The effects of the 70 mph maximum speed limit on fatal crashes in the state of Texas

In December 1995, the State of Texas increased the maximum speed limit from 65 MPH to 70 MPH as a response to the repeal of the national maximum speed limit. This study examines whether there was a significant trend of increased highway traffic fatalities associated with the change in maximum speed limit. This research analyzed fatal crash data collected from the Texas Fatal Accident Reporting System covering December 1990 to November 2000. Time-series methods were used to examine the effects of the maximum speed limit change on the proportion of fatal crashes at speed limit ≥55 MPH, on interstate highways and subgroups divided by light condition, days of the week, drunk drivers involved, number of vehicles involved and location of crashes. None of the effects for either the total sample or any of the subgroups analyzed were statistically significant. The results indicate that the increase in the maximum speed limit did not affect the existing trend of fatal accidents.