Reliability-Based Traffic Safety Risk Assessment of Traffic System in Hazardous Driving Conditions to Promote Community Resilience

For decades, work zone traffic safety under adverse weather conditions has been a serious concern for drivers and transportation agencies. Natural hazards often cause disruptions on roads and bridges and work zones during the retrofitting process. Existing studies on work zone traffic safety with statistical approaches are limited by the availability of data from historical crashes. To date, there is no comprehensive simulation framework to assess traffic safety on roads with work zones under adverse driving environments by considering both multi-vehicle and single-vehicle crashes. To fill this gap, this study presents an integrated framework to evaluate traffic safety in work zones under adverse driving conditions by considering specific work zone configuration, weather, and road surface conditions. A new risk index is introduced to assess the traffic safety risk of work zones by integrating the risks of multi- vehicle crashes and single-vehicle crashes. Traffic safety of a typical work zone under different weather conditions is studied to demonstrate the proposed framework. The impacts of the differential speed limits (DSL) and truck proportions on work zone traffic safety are also investigated. Results show that adverse weather may increase the crash risk in work zones. The effect of DSLs on work zone traffic safety is found to be insignificant, while truck ratio influences work zone safety in rainy and snowy weather by primarily affecting multi-vehicle crash risks.