Originally Posted by
Falchoon
If you are coming to an intersection and the car is at 90 degrees to the bike, the lights are going to be virtually useless as they aren't pointed that way. Unless you happen to have some sort of side lights, but I don't know any cyclists that have these, and what colour would thety need to be if you did?
Bike lights with decent intensity will make a pool of light on the roadway and light up signs and other objects. That isn't as good as having the light shining directly at the observer, but it helps. Many lights do have a little bit of side visibility as well.
The best thing is to have a helmet light, so you can point it at drivers who might not see a headlight on the bars. I use both.