Effects of policy related variables on traffic fatalities : an extreme bounds analysis using time-series data.

This study finds that reducing speed limits (to 55 mph) in the U.S results in a reduction of fatality rates. In addition, the proportion of newer vehicles on the highways (subject to newer safety regulations) has a significant effect on fatality rates. The analysis is conducted using extreme bounds analysis applied to a time series model of the determinants of U.S. fatality rates. This model incorporates many policy and socio-economic variables.