Citation

Mehrara Molan A, Moomen M, Ksaibati K. J. Saf. Res. 2019; 71: 163-171.

Affiliation

Wyoming Technology Transfer Center, Department of Civil & Architectural Engineering, University of Wyoming, 1000 E. University Avenue, Dept. 3295, Laramie, WY 82071, United States. Electronic address: khaled@uwyo.edu.

Copyright

(Copyright © 2019, U.S. National Safety Council, Publisher Elsevier Publishing)

DOI

10.1016/j.jsr.2019.10.001

PMID

31862027

Abstract

INTRODUCTION: Despite the numerous safety studies done on traffic barriers' performance assessment, the effect of variables such as traffic barrier's height has not been identified considering a comprehensive actual crash data analysis. This study seeks to identify the impact of geometric variables (i.e., height, post-spacing, sideslope ratio, and lateral offset) on median traffic barriers' performance in crashes on interstate roads.

METHOD: Geometric dimensions of over 110 miles median traffic barriers on interstate Wyoming roads were inventoried in a field survey between 2016 and 2018. Then, the traffic barrier data collected was combined with historical crash records, traffic volume data, road geometric characteristics, and weather condition data to provide a comprehensive dataset for the analysis. Finally, an ordered logit model with random-parameters was developed for the severity of traffic barrier crashes. Based on the results, traffic barrier's height was found to impact crash severity.

RESULTS: Crashes involving cable barriers with a height between 30″ and 42″ were less severe than other traffic barrier types, while concrete barriers with a height shorter than 32″ were more likely involved with severe injury crashes. As another important finding, the post-spacing of 6.1-6.3 ft. was identified as the least severe range in W-beam barriers. PRACTICAL APPLICATIONS: The results show that using flare barriers should reduce the number of crashes compared to parallel barriers.

Copyright © 2019 National Safety Council and Elsevier Ltd. All rights reserved.

Language: en

Keywords

Crash severity; Median traffic barrier; Random parameters ordered logit; Traffic barrier dimensions; Wyoming