible. Standard No. 108 requires taillamps as well as stop lamps to be steady burning, under all circumstances.

If you have further questions, you may refer them to Taylor Vinson (202-366-5263).

Sincerely,