Headlight Modulators
The legality of headlight modulators comes into question occasionally, and both CHP officers and local constables tend to be unaware of the legal status of these devices. Put simply, they are legal throughout the United States and Canada.
Section 108 of the Federal Motor Vehicle Safety Standards regulates modulated headlights. California Vehicle Code 25250-25251 specifically allows them. And, Title 49 of United States Code 30103(b1) forbids any state from prohibiting them.
Here are the California Law specifics:
25251.2. Any motorcycle may be equipped with a means of modulating the upper beam of the headlamp between a high and a lower brightness at a rate of 200 to 280 flashes per minute. Such headlamps shall not be so modulated during darkness. (Added by Stats. 1980, Ch. 35, Sec. 1. Effective March 7, 1980.)
