Pedestrian Conspicuity at Night: The Effects of Retroreflector Placement and Retroreflection

One factor that has been causally linked to nighttime pedestrian-vehicle collisions is pedestrians being insufficiently conspicuous to drivers. Pedestrian conspicuity can be enhanced by use of retroreflective material, and this on-road experiment investigated the influence of retroreflector configuration, the coefficient of retroreflection (RA) of those retroreflectors, and pedestrian motion on conspicuity. There were two retroreflector configurations, three levels of RA, and the test pedestrian either walked or stood in place. Data from 121 participants are reported. The pedestrian was detected by more participants and at greater distances when the pedestrian was walking and wearing retroreflectors on the wrists and ankles (W+A). Response distances to the walking pedestrian wearing the W+A configuration increased as R A increased. Increasing RA did not, however, increase response distances to the standing pedestrian wearing the W+A configuration, the standing pedestrian wearing the torso configuration, or the walking pedestrian wearing the torso configuration. These results suggest that RA may increase pedestrian conspicuity when biological motion information is present but RA may not increase pedestrian conspicuity when biological information is not present.