Systemwide implications of the repeal of the national maximum speed limit

Abstract

The adoption of higher rural interstate speed limits may shift behaviors in ways that broadly affect motor vehicle safety. In particular, these laws may attract drivers from less safe rural noninterstate roadways, implying that any negative implications of higher speed limits for rural interstate fatalities may be attenuated by fewer rural noninterstate fatalities. We test for the reallocation of vehicle miles traveled and fatalities using 1982-2002 U.S. data spanning the relaxation and repeal of the national maximum speed limit (NMSL) across all drivers and specifically those younger and older drivers associated with higher fatality risks. Overall, we find that the repeal of the NMSL resulted in a 36-37% increase in fatalities on rural interstate highways. However, we found very little support for any decrease in rural noninterstate driving or fatalities following the adoption of higher speed limits on rural interstates.