Study Details

Study Title: Safety Effectiveness of Cable Median Barriers in Louisiana

Authors: Mitran et al.

Publication Date: SEP, 2023

Abstract: The primary objective of this research was to investigate the safety effectiveness of cable median barriers (CMB) installed on Louisiana freeway medians. This study performed a comprehensive evaluation to ascertain the performance of CMB from traffic safety and economic standpoints. A three-year observational before-and-after crash analysis for total and targeted crashes (by severity, manner of collision, testing level, and other relevant factors) was conducted for 23 CMB segments consisting of 275 miles throughout the state. Furthermore, crash modification factors were developed to better understand the impact of CMB on crash outcomes. Finally, a comprehensive benefit-cost analysis was performed to assess CMB’s cost-effectiveness. The results revealed that cross-median crashes for all severity levels and head-on crashes significantly decreased after CMB implementation (100% reduction for fatalities and serious injuries). Median-related fatal and serious injury crashes also decreased significantly. However, an increase in property damage only (PDO) crashes was observed in the cases of total and median-related crashes. The benefit-cost ratios calculated using economic crash unit costs for both total and targeted crashes were higher than one. Notably, when using the comprehensive crash unit costs, the estimated benefit-cost ratios were considerably greater. The CMB were found to be effective in reducing cross-median crashes and mitigating crash severities. They were also proven to be cost-effective countermeasures despite the increase in PDO crashes, justifying the continuous use of CMB in Louisiana.

Study Citation: Mitran, E., X. Sun, and S.J. Ahmed. "Safety Effectiveness of Cable Median Barriers in Louisiana." Report No. FHWA/LA.23/684. Louisiana Department of Transportation. Baton Rouge, Louisiana. (2023).

Related Citations: Ahmed, S.J., M.A. Rahman, E. Mitran, X. Sun, and Z.S. Shorna. "Investigating safety and cost-effectiveness of cable median barriers in Louisiana." Traffic Injury Prevention, Volume 25, Issue 3, (2024).

Study Report: Download the Study Report Document


CMFs Associated With This Study

Category: Roadside

Countermeasure: Install cable median barrier

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.68831.23 StarsAllKPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.87812.22 StarsAllAPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.84163 StarsAllBPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
1.006-0.63 StarsAllCPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
1.23-233 StarsAllOPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
1.144-14.43 StarsAllAllPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
01002 StarsCross medianKPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
01002 StarsCross medianAPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.26673.43 StarsCross medianBPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.18581.53 StarsCross medianCPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.56943.13 StarsCross medianOPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.32967.13 StarsCross medianAllPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.41458.63 StarsOtherKPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.80719.32 StarsOtherAPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
0.79520.53 StarsOtherBPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
1.068-6.83 StarsOtherCPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
2.601-160.13 StarsOtherOPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll
1.857-85.73 StarsOtherAllPrincipal Arterial Interstate, Principal Arterial Other Freeways and ExpresswaysAll