Ms. Kerry Legg
Safety & Compliance Manager
25 DeBaets Street
R2J 4G5 Canada
Dear Ms. Legg:
This responds to your letter regarding permissible colors for illuminated destination signs on the front of new transit buses, under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment. You state that a customer has requested installation of signs capable of illuminating route designations and other messages in a variety of colors, including red, green, and blue. You believe that lighting equipment on the front of the vehicle must illuminate within the color spectrum from white to amber, adding that you have seen specific limitations to this effect under California State law. You ask whether such red, green, and blue lighted signs are prohibited under FMVSS No. 108. As explained below, given only the description you offer of the subject lighting system, the answer to your question is yes.
By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue FMVSSs that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. 30111 and 49 CFR Part 571). It is the responsibility of manufacturers to certify that their products conform to all applicable safety standards before they can be offered for sale (see 49 U.S.C. 30115 and 49 CFR Part 567). FMVSS No. 108 sets forth the requirements for both new and replacement motor vehicle lighting equipment.
We note that the agency addressed the issue of color of vehicle lighting equipment in a July 29, 2002 letter of interpretation to Trooper Lawrence Richardson (“Richardson letter,” copy enclosed). Our interpretation of FMVSS No. 108 has not changed from the opinion of the Richardson letter.
Under Federal law (i.e., FMVSS No. 108), the only permissible colors of light that may be emitted by original required equipment lighting on new vehicles are red, amber, or white. Furthermore, the standard requires items of replacement equipment to emit the same color light as the original equipment that they are designed to replace.
Accessory equipment (i.e., lighting equipment not required under the standard) is permissible on new vehicles, provided that it does not impair the effectiveness of lighting equipment required by Standard No. 108 (see S5.1.3). We interpret this as a general prohibition on lamps of colors different than red, amber, or white, because of the possibility that non-standard colors could cause confusion in other drivers, thereby diverting their attention from lamps that signal driver intention, such as stop lamps or turn signal lamps.
Turning to the specifics of the issue presented in your letter, we first note that permissible colors for lamps on the front of a bus are limited to amber or white. Use of supplemental red lamps on the front of a vehicle, such as the destination signs to which you refer, could cause confusion with brake or stop lamps. The color green typically conveys the message that one may proceed, so it could cause confusion with other red or yellow lamps that seek to warn or caution. Finally, blue is a color that some States reserve for use on emergency vehicles, so drivers unexpectedly encountering blue lamps on other types of vehicles could take potentially inappropriate actions.
Generally, if certain accessory lighting is not permissible on new vehicles, commercial entities will not be permitted to install the lighting as an aftermarket accessory for vehicles in use. The legal consideration is whether the accessory makes inoperative in any way a lamp required under and installed in accordance with Standard No. 108 (see 49 U.S.C. 30122). Usually, we equate impairing the effectiveness of a required item of lighting equipment with “making inoperative” such equipment in part, a violation of §30122.
Federal law does not prohibit a vehicle owner personally from making any safety equipment inoperative on his or her own vehicle, although the agency strongly discourages disabling any safety system. However, whether non-standard lighting equipment is allowable on vehicles in use is a matter of State law.
Based upon the above analysis and the description offered by you of the subject lighting system, under FMVSS No. 108, a manufacturer of new transit buses would not be permitted to install destination signs on the front of a vehicle that illuminate in red, green, or blue, because the lighting devices in those colors could impair the effectiveness of other frontal lighting equipment required under FMVSS No. 108.
If you have further questions, please feel free to contact Eric Stas of my staff at this address or by telephone at (202) 366-2992.
Anthony M. Cooke