Using Crash Modification Factors To Appraise The Safety Effects Of Pedestrian Countdown Signals For Drivers

Although pedestrian countdown signals (PCSs) are meant for pedestrians, they give cues to drivers on the remaining amount of green as the timer counts down. This study focuses on the evaluation of safety effectiveness of PCSs to drivers in the cities of Jacksonville and Gainesville, Florida, using the before-after study with the empirical Bayes method. This analysis explored 110 intersections with PCSs and their respective 93 comparison sites. The findings indicate that PCSs significantly improve driver safety by 8.8% reduction in total crashes, 8.0% in rear-end and 7.1% in property-damage-only crashes, where both of these results were significant at the 95% confidence level. Results for angle crashes as well as fatal and injury crashes were not significant at the 95% confidence level. Also discussed in this study are the crash modification functions developed to show the relationship between the estimated crash modification factors and total entering traffic volume at the intersection. In summary, the results suggest the usefulness of PCSs for drivers. (C) 2018 American Society of Civil Engineers.