Variables impacting the severity of crashes involving traffic barriers on horizontal curves: actual crash analysis of interstate roads in Wyoming

Abstract

Despite numerous past studies conducted on traffic barriers, research is still needed to analyze the performance of traffic barriers on superelevated horizontal curves. Based on the literature of traffic barrier studies, the effect of geometric features of traffic barriers (such as height and post-spacing) on crashes involving horizontal curves has not been investigated considering actual crash data analysis. This paper seeks to study the effect of various variables affecting the severity of traffic barrier crashes on horizontal curves. Geometric features of 95 miles of traffic barriers were collected, conducting a field inventory on all interstate roads in Wyoming. All the traffic barriers collected were located on horizontal curves with at least one historical crash report between 2008 and 2017. Random-parameters ordered logit was used to develop two models to investigate the factors impacting the severity of horizontal curve crashes involving side and median traffic barriers, respectively, on interstate roads. Based on the results, median box beam barriers with a post-spacing of 6.1 ft resulted in lower injury severity. Median W-beam barriers with a height taller than 31 inches were involved with a higher probability of severe collisions. Side box beam barriers located on the front side-slope were also more likely to increase the severity of crashes.