An Analysis of The Effects of Installing Pedestrian Countdown Timers on the Incidence of Pedestrian Crashes in the City of Detroit Michigan

摘要

In large cities, pedestrians account for 40% to 50% of traffic fatalities. Previousstudies based on relatively small samples have concluded that Pedestrian CountdownTimers can reduce pedestrian crashes at signalized intersections. The purpose of thepresent study was to examine the effect of Pedestrian Countdown Timer (PCT) oncrashes in a large city with a long baseline and relatively patterned introduction of PCTs.No general drop-off in crash frequency was found throughout a baseline interval of overfive-years; only when the PCT were introduced in large numbers was a consistent crashreduction observed. Because the magnitude of the crash reduction was shown to be afunction of the extent to which the timers were introduced, the evidence for anintervention effect is strong. The results of the PCT statistical analysis providedunequivocal evidence that the pedestrian countdown timers reduced pedestrian crashes.The size of the effect in the Detroit sample was quite large (70% crash reduction). Likeall treatments that target pedestrians, the installation of PCTs should be expected toproduce the largest benefits in locations with very poor pedestrian safety compliancebefore installation.