http://www.nhtsa.dot.gov/.../staticf...OTHS809572.pdf
http://www.nhtsa.dot.gov/.../staticf...006/810802.pdf
These two links get you to some National Highway Traffic Safety Administration data and its analysis, on pedalcyclist/automobile crashes. The first paper was extensively reviewed within NHTSA before publication. I'd call it a primary source, being based on a compilation of police-reported collisions involving bikes and cars from all 50 states.