Relative fatality risk in different seating positions versus car model year

Fatality risk of drivers compared to right-front passengers is examined vs. car model year (MY) using Fatal Accident Reporting System (FARS) data for 1975 through 1986. Confounding effects are removed by comparing unrestrained occupants matched in sex and age (to within three years). MY greater than or equal to 1968 cars, which complied with Federal Motor Vehicle Standard 203 (impact protection for the driver) and FMVSS 204 (rearward column displacement), are compared to MY less than or equal to 1966 cars, which did not comply with these standards. It is found that, compared to right-front passengers in the same cars, drivers had higher relative fatality risks in MY greater than or equal to 1968 cars and lower relative fatality risks in MY less than or equal to 1966 cars. Because there are so few fatal frontal crash data for MY 1966 and MY 1968 cars, definitive conclusions regarding the effectiveness of FMVSS 203 and 204 in reducing driver fatalities are not possible. However, our analysis, together with the assumption that right-front-passenger fatality risk was the same in 1966 and 1968 MY cars, does suggest that a previous 12% effectiveness estimate is more likely to be high than low.