THE ABILITY TO SEE A PEDESTRIAN AT NIGHT: THE EFFECTS OF CLOTHING, REFLECTORIZATION AND DRIVER INTOXICATION*

ABSTRACT In the United States, pedestrian deaths account for nearly 20% of all traffic fatalities. During darkness the pedestrian's risk is increased. This risk is further increased if a pedestrian is wearing dark clothing or must travel on a roadway concurrently with a driver who has been drinking. In the laboratory phase of this study it was found that at low levels of illumination an individual's sensitivity to contrast decreases as his blood alcohol level increases. All subjects exhibited a significant (p <.01) decrease in contrast sensitivity at blood alcohol levels greater than 0.04%. In the road test phase of the study visibility distances were found to be unacceptably short for “dummy” pedestrians covered with black or gray fabric. Dummies covered with white fabric were safely visible for a driver traveling up to a speed of 50 M.P.H.; however, only reflectorized dummies were safely visible above that speed. At blood alcohol levels greater than 0.04% all of the observers exhibited a significant (p <.01) decrease in the mean visibility distance for each of the simulated pedestrian conditions.