Evaluating the Effectiveness of Urban Speed Cameras on Traffic Safety in a Period of Dramatic Change

This report employs Bayesian negative binomial and Poisson models to examine the effectiveness of speed cameras at reducing crashes, injuries, and fatalities on and immediately around Roosevelt Boulevard, a particularly dangerous urban arterial in Philadelphia, Pennsylvania. Camera installation also coincided with rapidly changing traffic safety outcomes throughout the summer after COVID-19 lockdowns and protests against police violence. To find the most appropriate control segments for the analysis, the authors use k-means clustering to identify the five most similar roadways. Compared to these roadways and other geographic controls, the treated sections of Roosevelt Boulevard experienced decreased crashes, injuries, and fatalities after camera installation. These decreases are on the high end of what is found in the academic literature on speed cameras. The findings for total crashes, traffic injuries, fatalities, and pedestrian injuries are statistically different from zero with a high degree of confidence. Differences in pedestrian fatalities are statistically different from zero with 90%. Based on their findings, the authors recommend that the Commonwealth of Pennsylvania and City of Philadelphia extend and expand the automated speed enforcement pilot. Estimates of the economic benefits of reduced crashes substantially exceed the total fines paid by violators. Despite this positive safety effect, additional treatments will be required to make Roosevelt Boulevard substantially safer. The roadway still accounts for around 8% of all traffic fatalities in Philadelphia.

• Record URL:
  • https://ppms.cit.cmu.edu/media/project_files/Guerra_Erick_420.pdf
• 
• Summary URL:
  • https://ppms.cit.cmu.edu/projects/detail/420
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/77494
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  Carnegie Mellon University

  Pittsburgh, PA  United States 

  Safety21 University Transportation Center

  Carnegie Mellon University
  Pittsburgh, PA  United States  15213

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Guerra, Erick
  • 0000-0002-7769-2581
• Publication Date: 2024-7-31

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Research Report
• Features: Appendices; Figures; Maps; References; Tables;
• Pagination: 24p

Subject/Index Terms

• TRT Terms: Before and after studies; Cameras; Crash rates; Crash severity; Fatalities; Pedestrian safety; Traffic safety; Traffic speed
• Geographic Terms: Philadelphia (Pennsylvania)
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01931612
• Record Type: Publication
• Contract Numbers: 69A3552344811; 69A3552348316
• Files: UTC, NTL, TRIS, USDOT
• Created Date: Sep 23 2024 9:05AM