Speed Harmonization for Partially Connected and Automated Traffic

Abstract

This paper proposed a speed harmonization controller for partially connected and automated traffic. It regulates the flow rate of the entire traffic by adjusting only the target cruising speed of Connected and Automated Vehicles (CAVs). The proposed controller bears the following features: i) applicable to partially connected and automated traffic consisting of CAVs and HVs; ii) ensuring the stability of the traffic system under control; iii) precise demand management on a multi-lane road with the help of a small portion of vehicles; iv) providing the foundation for future CAV-based traffic management strategies. To evaluate the proposed controller, a microscopic simulation evaluation was conducted. Sensitivity analysis was performed for CAV Penetration Rate (PR), demand level (v/c ratio) and target demand drop. Results confirm that the control accuracy of the proposed controller is up to 95% and generally over 80% across all CAV PRs, demand levels and target demand drops (within 20%). A case study is presented to demonstrate the benefit of applying the proposed controller on a bottleneck. By preventing the onset of a breakdown and, along with it, a capacity drop, the proposed controller is able to increase the flow rate by 6%, reduce the number of stops by up to 90% and delay by approximately 5%.

Keywords: Active traffic management, Partially connected and automated traffic, Speed harmonization, System dynamics