Crash Modification Factors for Median Cable Barriers in Tennessee

This paper developed Crash Modification Factors (CMF) for median cable barriers in Tennessee. Utilizing cable barriers installed from 2006 to 2010, the study used comparison group approach that considers crashes before and after the installation of cable barriers. Comparison segments were selected if they met criteria such as median width equal to the median width of the existing cable barrier segment plus or minus 10 feet, the segment length is equal to the cable barrier segment plus or minus 20 feet and the AADT is equal to that of the cable barrier segment plus or minus 1000 vpd. Using comparison group and screened median-related crashes only, CMF for fatal crashes was found to be 0.04, fatal and incapacitating injury 0.07, and 0.14 for fatal and all injury crashes combined.. These CMFs which translate into crash reduction percentages of 96% and 86% for fatal and fatal and all injuries combined respectively are comparable or slightly better compared to those obtained from other states. However, when all crashes within the cable segment were used (without screening median related), the CMF for fatal was found to be 0.46, and 1.18 for all crashes. This implies that installation of cable barriers in Tennessee significantly reduces fatal and severe injury crashes but increase minor PDO crashes (mainly those below $400). The developed CMFs responds to the intended benefits of the median cable barriers to prevent cross-median crashes which occurs when a vehicle leaves its travel way enters or crosses the median dividing the highway directional lanes and collides with vehicles in the opposite direction.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ANB25 Standing Committee on Highway Safety Performance.
• Authors:
  • Bryant, Amber
  • Chimba, Deo
  • Ruhazwe, Evarist
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 13p

Subject/Index Terms

• TRT Terms: Crash modification factors; Fatalities; Median barriers; Traffic crashes
• Uncontrolled Terms: Cable barriers
• Geographic Terms: Tennessee
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01657939
• Record Type: Publication
• Report/Paper Numbers: 18-00225
• Files: TRIS, TRB, ATRI
• Created Date: Jan 25 2018 9:34AM