Developing Crash Modification Factors to Quantify Impacts of Pedestrian Countdown Signals to Drivers

Pedestrian countdown signals (PCSs) are viable traffic control devices that assist pedestrians to cross intersections safely. Despite the fact that PCSs are meant for pedestrians, they also have an impact on driver behavior at intersections. This study focuses on evaluation of safety effectiveness of PCSs to drivers in the cities of Jacksonville and Gainesville, in Florida. A before-after study with empirical Bayes method was used in analyzing the vehicle crash data for the two cities, state maintained intersections with PCSs. Prior to establishing Crash Modification Factors (CMFs), full safety performance functions for different crash types and severities were estimated using the negative binomial regression model. From the predicted crash counts, the CMFs were established for distinctive categories of crashes based on crash severity types. The findings indicated that installing PCSs revealed a significant improvement of driver’s safety by 8.8% reduction in total crashes, 4.8% reduction in fatal and injury crashes, and 7.1% reduction in property damage only crashes. In addition, rear-end crashes were observed to be reduced by 8.0% whereas a 4.6% reduction in angle crashes was observed. Also, discussed in this study, are the crash modification functions (CMFunctions) showing the relationship between the developed CMFs and average daily traffic volume in the major street at the intersection were developed. In summary, the results suggest usefulness of PCSs for drivers.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ANB25 Standing Committee on Highway Safety Performance.
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Kitali, Angela E
    • Sando, Thobias
    • Castro, Angelicue
    • Kobelo, Doreen
    • Mwakalonge, Judith
  • Conference:
  • Date: 2017


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 14p
  • Monograph Title: TRB 96th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01626298
  • Record Type: Publication
  • Report/Paper Numbers: 17-05178
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 22 2017 9:55AM