United States Department of TransportationInterpretation ID: 1652y
213 S. Pleasant
Prescott, AZ 86303
Dear Mr. Perkins:
Secretary Burnley has asked me to respond to your letter of September 7, 1988, with respect to your lighting device. In essence, this is a center high-mounted stop lamp, with turn signal lamps adjacent to it. You believe that high-mounted turn signals "joined with the rear window brake light should have a dramatic effect on rear and side collisions", but you have been told that "this conception is at present illegal."
Paragraph S4.4 of Federal Motor Vehicle Safety Standard No. l08 states that "no high-mounted stop lamp shall be combined with any other lamp or reflective device." We interpret this as prohibiting lamps or reflective devices that share a single lens or compartment with the center highmounted lamp. Your device shows lamps adjacent to the center highmounted lamp but not combined with it. Therefore, your device is not prohibited by that paragraph of the standard if you wish to market this device as original equipment. The next question to ask is whether it impairs the effectiveness of required lighting equipment (paragraph S4.1.3), principally the center stoplamp. For example, if the yellow turn signals were too bright or if the color of the turn signal were red, these lamps might "impair the effectiveness" of the center stoplamp. However, this is a determination to be made, in the first instance, by the manufacturer of the vehicle who must certify compliance with Standard No. l08.
If you wish to sell your device in the aftermarket, it is acceptable under Federal law if its installation does not adversely affect the operation of motor vehicle equipment installed in accordance with a Federal motor vehicle safety standard so that the equipment would no longer comply with the standard. Assuming that the installation does not have this effect, the legality of installing or using such a device must then be determined according to the laws of any State in which a vehicle so equipped is registered or operated, and these auxiliary lamps must comply with any State requirements. We cannot advise you on State laws. One source of advice is the American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203.
Sincerely,
Erika Z. Jones Chief Counsel
ref:108 d:l/l8/89