EFFECTS OF THE 65-MPH SPEED LIMIT ON TRAFFIC ACCIDENTS IN OHIO
The effects of the 65-mph speed limit on traffic accidents on rural Interstate highways posted at 65 or 55 mph and rural non-Interstate highways posted at 55 mph in Ohio were examined by analyzing the accident data for 36 months before the implementation of the speed change law and an equal number of months after the implementation. The changes in accident rates, that is, the average number of accidents per month, were examined relative to weather conditions and seasons as well as day of week, time of day, light conditions, and vehicle mix. It was found that fatal accident rates on rural Interstate highways posted at 65 mph or rural non-Interstate highways posted at 55 mph had not significantly changed after the implementation of the 65-mph speed limit. Fatal accdient rates on rural Interstate highways posted at 55 mph showed an increase in the "after" period. However, when the data were categorized according to weather conditions, no significant change in fatal accident rates was found. There have been some increases in injury and property damage only (PDO) accident rates on rural Interstate highways posted at 65 mph. The injury and PDO accident rates on rural Interstate highways posted at 55 mph have decreased and shown no indication of adverse "spillover" effect. Injury and PDO accidents as well as the severity of accidents have decreased on the non-Interstate highways posted at 55 mph, perhaps indicating positive effects of the seat belt law, speed enforcement, and geometric and operational improvements in recent years.
This paper appears in Transportation Research Record No. 1375, Safety Research: Enforcement, Speed, Older Drivers, and Pedestrians.
Transportation Research Board
500 Fifth Street, NW
Pant, P D
Adhami, J A
Niehaus, J C
Transportation Research Record
References (1) ; Tables (9)
Old TRIS Terms:
Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control; I81: Accident Statistics
TRIS, TRB, ATRI
Apr 21 1993 12:00AM
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