INFLUENCE OF LIGHTING ON ACCIDENT FREQUENCY AT HIGHWAY INTERSECTIONS

Accident frequency for rural at-grade intersections was determined for 3-year periods immediately before and after lighting. Results from 47 intersections revealed a 49 percent overall reduction in night accidents after lighting. The average night accident rate per million entering vehicles was 1.89 before lighting and 0.91 after lighting, which is a reduction of 52 percent. This reduced night accident rate, when compared with the night accident rate before lighting and the day accident rate after lighting, is found to be statistically significant at the 99 percent level. Similar data are provided for groups of intersections for channelization, route turns, number of legs, number of lights, and average daily traffic.