Cable Median Barrier Failure Analysis and Remediation Phase II
Cody Stolle, Dean Sicking, Ronald Faller, John Reid
On divided roadways, cross-median fatalities are disproportionately overrepresented in fatal and serious injury crashes. Many state DOTs sought to mitigate cross-median crash risk by installing cable median barriers. Despite increased crash rates, studies evaluating crash rates before and after cable median barriers were installed indicated excellent improvement in overall safety. Nonetheless, cable barriers can also contribute to serious injury and fatality crashes which would not have otherwise occurred, including penetration and rollover crashes. A study was conducted to evaluate the conditions associated with severe cable median barrier crashes. While average penetration and rollover rates were 9.3 and 5.1%, respectively, penetration rates for passenger cars exceeded 15%, while rollover rates for pickups and SUVs was approximately 13%. Generally, vehicles with low bumper heights, high CG heights, and higher masses were involved in statistically significantly more cable median barrier penetrations. CG trajectory angles leading up to impact with the barriers were analyzed, and the 85th percentile trajectory angle associated with severe cable median barrier crashes was 39 degrees. Additional factors contributing to cable median barrier penetrations and rollovers were identified and summarized, and updates to cable barrier crash tests were recommended to improve system performance.
Highway Safety, Cable Barriers, In-Service Performance, Barrier Failures, Crash Test Criteria