Abstract
Most collisions between vehicles and pedestrians occur at night. This experiment quantified the ability of drivers to detect pedestrians at night. Ten younger (M=27.8 yrs) and ten older (M=67.9 yrs) participants drove an instrumented car ten laps around an unilluminated 1.1 mile test track. Drivers pressed a dash-mounted touchpad when they recognized the presence of a pedestrian. A computer-based system measured recognition distances by interpreting the parallax provided by two synchronized digital video cameras mounted on the car's roof. Two pedestrians walked in place at different positions on the far shoulder. One pedestrian was in darkness and one was positioned just beyond a stationary pair of headlights that was a source of glare for the approaching driver. Across laps, drivers used both low and high beams and pedestrians wore four different clothing configurations. The effects of age, glare, clothing, and beam all significantly influenced both pedestrian identification (all p < .01) and recognition distance (all p < .001). With and without glare, older drivers identified only 48% and 59% of the pedestrians, respectively. Younger drivers identified significantly more pedestrians (75% with glare, 94% without glare). Recognition was worst for pedestrians wearing black (34% identified). Only 5% of drivers identified the black-clad pedestrian when the driver used low beams and faced glare. Recognition was best (94% identified) for pedestrians wearing retroreflective markings configured to depict biological motion. Analysis of the recognition distances revealed that when identification occurs it is often at a distance insufficient to allow a successful avoidance maneuver. Taken together, these data confirm that even alerted drivers can have great difficulty recognizing the presence of pedestrians at night. The problem is greatest for older drivers, when drivers rely on low beams, when pedestrians wear low reflectance clothing, and when glare is present.