Skip to main content
Search Interpretations

Interpretation ID: 0849

Ms. Teresa Thompson
1686 Desoto Trail
Dalton, GA 30721

Dear Ms. Thompson:

We have received your letter of April 6, 1995, with respect to an automotive deceleration signal. You have asked for information "on how to have this product tested and approved as well as information on the legal ramifications and liabilities for the product."

The Department of Transportation neither tests nor "approves" products. What it does do is to advise whether motor vehicle equipment is permitted under the statutes and regulations for whose administration it is responsible. In this instance, the appropriate regulation is Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices and Associated Equipment. This standard specifies requirements for only certain items of lighting equipment but it also has an effect on lighting equipment that is not specified in the standard. That is to say, if an item of lighting equipment is not allowable for a manufacturer or dealer to install as original equipment (i.e., equipment on the vehicle at the time of its original sale), in most cases it won't be allowable in the aftermarket for manufacturer or dealer installation on used vehicles as well.

As you describe it, the signal is provided by "a strobe light with an independent power supply, which upon heavy breaking (sic), will activate a strobe for five seconds and on impact for ten minutes." The prototype "is approximately 4" by 3" and may be attached to a rear window."

Federal laws cover brake activation of your strobe signal. Standard No. 108 requires turn signal lamps, hazard warning signal lamps, and school bus warning lamps to flash. Headlamps and side marker lamps may be flashed for signaling purposes. But all other lamps provided as original equipment must be steady-burning. We regard a strobe lamp as one that flashes. For this reason, the deceleration signal you describe could not be installed as original equipment. Further, its installation on a used vehicle would take the vehicle out of compliance with Standard No. 108.

Notwithstanding the discussion above, there is no Federal prohibition on the sale of the strobe signal device, and Federal law does not prevent the vehicle owner from installing it on a used vehicle (however, manufacturers, dealers, distributors, and motor vehicle repair businesses may not do so), no matter what effect the strobe signal may have upon compliance with Standard No. 108. However, the States have the right to decide whether use of the strobe signal is permissible. We aren't able to provide you with information on State laws, and suggest that you seek an opinion from the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22303. We can't advise you on your potential liabilities either, and suggest that you contact your attorney for an opinion on the applicability of local law.

In addition, it is important to note that Standard No. 108 prohibits supplementary original lighting equipment that impairs the effectiveness of the original lighting equipment required by Standard No. 108. The proximity of your strobe device in the rear window to the center highmounted stop lamp required by Standard No. 108 raises the possibility of impairment, especially if the strobe is of a color other than red, or so bright as to mask the center stop lamp signal.

I am sorry to be unable to offer you more encouragement at present, as we share your concern with the negative effects of fog and rain on drivers and vehicles. It is obvious that you have given much thought to this problem. Noting that you are testing a prototype, this agency would be interested in receiving any data you have or may develop showing a positive effect of the strobe signal upon the frequency and severity of rear end collisions. You may send this to Michael Perel, Office of Research and Development, NHTSA, Room 6206, 400 Seventh St. SW, Washington, DC 20590. It is conceivable that at some time in the future we would allow the center stop lamp to flash under conditions of rapid deceleration. This could open the way to permissibility of an additional lamp such as yours.

I note that, to the extent that your device were only to activate upon impact and not during conditions of rapid deceleration, it would not be prohibited by Standard No. 108. Such a device would be permissible as a supplement to, or

substitute for, a vehicle's hazard warning signal system. We do not know whether it would be permissible under State laws (see discussion above).

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

Sincerely,

John Womack Acting Chief Counsel

refL108 d:5/11/95