Performance Evaluation of a Cable Median Barrier System on an Oregon Highway with a Narrow Median

Abstract

The Mount Hood Highway (US-26) safety corridor in Oregon has historically experienced a high rate of crossover crashes resulting in fatalities and severe injuries. For much of the corridor, no physical barrier separates travel lanes from opposing traffic. Many locations have less than 4 ft of separation between opposing traffic. In an attempt to reduce crossover crashes on US-26, a cable median barrier (CMB) system was installed within a 1.5-mi segment in August 2007. The US-26 CMB is unique in that it is a nonfreeway application and in a narrow paved median. The US-26 CMB system may be the only CMB system in the United States that is on a nonfreeway in a median that is less than 8 ft wide. This study found that the US-26 cable median barrier system continued to prevent crossover crashes and to reduce crash severity. The results indicate that the section crash rate increased 72% following installation, a considerable amount. However, the fatal and injury crash rates declined by 29%, and the severity indicator for crashes in the CMB section decreased 59%. These changes suggest that although there has been an increase in crashes because of the installment of a fixed object in the middle of the road, the CMB has prevented more severe crashes such as head-on collisions. First responders and the state maintenance crew provided positive feedback for the narrow cable median barrier system.