Traffic management implications of Cooperative Automated Vehicles mixed with Regular Vehicles on motorways

<p>Automated vehicles (AVs) are rapidly evolving and have gained increasing attention from researchers due to their tremendous traffic management and safety advantages. While several studies discussed the implications of Cooperative Adaptive Cruise Control (CACC) technologies for capacity, few had a comprehensive approach to the impacts of CACC-equipped vehicles (Cooperative AVs) on motorway traffic management and sustainability. According to both NHTSA and SAE, CACC is considered level 1 automation. Nonetheless, the performance of CACC vehicles under each scenario can be demonstrative of the performance at higher automation levels. This paper evaluates the impacts of Cooperative AVs on motorway traffic capacity, speed, and ecological sustainability, comparing them against Regular Vehicles (RVs). A micro-simulation model in PTV VISSIM was developed to analyze the interaction of Cooperative AVs and RVs in interurban traffic scenarios. The study assessed the impact of Cooperative AVs on critical traffic metrics, including capacity, speed, flow, vehicle delay, and CO₂ emissions. Various penetration levels of Cooperative AVs (0%, 20%, 40%, 80%, and 100%) were evaluated in a mixed traffic environment alongside RVs. Results showed that Cooperative AVs significantly improve traffic performance. At full penetration, road capacity increased by 85%, average speed by 65%, and traffic flow by 80%. Additionally, vehicle delays were reduced by 75%, and CO₂ emissions decreased by 40%, underscoring both traffic efficiency and ecological benefits. These findings highlight the potential of Cooperative AVs to transform motorway traffic management by improving flow and sustainability. However, challenges remain, including the unpredictability of human drivers, mixed traffic complexities, and the need for advanced Vehicle-to-Everything (V2X) infrastructure. This study provides essential insights for policymakers and planners to better integrate Cooperative AVs into future transportation systems.</p>