Bicycle accident statistics in the U.S.A. are usually obtained by counting accident numbers rather than measuring accident rates. As part of a larger study of bicycling safety, the bicyclist’s exposure to risk was measured in terms of the number of times each of 851 functions were encountered. Data from a roadside census survey showed that bicyclists were forced using major highways both by the design of the road systems and by the bicyclist's preferences in route choice.
Abstract