Phase-based Rhythmic Control for Imbalanced Traffic Demands under a Connected and Automated Environment.

Traffic signal control, regarded as an effective and convenient control method of urban intersections, organizes traffic flows of different movements as phases and assigns right-of-ways in sequence to guarantee conflict free. With the development of connected and automated vehicle technologies, rhythmic control was proposed to control the intersection traffic in a more well-organized and efficient manner, by assigning right-of-ways for more movements concurrently. To improve the traffic control under various demands, this study proposes to combine rhythmic control and signal control to generate a new traffic control strategy, i.e., phase-based rhythmic control (PRC). Inheriting the phase-based control logic of signal control, rhythmic control is regarded as a special phase where the intersection traffic is organized in a different way. The P-RC takes full advantages of both control strategies, i.e., the ability of handling imbalanced demands of signal control and the merits of improving intersection mobility of rhythmic control. The performance metric of the admissible demand set is derived to highlight the superior capabilities of P-RC in handling various demand patterns. Given the demand information, we further propose an optimization framework for the design of a P-RC scheme. Extensive simulation tests are conducted to demonstrate the superiority of P-RC in various traffic scenarios, and some related features under the P-RC strategy are validated accordingly.