1 Safety Effectiveness and Operating Performance of Three-Cable Median Barrier on Interstate 5 in Oregon

On interstate-type facilities, median crossover crashes are typically severe and often result in fatality or severe injury. Given the limited resources of most agencies, many transportation departments are interested in mitigating these crash types with the most cost-effective, proven countermeasure in the appropriate location. As a result, some states have installed a lower-cost solution, the three-cable median barrier, in areas with available median width and high crash potential. A literature review indicates there is limited information concerning the safety effectiveness and operating performance (maintenance and repair costs) of the cable barrier system. This paper presents the evaluation results of approximately 21.9 miles (35.2 kilometers) of cable barrier. The safety evaluation compared the before-and-after crash experience in the study location using three years of before-and-after computerized crash records. A statistically valid subset of similar interstate facilities in Oregon for use as a comparison group could not be identified for use in the study. As a result, this paper only reports a simple before-after study and economic comparison of the cost of the barrier system based on the crash severity. In addition, cable barrier impacts, under-rides, and penetrations were studied using maintenance records and police crash reports. The repair costs were also studied for the evaluation period. The study indicates that the cable barrier system has been effective in reducing the severity of crashes but, as expected, has resulted in an increase of reportable minor injury and property damage crashes