Methods for Identifying High Collision Concentrations for Identifying Potential Safety Improvements: Development of Safety Performance Functions for California

This research developed Type 1 and Type 2 safety performance functions (SPFs) for roadway segments, intersections and ramps on the entire California Department of Transportation (Caltrans) network. Type 1 SPFs involved statistical models with a length offset, and average daily traffic (ADT) while Type 2 SPFs included geometrics as well. In the case of intersections, Type 2 SPFs included traffic control, ADT and roadway geometrics. For ramps, Type 2 SPFs included variables related to metering, HOV lane presence and ramp configuration. The research developed SPFs using data based on the period 2005-2010, and tested the SPFs on the period 2011-2012. Type 1 and Type 2 SPFs were compared for predictive effectiveness, and it was found that Type 2 SPFs provided for better measures of effectiveness such as mean absolute deviation, mean absolute percent error and mean squared error.

• Record URL:
  http://www.dot.ca.gov/research/researchreports/reports/2015/CA15-2317_FinalReport.pdf
• Record URL:
  https://merritt.cdlib.org/d/ark%3A%2F13030%2Fm5962ck5/1/producer%2FCA15-2317.pdf
• 
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/922079483
• Corporate Authors:

  University of California, Berkeley

  Institute of Transportation Studies
  McLaughlin Hall
  Berkeley, CA  United States  94720

  California Department of Transportation

  Division of Research, Innovation and System Information
  1727 30th Street, MS 83
  Sacramento, CA  United States  95816
• Authors:
  • Shankar, Venky
  • Madanat, Samer
• Publication Date: 2015-1-31

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Tables;
• Pagination: 114p

Subject/Index Terms

• TRT Terms: Geometric segments; High risk locations; Highways; Intersections; Measures of effectiveness; Ramps; Statistical analysis; Traffic volume
• Identifier Terms: Safety Performance Functions
• Geographic Terms: California
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01577589
• Record Type: Publication
• Source Agency: UC Berkeley Transportation Library
• Report/Paper Numbers: CA15-2317
• Contract Numbers: 65A0485
• Files: CALTRANS, TRIS, ATRI, STATEDOT
• Created Date: Sep 30 2015 9:08AM