Pedestrian Visibility at Night: Effects of Pedestrian Clothing, Driver Age, and Headlamp Beam Setting

ABSTRACT Reduced visibility is believed to be a major contributor to night-time pedestrian fatalities. In thisstudy, the ability of drivers to recognize the presence of roadside pedestrians was determined andrecognition distances measured using a parallax-based device. Ten young and ten older participants drove atnight around a closed road circuit and pressed a button whenever they recognized a pedestrian. Fourpedestrian clothing conditions were tested (black, white, retroreflective vest and retroreflective material inthe ‘biomotion’ configuration) in both low and high beam conditions. Two pedestrians walked in place onthe shoulder of the road, one in darkness (primary) and one in a high glare position (secondary). Responsedistances were recorded for the primary pedestrian. Overall, drivers identified only 61% of pedestrians inthe presence of glare and 76% in the absence of glare, with only 5% of darkly clad pedestrians beingidentified in the glare condition. Averaged across conditions, the primary pedestrian was identified at 76.5m(251ft), with distances being shortest for darkly clad pedestrians (13m (43ft)), and greatest for the‘biomotion’ pedestrian condition, which improved response distances by up to 50X. The vest conditionfailed to produce similar benefits, despite having an equivalent amount of retroreflective material. Overall,older driver response distances were 58% of those of the younger drivers. These results demonstrate thatwhile all drivers have significant difficulty recognizing pedestrians at night, elderly drivers experience evengreater difficulty. The results also demonstrate the value of clothing configurations that enhance theperception of biological motion.