NHTSA has issued interpretation letters stating that subsection (d) expressly applies to brake lamps. As noted to in a 1993 letter from NHTSA's Chief Counsel's office to David Lee, President of Lee Family, Inc.S5.5.10 The wiring requirements for lighting equipment in use are:
(a) Turn signal lamps, hazard warning signal lamps, and school bus
warning lamps shall be wired to flash;
(b) Headlamps and side marker lamps may be wired to flash for
(c) A motorcycle headlamp may be wired to allow either its upper
beam or its lower beam, but not both, to modulate from a higher
intensity to a lower intensity in accordance with section S5.6;
(d) All other lamps shall be wired to be steady-burning.
Granted, prohibitions on modifying safety equipment only apply to manufacturers, dealers, and commercial service centers so owner's could do this on their own. That's where the states step in. And as stated earlier, it is my understanding that all of the states prohibit flashing brake lamps of any kind consistent with federal law.Motor vehicle lighting in the United States is subject to both Federal and State requirements. The National Traffic and Motor Vehicle Safety Act and Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment are the Federal requirements to which I refer. Standard No. 108 prescribes requirements for center highmounted stop lamps that must be followed by the manufacturer of the vehicle, and met at the time the vehicle is sold by the dealer to its first owner. One of these requirements is that the center highmounted stop lamp be steady burning when it is in use.
I find that to be true when following a MC or a car with flashing 3rd light. It is not only attention grabbing, but also annoying so I stay away from it or get away from that vehicles behind....Jim C said:I know the lamp works because drivers have stopped well back of me after seeing the brake lamps flash. Not so before I installed my "experimental" lamp!