BIOLOGICAL MOTION AND NIGHTTIME PEDESTRIAN CONSPICUOUSNESS

Two experiments were conducted in the laboratory to evaluate potential benefits of different retroreflective markings for nighttime pedestri an visibility. Video recordings of a jogger wearing four different mar kings were made from a vehicle in four different road environments. Su bjects viewed composite tapes that included each of the 16 jogger mark ing/road environment combinations as well as travel with no targets. T he task was to step on a pedal immediately upon seeing a jogger, which had no effect on the flow of the video playback. The time between dep ression of the pedal and the point of ''impact'' was the major depende nt variable. Experiment 1 showed that performance was better for all r etroreflective markings than for the dark control and that it was bett er with markings of the limbs than of the torso. Experiment 2, which i ncluded a secondary video tracking task, showed that performance was b etter for markings that incorporate biological motion than for a vest or arbitrarily positioned stripes on the limbs. Questionnaire data ind icated that 85% of the subjects judged the biological motion markings to be ''easiest to see.'' Also, subjects reported more conservative es timates of nighttime visibility and greater willingness to take person al precautions at night after participating in the experiment.