research >>identifying high-crash locations
in progress
Methods for Identifying High-Collision Concentration Locations for Potential Safety Improvements
The goal of the project is to enhance the California Department of Transportation's method for identifying places where crashes are concentrated. Tasks include:
- developing statistical models for generating expected collision risk based on observed frequency at a given location;
- utilizing existing information such as physical characteristics of the road segment to predict risk;
- weighting crashes by severity;
- considering variable segment lengths for highway analysis;
- considering extended roadway segments ("corridors with promise"); and
- screening for deterioration of safety over time.
High Collision Concentration Location: Table C Evaluation and Recommendations
This research is related to regularly published Caltrans reports, so-called Table C, that are used to screen for and investigate locations within the California State Highway System that have collision frequencies significantly greater than the base or expected numbers when compared to other locations. Main categories of findings:
- Physical structure of analysis units—what is a site?
- Temporal structure of analysis
- Choice of outcome(s)
- Criteria for selection of locations
- Format and content for reports
- data quality
- approaches other than site-specific approaches.
Resources
"Identification of High Collision Concentration Locations under Wet Weather Conditions" Taesung Hwang, Koohong Chung, David R. Ragland and Ching-Yao Chan. Poster presentation at TRB Annual Meeting, 2008.
"Comparison of collisions on HOV facilities with limited and continuous access during peak hours" Kitae Jan, Koohong Chung, David R. Ragland and Ching-Yao Chan. Poster presentation at TRB Annual Meeting, 2008.
"High Collision Concentration Location: Table C Evaluation and Recommendations:" Report to Caltrans. May 2007,
"Method for Generating Continuous Risk Profile for Highway Collisions" Koohong Chung, and David R. Ragland, Traffic Safety Center, Berkeley. Presentation at TRB Annual Meeting, 2007.