In the meantime, a totally excellent example of public data sharing and professionally-managed crowd-sourced journalism: The Bay Citizen's Bike Accident Tracker. Maps, charts, data. Agent at fault, type of crash. Really great stuff.
|Click to enlarge--and note the customized search/sort featers at left.|
Aggregated results: Contra Costa County is the worst. Not for the total number of crashes, but for the percentages of bike commuters who are involved in accidents. From 2005 to 2009 there was an average of 288 accidents involving cars and bicycles in CC, or 11% of the roughly 2568 bike commuters.
San Francisco, though it posted far more accidents, also posted far more commuters--and only 4% of them were involved in crashes.