Development of Crash-Severity-Index Models for the Measurement of Work Zone Risk Levels

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Safety Science

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DOI: 10.1016/j.aap.2008.06.012


Highway work zones interrupt regular traffic flows and create safety problems. Improving safety without sacrificing the main function of highways is a challenging task that traffic engineers and researchers have to confront. In this study, the concept of using crash severity index (CSI) for work zone safety evaluation was proposed and a set of CSI models were developed through the modeling of work zone crash severity outcomes. A CSI is a numerical value between zero and one that is estimated from given work zone variables. It is interpreted as the likelihood of having fatality/fatalities when a severe crash occurs in a given work zone. The CSI models were developed using a three-step approach. First, a wide range of crash variables were examined in a comprehensive manner and the significant risk factors that had impact on crash severity were selected. Second, the CSI models were developed using logistic regression technique by incorporating the selected risk factors. Finally, the developed models were validated using the recent crash data and their ability in assessing work zone risk levels were analyzed. Results of this study showed that CSI models can provide straightforward measurements of work zone risk levels.


Accepted version. Safety Science, Vol. 40, No. 5 (September 2008): 1724-1731. DOI. © 2008 Elsevier. Used with permission.

Yong Bai was affiliated with University of Kansas at the time of publication.

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