Role of Expectancy, Motion and Overhead Lighting on Nighttime Visibility

Abstract

More than half of the pedestrian fatalities occur at night. It is important to understand the factors that lead to pedestrian detection for designing and implementing effective countermeasures in order to reduce pedes-trian fatalities. Research has shown that expectancy, motion and overhead lighting affect pedestrian visibil-ity. This goal of this study is to understand the combined effect of these three factors on nighttime visibil-ity. Twenty four participants were recruited to drive on a test track under different conditions of expectancy and overhead lighting. The participants were asked to identify static and moving objects. The results showed that as the level of expectancy increases the detection distances also increase. Moving objects were detected from farther than static objects and presence of overhead lighting also increased the detection dis-tances. Motion tends to draw more attention than expectancy when detecting new objects. These results have implications in the areas of pedestrian safety, novice driver training and work zone safety. They also reiterate the safety benefits of providing overhead lighting at high pedestrian-vehicle conflict areas.