Estimating safety benefit of in-vehicle work zone safety technology alerts: A counterfactual Monte-Carlo simulation approach

Work Zone Safety Technologies (WSTs) have exhibited great potential to improve road work zone safety by detecting safety risks and providing warnings to drivers and workers involved. Yet, it remains extremely challenging to quantify the actual safety benefits of such technologies in reducing work zone intrusion accidents, mainly due to a lack of empirical data and robust evaluation methods. This paper aims to explore the patterns of drivers' behavioural responses when approaching work zones and estimate the safety benefits of in-vehicle WSTs. First, a VR-based driving simulation experiment was conducted to collect human behavioural data on drivers' responses when approaching work zones in critical scenarios. Second, a Linear Mixed Effect (LME) model was developed to capture the impact of in-vehicle WST alerts and scenario criticality, i.e., speed and Time-to-Collision (TTC), on drivers' behavioural responses. Finally, the safety benefits of in-vehicle WST alerts were estimated through counterfactual Monte-Carlo simulations of vehicle trajectories. The findings highlight the mechanism by which in-vehicle WST alerts improve driver response in various critical driving scenarios involving work zones and provide crucial evidence for future decision-making regarding the evaluation of WSTs.