Characteristics of nighttime pedestrian crashes: implications for headlighting

Abstract

Previous studies have shown that increased risk in the dark is particularly strong for pedestrian crashes, suggesting that attempts to improve headlighting should emphasize possible effects on those crashes. The current project was designed to provide information about how details of pedestrian crashes may differ between daylight and darkness. All pedestrian crashes that occurred in daylight or dark conditions in Michigan during 2004 were analyzed in terms of the variables included in the State of Michigan crash database. Additional analysis of the narratives and diagrams in police accident reports was performed for a subset of 400 of those crashes—200 sampled from daylight and 200 sampled from darkness. Several differences were found that appear to be related to the characteristic asymmetry of low-beam headlamps, which provide more light on the right than the left. These results provide preliminary quantification of the how the photometric differences between the right and left sides of typical headlamps may affect pedestrian crash risk.