Evaluation of the Influences of Cable Barrier Design and Placement on Vehicle to Barrier Interface

The main aim of longitudinal safety barriers, such as cable barriers, is to contain and/or redirect errant vehicles that depart the roadway, hence keeping them from entering opposing travel lanes or encountering terrain features and roadside objects that may cause severe impacts. In this paper, vehicle dynamics analysis is used to study the effect of median configuration and cable barrier designs on safety performance. Median configurations vary by width, side slope and slope configurations, and cross section. Cable designs for this effort considered the number, arrangements, and height. Vehicle dynamics analyses were conducted to compute the vehicle trajectory and dynamics as the vehicle crosses the sloped terrain and interfaces with the barrier. Vehicle dynamics analysis allowed a range of vehicles and impact conditions to be studied. The various plots generated provide insights: on the optimal placement locations for 3- or 4-cable systems; on the differences between degree of slope, cross section shape, and median width; and on varying impact conditions. The data generated provides a robust basis for the development of improved guidelines for median barrier design and placement.