Each year over one-half million injuries associated with bicycles are estimated to have occurred based on the CPSC's National Electronic Injury Surveillance System. Data is collected for NEISS through hospital emergency rooms. The CPSC further estimates that approximately 610,000 other bicycle related injuries were treated in other medical settings.(25)

Contrary to popular fears, most bicycle-associated injuries are not related to motor vehicle collisions. According to the National Highway Traffic Safety Administration (NHTSA), there were only 88,000 police-reported car-bicycle accidents in 1986. 1,000 of these were fatalities, 12,000 were hospitalized and 45,000 received some other medical treatment.(26) The National Safety Council estimates from reports by city and state traffic authorities that in 1988 there were 58,000 non-fatal injuries and 1,100 deaths from "pedalcycle"-motor vehicle collisions.(27) John Forester estimates that bicycle-motor vehicle and bicycle-bicycle collisions each count for another 18% and the remainder result from collisions with other objects including dogs (14%) or just plain falls (50%).(28) Kenneth Cross attributes bicycle-motor vehicle accidents as causing only 5.5% of all bicycle-related injuries and Dan Burden suggests that such accidents cause only 1% of all bicycle related accidents.(29) The differences in these estimates may result from the base number of accidents. If minor, unreported falls are included, bicycle-motor vehicle accidents account for a much smaller proportion of accidents than they do as a proportion of serious accidents.(30)

The primary cause of bicycle-associated injuries is operator error. Forester estimates that one-half of all bicycle accidents result from this.(31) A recent survey, at the University of Kansas Medical Center, of 492 bicyclists involved in accidents reported that 59% considered themselves to be at fault.(32) Even simple misjudgments can cause significant falling injuries because bicycles are inherently unstable and provide little protection to operators.(33)

Despite the relatively large number of annual bicycle-associated injuries, only about 1 in 500 emergency room-treated injuries is a fatality.(34) The NHTSA counted 949 police-reported bicyclist fatalities in 1986 from bicycle-motor vehicle collisions.(35) The National Safety Council estimated 1,100 pedal cyclist fatalities occurred from motor vehicle collisions in that year.(36) The National Center for Health Statistics counts 92 pedal cyclist fatalities from non-motor vehicle accidents.(37) In contrast to non-fatal injuries, about 90% of all bicycle-associated fatalities occur from automobile collisions.(38)

Moreover, head injuries appear to be the major cause of fatalities. In an early study, Dr. Daniel Fife et al. examined 173 fatally injured bicyclists in Dade County, Florida between 1956 and 1979. They found that the head and neck region was most seriously injured in 86% of the cases.(39) Similarly, the Calgary study found that 67% of bicycle fatalities were caused by head injuries, and an Australian study estimates that 80-85% of all bicycle fatalities are caused by head injuries.(40) Of course, not all head injuries are fatalities - or even serious. A recent study of 100 bicyclists with head injuries in Great Britain found that only 11 were admitted to a hospital for treatment and only one died.(41)

As Table 1(42) shows, annual bicycle injury and fatality rates per participant in the U.S. are comparatively low. Still, non-fatal injuries are quite frequent. Some estimate that one in every 20 bicyclists is injured annually.(43) A bicyclist can expect a minor injury every three years and a more serious one every fifteen.(44)