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Journal of Advanced Transportation
Volume 2017, Article ID 5783696, 10 pages
Research Article

Analyzing Traffic Crash Severity in Work Zones under Different Light Conditions

1School of Materials Science and Engineering, Chang’an University, Xi’an, Shaanxi 710061, China
2Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA
3Construction Industry Research & Policy Center, Haslam College of Business, University of Tennessee, Knoxville, TN 37996, USA

Correspondence should be addressed to Xiang Shu; ude.ktu@uhsx and Huaxin Chen; moc.361@07029xhc

Received 6 March 2017; Revised 24 July 2017; Accepted 12 September 2017; Published 4 December 2017

Academic Editor: Helai Huang

Copyright © 2017 Xinxin Wei et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Previous studies have investigated various factors that contribute to the severity of work zone crashes. However, little has been done on the specific effects of light conditions. Using the data from the Enhanced Tennessee Roadway Information Management System (E-TRIMS), crashes that occurred in the Tennessee work zones during 2003–2015 are categorized into three light conditions: daylight, dark-lighted, and dark-not-lighted. One commonly used decision tree method—Classification and Regression Trees (CART)—is adopted to investigate the factors contributing to crash severity in highway work zones under these light conditions. The outcomes from the three decision trees with differing light conditions show significant differences in the ranking and importance of the factors considered in the study, thereby indicating the necessity of examining traffic crashes according to light conditions. By separately considering the crash characteristics under different light conditions, some new findings are obtained from this study. The study shows that an increase in the number of lanes increases the crash severity level in work zones during the day while decreasing the severity at night. Similarly, drugs and alcohol are found to increase the severity level significantly under the dark-not-lighted condition, while they have a limited influence under daylight and dark-lighted conditions.