Estimating the effect of geometric features of side traffic barriers on crash severity of interstate roads in Wyoming. (September 2020)

• Record Type: Journal Article
• Authors: Molan, Amirarsalan Mehrara; Moomen, Milhan; Ksaibati, Khaled
• Is Part Of: Accident analysis and prevention. Volume 144(2020)
• Publication Date: 2020-09
• Subjects: Side traffic barrier -- Traffic barrier geometric features -- Crash severity -- Roadside safety -- Interstate roads; Accidents -- Prevention -- Periodicals; Accident Prevention -- Periodicals; Accidents -- Prévention -- Périodiques; 363.106
• DOI: 10.1016/j.aap.2020.105639
• Languages: English
• ISSNs: 0001-4575

Abstract

Highlights: Geometric features of over 150 miles of side traffic barriers were collected by conducting a field inventory on interstate roads. A statistical model was developed for the severity of crashes involving side traffic barriers using random-parameters ordered logit models. Box beam barriers with a height between 29 and 31 in. resulted in a lower crash severity compared to other side traffic barriers. Side box beam barriers with a post-spacing of 6.1−6.3 ft were least likely to result in high-severity crashes. Abstract: Past roadside safety studies mostly evaluated the impact of traffic barrier geometric features using simulation tools or by conducting field crash tests. While past simulation and field crash tests could present important findings for upgrading the geometric design of traffic barriers, there is still a gap regarding conducting an actual data analysis on side traffic barriers crashes with regards to their geometric dimensions. This paper aims at filling this gap by combining a statewide dataset of side traffic barrier geometric features with historical crashes on interstate roads in Wyoming. Therefore, geometric features including system height, post-spacing, lateral offset (from the edge of pavement), and side-slope of over 150 miles of side traffic barriers were inventoried by conducting a field survey on interstate roads in Wyoming. For the statistical analysis, a random-parameters ordered logit model was utilized to investigate variables impacting crash severity of side traffic barriers. It was found that system height could significantly impact the crash severity of side box beam barriers. Box beam barriers with a system height between 25 and 31 in. were identified to be less severe in comparison to other height categories, while showing minimum risks of severe crashes in the system height of 29−31 in.. On the other hand, box beam barriers with a height taller than 31 in. may increase crash severity.