More than 52,000 bicyclists have been killed in bicycle traffic accidents in the U.S. over the 80 years the federal government has been keeping records. When it comes to sharing the road with cars, many people seem to assume that such accidents are usually the cyclist’s fault — a result of reckless or aggressive riding. But an analysis of police reports on 2,752 bike-car accidents in Toronto found that clumsy or inattentive driving by motorists was the cause of 90 percent of these crashes. Among the leading causes: running a stop sign or traffic light, turning into a cyclist’s path, or opening a door on a biker. This shouldn’t come as too big a surprise: motorists cause roughly 75 percent of motorcycle crashes too.
Riding in traffic is relatively nuts -- you have to assume that all the cars around you are sociopathic homicidal maniacs that don't see you and don't care if you die.
But if you get passed that, cycling is fun.