Actual versus estimated night-time pedestrian visibility

Abstract

The effects of headlight beams (high and low), glare and the use of a retroreflective tag by a pedestrian were studied simultaneously on the actual pedestrian night-time visibility distance and the pedestrian's estimate of his or her visibility distance. It was found that with a dark-clothed pedestrian for each of the visibility conditions studied (high beams, low beams and low beams + glare) the use of a retroreflective tag approximately doubled the pedestrian visibility distance. Furthermore, the tag invariably made the pedestrian visible at a distance greater than the stopping distance for a car travelling at 90 km/h. Most important, the pedestrian's estimate of his or her visibility distance also varied as a function of the same variables but in the case of high beams it was twice as far as the actual visibility and when the approaching car had its low beams on it was 1·4 times as far. Only in the presence of glare was the pedestrian's estimate of the visibility distance on average less than the actual visibility distance. Implications for night-time pedestrian safety are discussed.