Originally Posted by
akohekohe
One thing to keep in mind about the law. It is not just a question of whether or not the police will enforce the law but also a question of your liability if you are in an accident. If you get hit by a car while you are using a flashing light on your bicycle and that is illegal in your jurisdiction you run the risk that some lawyer will use this as an excuse to find you are at fault. The lawyer will claim his client was confused by the bicycle who was riding with illegal equipment. This is why I got the law changed here in Hawaii to permit (but not require) bicycles to ride on the shoulder. No policeman ever ticketed a bicyclist for doing so but it could have been used against the cyclist if there was an accident. Same is true of a lot of laws. If you signal a right turn with your right arm instead of you raised left arm and get hit what will the lawyers say - you were improperly signaling your turn ... an so forth. You may say, well safety first, I'm going to use my strobe blinkie no matter what the law says because it makes me more visible. Well, hope you don't get hit, but if you will notice the number of threads where the moving Christmas trees got hit anyway it should be obvious the strategy doesn't always work. This is why it is a good idea to get the law changed even if the police are not ticketing for it.
Thankfully, there is no ambiguity in my state:
(1) Every bicycle when in use during the hours of darkness as defined in RCW
46.37.020 shall be equipped with a lamp on the front which shall emit a white light visible from a distance of at least five hundred feet to the front and with a red reflector on the rear of a type approved by the state patrol which shall be visible from all distances up to six hundred feet to the rear when directly in front of lawful lower beams of head lamps on a motor vehicle. A lamp emitting a red light visible from a distance of five hundred feet to the rear may be used in addition to the red reflector.
A light-emitting diode flashing taillight visible from a distance of five hundred feet to the rear may also be used in addition to the red reflector.
http://apps.leg.wa.gov/rcw/default.aspx?cite=46.61.780
Personally, I always use flashing, and I don't agree with the common hypothesis that it's harder to determine the range of a flashing light. What's fairly certain is that (1) the flashing mode is more distinctive and noticeable, particularly in an ocean of steady red lights in traffic; and (2) it's associated with bicyclists and pedestrians, giving the right cue to the motorist.
If you do want to give range cues, then divergence is a good way to have your cake and eat it too.
Bar-tip taillights, and/or a bike taillight plus a helmet taillight, have physical separation so the viewer can triangulate. As they get closer, the lights diverge.