Alert: Wonky stuff ahead.
Although the absolute numbers of bicycle crashes in California have long been available through the Statewide Integrated Traffic Records System (SWITRS), evaluating crash risk has been difficult because of poor exposure data — we don’t track the number of miles people ride on a daily basis like we do for automotive traffic. Although statewide data is still limited, researchers from UCLA and UC Berkeley used newly available bicycle count data to better evaluate crash risk. They used this exposure data to better determine what factors (socioeconomic and infrastructure) correlate to higher crash risk.
Red dots on this map show bicycle crashes as logged through the California Highway Patrol dispatch system, January 1 2016 through August 2 2016. This map is updated every 15 minutes. Click map for the updated zoomable view.