The California Vehicle Code says:
(d) A bicycle operated during darkness upon a highway, a sidewalk where bicycle operation is not prohibited by the local jurisdiction, or a bikeway, as defined in Section 890.4 of the Streets and Highways Code, shall be equipped with all of the following:
(1) A lamp emitting a white light that, while the bicycle is in motion, illuminates the highway, sidewalk, or bikeway in front of the bicyclist and is visible from a distance of 300 feet in front and from the sides of the bicycle.
I have a pretty bright Cygolite headlight, but it emits practically no light from the sides, if you look at a 90 degree angle you can't see any light at all from the headlight.
Is this strictly legal under the law? I do supplement with a blinky light that provides some side illumination (though I'm not sure you could see it from the sides at 300 feet from the bike), but I'm wondering if my headlight meets the letter of the law? If I'm ever in an accident, I don't want the other driver to be able to say "How could I have seen him, he didn't even have the headlight required by law!"
I've looked at a few other states but they didn't have any requirement for side visibility of the headlight.