Ultraviolet Headlamp Technology for Nighttime Enhancement of Roadway Markings and Pedestrians

Motorists driving at night are two to three times more likely to be involved in a crash than during the day. Although, about half of the motor vehicle deaths occur at night, death rates based on miles driven are about four times higher at night than during the day. Nighttime driving also frustrates a large number of people, the majority of which are seniors. There is an effort under way to evaluate the use of supplemental ultraviolet (UV) automobile headlights to increase nighttime visibility. Research conducted in Sweden has shown very promising results, and a preliminary field research effort recently completed in the United States found that the visibility of pavement markings increased 25 percent with UV, and subjects generally favored its use. An extensive field study was conducted to determine the conditions under which driver performance could be improved with fluorescent traffic control devices and auxiliary UV headlights. Several static tests were done to evaluate fluorescent pavement markings, post-mounted delineators, and various pedestrian scenes under two headlight conditions (low beam only and low beam with UV). Dynamic tests included a subjective evaluation of two headlamp conditions and a performance test in which subjects drove an instrumented vehicle. The results of the field study indicated that pavement markings could be observed 30 percent further, and pedestrians could be observed over 90 percent further with the addition of UV. Subjects consistently evaluated the use of UV headlamps as beneficial.