Mr. Tom Barron
320 Putnam
Springdale, Arkansas 72764

Dear Mr. Barron:

Thank you for your letter mailed April 10, 1996, telling the Department of Transportation of your "Saf-T-Lit" invention. This consists of a two-lamp unit containing a stop lamp and a turn signal lamp. These lamps would be mounted on each side of a semi trailer, at the top. In your view, they are needed because the original equipment lamps mounted at the bottom of a trailer may be obscured by intervening traffic, or by snow or fog.

The National Highway Traffic Safety Administration (NHTSA) is the agency within the Department that establishes the Federal motor vehicle safety standards that apply to the manufacture of vehicles, including trailers. The Federal Highway Administration is the agency that establishes similar standards for the operation of commercial motor vehicles, including trailers, in interstate commerce.

Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices and Associated Equipment , is the safety standard that applies to original equipment lighting for vehicles, including trailers. Under Standard No. 108, a trailer manufacturer may locate rear turn signal lamps at any point it chooses between 15 and 83 inches above the road surface, and stop lamps between 15 and 72 inches.

Under Standard No. 108, your invention is regarded as supplementary lighting equipment, and it is permissible as original equipment if it does not "impair the effectiveness" of the other lighting equipment required by Standard No. 108. We regard original equipment as including equipment that a dealer may install after receiving a new vehicle from the factory and before the sale of the vehicle to its first purchaser. In your case, we do not believe that your invention , as you have described it to us, would impair the effectiveness of any other rear lighting equipment. However, your diagram shows your lamps in the location generally occupied by clearance lamps. Standard No. 108 requires that trailers whose overall width is 80 inches or more have a pair of clearance lamps to indicate the overall width of the vehicle and located as near the top as practicable. Thus, your invention could not be installed to replace these lamps without creating a noncompliance with Standard No. 108. We assume that your invention would therefore be mounted below these lamps.

With respect to the aftermarket, there is no Federal restriction on the sale of supplementary lamps but the question under Federal law is whether their installation by a manufacturer, distributor, dealer, or motor vehicle repair business (this does not include the owner's own service facilities if restricted to its own vehicles) would "make inoperative" any of the lighting equipment required by Standard No. 108. Generally, we interpret "make inoperative" to equate to "impair the effectiveness". We have previously concluded that your invention is not likely to impair the effectiveness of the required lighting equipment if installed before the initial sale of a trailer, and, for this reason, we do not believe that your invention would have an inoperative effect on other rear lighting equipment when installed after the initial sale of the vehicle, keeping in mind my previous comment about the clearance lamps. The Office of Motor Carriers of the Federal Highway Administration has advised that operation of semi trailers with your invention installed would be permissible under its regulations, provided that the installation does not impair the effectiveness of the lighting equipment required by Standard No. 108.

Please bear in mind that the sale and use of supplementary lighting equipment, though permissible under Federal law, is also subject to the laws of the individual states. We are unable to advise you on state law but an interpretation can be provided by the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203.

We appreciate your writing us of your concerns and your efforts to improve safety on our nation's highways. If you have any questions, Taylor Vinson of this Office will be pleased to answer them. His phone number is 202-366-5263.


Samuel J. Dubbin Chief Counsel ref:108 d:5/16/96