Highway locations having an abnormal history of accidents should be identifiable in some way. Average and critical accident numbers and rates must be known for similar locations. Averages have been determined previously for rural highways, but it is necessary to update those numbers and to determine rates for urban areas. A detailed picture of traffic accidents in Kentucky in 1978 is presented. Average rates in terms of accidents per 100 million vehicle-miles (160 million vehicle-kilometers) were calculated for various classifications of rural and urban highways. Also, average rates in terms of accidents per million vehicles were determined for 0.3-mile (0.48-km) highway spots. Using these averages, critical accident rates were determined a...