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

In large cities, pedestrians account for 40% to 50% of traffic fatalities. Previous studies based on relatively small samples have concluded that Pedestrian Countdown Timers can reduce pedestrian crashes at signalized intersections. The purpose of the present study was to examine the effect of Pedestrian Countdown Timer (PCT) on crashes 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 over five-years; only when the PCT were introduced in large numbers was a consistent crash reduction observed. Because the magnitude of the crash reduction was shown to be a function of the extent to which the timers were introduced, the evidence for an intervention effect is strong. The results of the PCT statistical analysis provided unequivocal evidence that the pedestrian countdown timers reduced pedestrian crashes. The size of the effect in the Detroit sample was quite large (70% crash reduction). Like all treatments that target pedestrians, the installation of PCTs should be expected to produce the largest benefits in locations with very poor pedestrian safety compliance before installation. TRB 2014 Annual Meeting Original paper submittal not revised by author