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(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 0.688 | 31.2 |  | All | K | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.878 | 12.2 |  | All | A | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.84 | 16 | | All | B | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 1.006 | -0.6 | | All | C | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 1.23 | -23 | | All | O | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 1.144 | -14.4 | | All | All | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0 | 100 | | Cross median | K | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0 | 100 | | Cross median | A | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.266 | 73.4 | | Cross median | B | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.185 | 81.5 | | Cross median | C | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.569 | 43.1 | | Cross median | O | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.329 | 67.1 | | Cross median | All | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.414 | 58.6 | | Other | K | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.807 | 19.3 | | Other | A | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 0.795 | 20.5 | | Other | B | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 1.068 | -6.8 | | Other | C | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 2.601 | -160.1 | | Other | O | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
| 1.857 | -85.7 | | Other | All | Principal Arterial Interstate, Principal Arterial Other Freeways and Expressways | All |
