The mixing of multi-mode connected and automated vehicles (CAVs) and multi-type human driving vehicles (HV) will become the normality in the future. This study aims to establish a fundamental diagram that can accurately describe the heterogeneous traffic flows with CAVs and HVs. Firstly, the traffic flow fundamental diagram of multi-type HVs is modeled based on the field data, and traffic flow parameters are calibrated; secondly, considering the difference of driving behaviors, the influence of CAVs mixed with HVs on the traffic flow characteristics is analyzed to establish the heterogeneous fundamental diagram; then, the credibility of the proposed fundamental diagram are verified by microscopic traffic simulation; finally, the sensitivity analysis of the penetration rate and driving behavior of CAVs are conducted. The results show the driving behavior of CAVs has a significant impact on traffic flow characteristics, while the increase of CAV penetration rate improves the roadway capacity.

Connected and Automated Environment;Heterogeneous Traffic Flows;Fundamental Diagram;Traffic Simulation