Getting off your bike: cycling accidents in Great Britain in 1990-1999.

The paper extracts and tabulates selected incidence and fatality rates of cycling accidents recorded by the police in Great Britain during 1990-1999, in a database of over 30,000 standardised reports of fatal or serious injury accidents. Since usable estimates of exposure to risk in cycling are not available, the concept of exposure invariance is developed to estimate the relative risk of different sorts of bicycle/vehicle encounter. Any bias from under-reporting of serious injury accidents is shown to be boundable if the probability of under-reporting is constant.