A Simulation-Based Study on the Integration of Vehicular Communication in Reducing Secondary Crashes in Congested Freeways

A considerable percentage of accidents on the highway occur as a result of traffic congestion induced by driver distraction triggered by the sight of a prior incident. Secondary crashes are defined as crashes that occur because of an original crash, either at the crash scene or inside the traffic queue or backup in either direction. Highway agencies are highly interested in establishing safety measures to reduce these types of incidents. Enabling the flow of information among vehicles allows motorists to proactively take precautions and approach traffic queues and accident sites more cautiously. Emerging technologies, including connected and autonomous vehicle technologies, can improve safety during incidents by facilitating communication between vehicles over an ad-hoc wireless vehicular network. Therefore, the objective of this study is to assess the potential impact of vehicular communication technology in mitigating the likelihood of further crashes during an incident on a heavily traffic highway. Our research was conducted based on the developed simulation modelling framework. Since crashes cannot be directly estimated from micro-simulation, we proposed a combination of the micro-simulation model VISSIM and the Surrogate Safety Assessment Model (SSAM) to capture vehicular conflicts. This approach allows us to measure vehicular conflicts as an indicator of the likelihood of secondary crashes. The results suggest that using connected vehicles (CVs) can be an effective method to reduce the probability of further accidents.