Development of Crash Modification Factors (CMFs) for Utah Intersections

This research project aims at developing state-specific CMFs at intersections in Utah to quantify the safety impact of the countermeasures. Considering the research needs, data availability, and suggestions from the Technical Advisory Committee, the CMFs of four left-turn-phasing-related treatments, namely converting both-roadway permissive to one-roadway permissive-protected left-turn phasing, converting one-roadway to both-roadway permissive-protected left-turn phasing, converting both-roadway permissive-protected to one-roadway protected left-turn phasing, and converting one-roadway to both-roadway protected left-turn phasing are developed using the cross-sectional study. The results revealed that the conversion from permissive to permissive-protected left-turn signals showed no improvement in safety. However, converting permissive-protected signals to protected signals did result in a reduction of left-turn-related crashes. The CMF estimates for converting to protected left-turn phasing align with findings from other states, but CMFs for converting to permissive-protected phasing are higher than those seen in other states. A survey of other state DOT practices of permissive-protected left-turn phasing indicates that Utah typically uses a shorter protected portion of the permissive-protected phasing compared to other states which may be a possible reason for why Utah’s CMFs are higher.

• Record URL:
  • https://drive.google.com/file/d/1o8dTkD8ZABer6UJDAjOI-q5bm69gb71_/view
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/68822
• Corporate Authors:

  University of Utah

  Department of Civil and Environmental Engineering
  110 Central Campus Drive Suite 2000
  Salt Lake City, UT  United States  84112

  Utah Department of Transportation

  4501 South 2700 West
  Salt Lake City, UT  United States  84114-8410

  U.S. Department of Transportation

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Gong, Yaobang
  • Yang, Xianfeng Terry
• Publication Date: 2023-2

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Maps; References; Tables;
• Pagination: 80p

Subject/Index Terms

• TRT Terms: Alternatives analysis; Crash modification factors; Highway safety; Left turn phase; Phasing by right of way; Signalized intersections
• Identifier Terms: Utah Department of Transportation
• Geographic Terms: Utah
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01894147
• Record Type: Publication
• Report/Paper Numbers: UT-23.13
• Contract Numbers: 22-8288
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Sep 22 2023 9:08AM