Mr. Randy I. McClanahan
2323 Augusta, #5
Houston, Texas 77057

Dear Mr. McClanahan:

This is in response to your letter of February 14, 1996, on the subject "Deceleration Rate Signal Generator to Control the Operation of the Center High Mounted Brake Light of Vehicles."

Citing paragraph S5.5.10(a) of Motor Vehicle Safety Standard No. 108 which requires hazard warning signal lamps to be wired to flash, you believe that "the center high mounted brake light, when controlled by our Brake Alert deceleration rate signal generator, is in fact a `hazard signal lamp'". In your opinion, "the installation of our Brake Alert does not alter the factory-installed center high mounted brake light fixture or the bulb(s) therein", and, therefore "not in violation of any Federal Regulations."

I am sorry to have to tell you that your Brake Alert device is not permitted under Federal regulations. The hazard warning signal lamps covered in S5.5.10(a) refer to a vehicle's four turn signal lamps flashing simultaneously. Brake Alert, by causing the center high-mounted stop lamp to flash, would not change the center lamp into a "hazard warning lamp" within the meaning of Standard No. 108. When activated by Brake Alert the center lamp would simply be a flashing stop lamp. Under S5.5.10(d) of Standard No. 108, stop lamps must be steady burning. This means that Brake Alert could not be installed as original equipment on a vehicle.

With respect to the aftermarket, Federal law prohibits modifications by a manufacturer, distributor, dealer, or motor vehicle repair business that "make inoperative"

Federally-required equipment, such as the center stop lamp. We regard causing the center lamp to flash as the equivalent of making it inoperative because it will be operating in a way that is not permitted for new vehicle equipment under Standard No. 108. Federal law, however, does not prohibit the vehicle's owner from adding Brake Alert if (s)he is capable of doing so. Even if installed by the vehicle owner, the legality of Brake Alert would be determinable under the laws of the states where it is operated. If you would like to know whether state laws would permit the use of Brake Alert, we suggest that you write the American Association of Motor Vehicle Administrators for an opinion. Its address is 4600 Wilson Boulevard, Arlington, Va. 22203.

For your information, I am enclosing a copy of an earlier agency interpretation on the use of the center lamp as a flashing deceleration warning device (see page 2 of letter of June 3, 1990 to Norman H. Dankert).

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


Samuel H. Dubbin Chief Counsel

Enclosure ref:108 d:4/2/96