An Empirical Assessment on the Effects of Geometry and Non-Geometry Factors in Work-Zone Crashes With Unobserved Heterogeneity

Work zones are uniquely configured and managed by special traffic signs, standard channelizing devices, appropriate barriers, and pavement markings. Unexpected driving conditions through different work-zone configurations may potentially cause risks for drivers. Using data from Florida for 2012 to 2017, driver injury severities in single-vehicle work-zone crashes were studied using random parameters logit models that allow for possible heterogeneity in the means and variances of parameter estimates. The available data include a wide variety of factors known to influence driver injury severity, including data related to the crash characteristics, vehicle characteristics, roadway attributes, prevailing traffic volume, driver characteristics, and spatial and temporal characteristics. The estimated models produced significantly different parameters for work-zone crashes due to geometry-related and non-geometry-related factors, suggesting a complex interaction. In several key instances, the marginal effects of individual parameter estimates show marked differences between these two scenarios. The model estimation findings add to the growing body of literature that suggests that geometric restrictions inside work zones pose a different set of risk factors in work-zone crashes from non-geometry-related factors. The notion of geometric restrictions, apart from normal driving conditions, could have profound effects on the safety performance of geometric configurations of work zones as well as various training opportunities for crash scene investigators to identify accurate contributing factors.