The Effectiveness of the 55 MPH National Maximum Speed Limit as a Life Saving Benefit. Executive Summary

摘要

The following report contains an analysis of the life saving benefits resulting from the 55 mph NMSL from 1974-1979. Monthly fatality data from 1970-1979 was used in a time series model to arrive at the estimated safety benefits (lives saved). The time series model relates changes in monthly fatalities to changes in monthly vehicle miles traveled, introduction of safety improvements and the implementation of the 55 mph NMSL law. Increases in highway fatalities in 1976-1979 compared to the 1974-1975 level led to a detailed examination and analysis of the composition of these fatalities in order to determine possible causes for the increases. Based upon the available data, it was concluded that 55 mph compliance had eroded somewhat in 1977 and 1978 thus resulting in some fatality increases.