STUDY ON THE MECHANISMS OF CAV TRAFFIC FLOW IMPACT IN URBAN MULTI-REGION ENVIRONMENTS

This paper studies the macroscopic dynamic evolution of mixed traffic flow with an emphasis on the effects of interconnection between multiple urban zones. A macroscopic fundamental diagram (MFD) model is proposed, which integrates the characteristics of both connected and autonomous vehicles (CAVs) with human-driven vehicles (HDVs) into the traditional triangular MFD. The model accounts for differences in reaction times between CAVs and HDVs, as well as the topology of the urban road network and traffic signal control schemes. Numerical simulations were conducted on a 30 km real-world street network in Jinan, China, to assess the impact of various CAV penetration levels (0%, 20%, 40%) on traffic flow dynamics across different urban neighborhoods. The results demonstrate that at low levels of CAV penetration (0%-20%), mixed traffic flow shows reduced capacity compared to pure HDV traffic due to adaptation difficulties between CAVs and HDVs.