Interpretation ID: 2669y

Mr. Ricky Bass
Q. C. Manager
Terminal Service Co.
P.O. Box 1200
Tallahassee, FL 32302

Dear Mr. Bass:

This is in reply to your letter of August 1, l990. You have asked whether it would be permissible to use a triple lamp cluster, each lamp containing a dual filament bulb, to perform identification and stop lamp functions on cargo tank trucks. The cluster would be mounted not less than l0 feet 6 inches above the road surface. You believe that with this design, the function of the identification lamp "will be intact."

In telephone conversations with agency personnel on September ll, l990, you clarified that you would like to have this device installed on all new tank trucks, and installed on vehicles in use when they are returned for extensive repairs. The device is intended to supplement the vehicle's conventional stop lamps.

With respect to new tank trucks, Standard No. l08 permits supplementary lighting equipment provided that it does not impair the effectiveness of lighting equipment required by the Standard. The determination of impairment is to be made initially by the truck manufacturer in its certification of compliance with all applicable standards, and if the decision appears to be clearly erroneous, NHTSA will so inform the manufacturer. In the present case, the required lighting devices that concern us are the identification lamps, and the conventional stop lamps. As the triple cluster will continue to be illuminated, though with a somewhat greater intensity in the stop lamp mode, we do not consider that the device would impair the effectiveness of the identification lamps.

As for whether the device would impair the effectiveness of the conventional stop lamps, we note that the triple lamp cluster will be located from 126 inches to 156 inches above the road surface. Under Standard No. 108, the conventional stop lamps cannot be located more than 72 inches from the road surface. We judge from the configuration of the tank truck that, in actuality, the lamps will be mounted substantially lower than 72 inches. We raise the possibility that the activation of the supplementary lamps, which are located at such a distance from the conventional ones, could create momentary confusion in a driver immediately following a truck equipped with the device.

You also wish to install the device on trucks in use, when they are due for major repairs. The sole Federal restraint upon modifications of this nature is that, when performed by vehicle or equipment manufacturers, distributors, dealers or repair businesses, they do not render inoperative, in whole or in part, any device or element of design installed in accordance with a Federal motor vehicle safety standard. As we understand it, your company would perform these modifications on its own vehicles. Therefore, the prohibition would not come into play. Even if the modifications were done by, for example, a motor vehicle repair business, it would be substituting one type of identification lamp for another. We see no problem with the substitution by itself. However, to the extent that the supplementary stop lamps might impair the effectiveness of the conventional stop lamps on new trucks, their installation by the repair business could be considered as rendering the conventional stop lamps partially inoperative, within the meaning of the statutory prohibition for vehicles in use.

Vehicles in use are also subject to the laws of the States in which they are registered and operated. Since we are not conversant with State laws, we suggest that you contact the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, for an opinion.

Sincerely,

Paul Jackson Rice Chief Counsel /ref:l08 d:9/24/90