Investigation of Factors Affecting Crash Severity of Rear-End Crashes With High Collision Speeds in Work Zones: A South Carolina Case Study

The aim of this study is to identify factors that affect injury severity levels of work zone rear-end crashes with high collision speeds (35 mi/hr). Using statewide crash data provided by the South Carolina Department of Transportation from 2014 to 2020, a mixed binary logit model with heterogeneity in mean and variance is estimated. The model’s outcome variable is injury or non-injury (i.e., property damage only), and the explanatory variables include information related to vehicle, collision, time, occupant, roadway, and environmental characteristics. The estimation results indicate that the interstate variable is best modeled as a random parameter at 90% confidence level. Late-night and dawn/dusk conditions are found to influence the mean effect while driving under the influence has an effect on the variance of the random parameter. The factors that positively influence injury severity are multi-vehicle involvement, airbag deployment, dark conditions, and crashes involving trucks. Conversely, advanced warning area, activity area, lane shift/crossover, young and middle-aged drivers, and dawn/dusk conditions have negative effects on injury severity.