P.O. Box 8618
Midland, TX 79708-8618
Dear Mr. Lawrence:
This is in reply to your letter of April 4, 1997, telling us about your "Brake Light Delay System" and "Blinker Delay System", and asking for an opinion "regarding the legality and use of these systems."
The "Brake Light Delay System" is spliced into the wiring of the stop lamp switch and has the effect of delaying deactivation of the stop lamps for approximately 6 seconds after the operator's foot is removed from the brake pedal. You envision installation of the System on a truck tractor-trailer combination so that when the truck tractor begins to accelerate after it has turned, the delayed stop lamp will indicate to a driver following that (s)he must continue to exercise caution
I am sorry to tell you that Federal law does not allow installation of the "Brake Light Delay System", either as original or aftermarket equipment. Under paragraph S5.5.4 of Motor Vehicle Safety Standard No. 108, stop lamps must be activated upon application of the service brakes. We have interpreted this to mean activation only upon application of the service brakes. Thus, continued activation of the stop lamps after application of the service brakes has ceased would result in a vehicle's failure to comply with paragraph S5.5.4. We appreciate your offer to provide one of these systems for evaluation, but because Federal law does not allow the system, we must decline your offer.
I remarked above that your System cannot be installed in the aftermarket. The regulations of the Federal Highway Administration (FHWA) for commercial vehicles operated in interstate commerce prohibits motor carriers from installing your system if it results in a noncompliance with Standard No. 108. The FHWA requires that commercial motor vehicles manufactured on or after March 7, 1989, meet the requirements of Standard No. 108 in effect at the time the vehicle was manufactured. The FHWA also prohibits the use of additional equipment or accessories that are inconsistent with its regulations. Therefore, your system may not be installed on commercial motor vehicles manufactured before March 7, 1989.
Please note that State laws for interstate commercial motor vehicles are consistent with, if not identical to, the FHWA's requirements. Also, the States are required to have intrastate safety regulations that fall within the FHWA's Tolerance Guidelines. Under this circumstance, the legality of the use of your system on commercial motor vehicles operated exclusively in intrastate commerce would be determined by the laws of the States in which the System would be used. We are unable to provide you with an interpretation of relevant State laws and suggest that you consult the Department of Motor Vehicles of the various States.
Your "Blinker Delay System" is intended to prevent the automatic cancellation of the turn signal system for 3 to 4 seconds after the front wheels of a towing vehicle have been straightened, again to indicate that a turn has not been completed. You note that "most tractor trucks have a blinker system that must manually be switched off to deactivate the blinker," and that the "Blinker Delay System" is intended for other trucks. Under paragraph S220.127.116.11, turn signals on all motor vehicles less than 80 inches in overall width must be self-canceling by steering wheel rotation. Thus, installation of this device would also create a noncompliance with Standard No. 108. For the same reasons, and with the same exception, noted above, this device would not be acceptable as either original or replacement equipment on motor vehicles required to comply with paragraph S18.104.22.168.
If you have further questions, you may refer them to Taylor Vinson of this Office (202-366-5263).
Acting Chief Counsel