Effects of Intersection Lighting Design on Nighttime Visual Performance of Drivers

ABSTRACT

Nighttime crashes at intersections present a major traffic safety issue in the United States. Existing approaches to intersection lighting design do not account for a driver’s visual performance or the potential interactive effects of vehicle headlamps and roadway lighting. For effective design lighting at intersections, empirical research is required to evaluate the effects of lighting configuration (part of the intersection illuminated) and lighting levels on nighttime driver visual performance. The current study had two goals: First, to quantify visual performance in three lighting configurations (illuminating the intersection box, approach, or both) and second, to determine what lighting levels within each lighting configuration support the best visual performance. The study involved a target detection task completed at night on a realistic roadway intersection. Illuminating the intersection box led to superior visual performance, as indicated by longer target detection distances, fewer missed targets, and more targets identified within a safe stopping distance. For this lighting configuration, visual performance plateaued between 7 and 10 lx of mean intersection illuminance. These results have important implications for the design of intersection lighting at isolated/rural intersections, specifically that illuminating the intersection box is an effective strategy to increase nighttime visual performance for a wider range of driver ages and could also be an energy-efficient solution.

KEYWORDS:

• Intersection lighting design
• intersection lighting design standards
• isolated intersections
• night driving
• rural intersections
• safety
• visual performance

Funding

Funding for this research was provided by the National Surface Transportation Safety Center for Excellence (NSTSCE). NSTSCE at VTTI develops and disseminates advanced transportation safety techniques and innovations. The mission of the Center is to use state-of-the-art facilities, including the Virginia Smart Road, to conduct the research necessary to improve driver safety in both rural and urban communities. Stakeholders of NSTSCE include the Federal Highway Administration, Federal Motor Carrier Safety Administration, VDOT and the Virginia Center for Transportation Innovation and Research, General Motors Corporation, and Travelers Insurance.

Additional information

Funding

Funding for this research was provided by the National Surface Transportation Safety Center for Excellence (NSTSCE). NSTSCE at VTTI develops and disseminates advanced transportation safety techniques and innovations. The mission of the Center is to use state-of-the-art facilities, including the Virginia Smart Road, to conduct the research necessary to improve driver safety in both rural and urban communities. Stakeholders of NSTSCE include the Federal Highway Administration, Federal Motor Carrier Safety Administration, VDOT and the Virginia Center for Transportation Innovation and Research, General Motors Corporation, and Travelers Insurance.