The question of whether drivers alter their behavior (risk compensation) due to vehicle safety improvements or public policy changes(laws, enforcement) has been debated for some years. For example, drivers may go faster or operate in a less safe manner in response tosuch a change. This paper examines whether risk compensation occurred due to the 1985 mandatory seat belt use law in Illinois. It also compares the results of the before/after method to a preferred technique (ARIMA, developed by Box and others). These approaches are applied to monthly totals and rates of fatalities, injuries classified by level of severity, and total accidents from 1980-1991. Three typesof accident are analyzed: vehicle/pedestrian, vehicle/bicycle, and all others. If nonoccupants have suffered adverse consequences, riskcompensation could provide the explanation. Much less evidence of offsetting behavior was found. No statistically significant increase in accidents occurred. While other types of safety changes may alterdriver behavior, this did not seem to occur in Illinois due to the belt use law. (A)
Samenvatting