Safety Benefits and Best Practices for Intersection Lighting

About the report:

Nighttime safety continues to be a major concern for transportation agencies across the country. Roadway lighting has been widely used as a countermeasure for nighttime crashes. However, safety engineers and researchers frequently lack effective tools when determining exactly how lighting should be optimized to maximize safety while conserving energy. This project involved an extensive effort to investigate traffic safety lighting impacts at intersections. Based on the results, the project identified optimal lighting levels for different types of intersections and developed guidelines to facilitate lighting needs analysis and design at the Virginia Department of Transportation. During this study, a crash analysis showed a 2.9% reduction in night-to-day crash ratio for each 1-lux increase of minimum illuminance at intersection boxes. Additionally, the project team found a benefit-cost ratio between 2.6 and 5.6 for unsignalized intersections and between 2.8 and 7.9 for signalized intersections, assuming one injury nighttime crash per year at such locations and depending on whether existing poles can be used.

Authors