Estimation of seat belt effectiveness values using double pair comparison method based on state highway crash data

The purpose of this study was to estimate the seat belt effectiveness in preventing fatal and nonfatal injuries to motor vehicle occupants when they are involved in crashes. The double pair comparison method was used and the estimations were based on police reported highway crash data of the state of Kansas in the United States. Two vehicle groups were considered: passenger cars and other passenger vehicles (vans and pickup trucks). Only front seat occupants who are older than 14 years of age were considered in the analysis. Based on estimations, seat belts were found to be 53% effective in reducing fatal injuries to front seat occupants in passenger cars. In other passenger vehicles, effectiveness of seat belts in reducing fatal injuries is 57%. As far as nonfatal injuries are concerned, seat belts are 52% and 42% effective in reducing incapacitating and non-incapacitating injuries respectively in passenger cars. It was also found that seat belts are 34% effective in reducing possible injuries to front seat occupants in passenger cars. Seat belts reduce incapacitating injury risk to occupants in other passenger vehicles by 47%, while they reduce non-incapacitating injury risk by 42% in the same vehicle group. In addition, seat belts are 28% effective in reducing possible injuries to occupants in other passenger vehicles.