[island_dude]

This is a pretty complex topic. I think there are some key points though:
Riders are inherently more vulnerable. Increasing visibility can help cars notice us. Being noticed doesn't mean that other drivers will act on the awareness. for example: I read about a very informal and unscientific study done to gage visibility and number of right of way violations. A rider dressed up in black and road an all black cycle. Later he dressed in high visibilty clothing and road a light colored bike. A third time he dressed up in black, wore his motorcycle club ID on his chest like an ID. and Generally acted like a motorcycle cop.
His conclusion was that even though he was not as visible in the faux-cop outfit, he posed more of a visible threat to the surounding cars. this lowered the overall number of right of way violations he encountered more than wearing the high visibilty clothing and bike.

Motorcycles are not considered a threat to car drivers in the same way larger vehicles are. I think most drivers notice bikes, but fail to act on them as a competing vehicle.

Anyway, this is just part of what is going on.