Injury is a leading cause of death and disability for America's young adults and children. It is the leading cause of death for those from ages 1 to 44 (Mokdad et al., 2004) and is the fifth leading cause of death for all Americans (Centers for Disease Control and Prevention, 2001). Injuries are associated with higher treatment costs than the other three leading causes of death. Traffic accidents are the leading cause of severe brain injury, as well as most paraplegic and quadraplegic cases (Spielberger & Frank, 1992).

For many years, injuries were viewed as ‘accidents’ that were inevitable and not responsive to prevention efforts. Injury events tended to be attributed to human error or misaction; individuals died or were injured due to driving while intoxicated or a leg was broken when someone failed to watch their step. This psychological model of injury was related to the emergence of the concept of ‘accident-proneness’ during the 1930s and 1940s. In this approach, accidents occurred to individuals as a function of unconscious wishes or desires (Waller, 1994).

Injury events were also attributed to human error or misaction because they often involved relatively rare events that were perceived as unpredictable. Many data systems tended to record only ‘single’ causes of injury, negating the idea that a crash may occur both because the driver is impaired by alcohol and because the roadway geometry at the crash location is inadequate (Waller, 1994).