THE IMPACT OF THE 65 MPH SPEED LIMIT ON VIRGINIA'S RURAL INTERSTATE HIGHWAYS THROUGH 1990

In April of 1987, Congress passed the Surface Transportation and Uniform Relocation Assistance Act (STURAA), which permitted states to raise their maximum speed limit on rural interstate highways (rural interstates) to 65 mph. Virginia's 65 mph speed limit went into effect July 1, 1988, for passenger vehicles and on July 1, 1989, for commercial buses. This report is the fourth in a series of reports to examine the 65 mph speed limit in Virginia and summarizes 30 months of experience with the 65 mph speed limit. Following the implementation of the 65 mph speed limit, average and 85th percentile speeds increased on Virginia's rural interstates, and fatal crashes and fatalities increased significantly. On Virginia's urban interstates, on which the speed limit remained at 55 mph, there was a smaller increase in average and 85th percentile speeds, but there was not a significant increase in fatal crashes or fatalities. National data show a substantial increase in rural interstate fatalities in states that increased the rural interstate speed limit to 65 mph and a decrease in states that maintained a 55 mph speed limit. The data in this report clearly show that speeds, fatal crashes, and fatalities increased on Virginia's rural interstates after the implementation of the 65 mph speed limit. However, these data do not reflect causation. It is possible that factors other than the change in the speed limit--such as changes in traffic volumes, trip patterns, or trip purposes--are responsible for part or all of the increase in fatal crashes and fatalities. Causative issues will be addressed in the final report in this series, to be published in 1993.