The late, great Ken Kifer discusses the dangers of sidewalk cycling and other matters of bicycle safety here: http://www.kenkifer.com/bikepages/health/risks.htm.

Here's another good site: http://bicyclesafe.com/

By the laws of all 50 states, the District of Columbia, and the Commonwealth of Puerto Rico, bicyclists have as much right to be on the streets as cars; actually, more, for a motorist uses the streets because he is licensed by and registered with to do so--his use is a privlidge--whereas a cyclist is exercising his common-law and constitutional right to travel--his use is an inherent right.