Hybrid Signal Control for Isolated Intersections under a Connected and Automated Environment

The development of connected and automated vehicle (CAV) technologies provides great potential for improving traffic control at urban intersections. This paper proposes an innovative intersection control scheme in a fully CAV environment. By combining traffic signal control (TSC) and rhythmic control (RC), a hybrid signal control (HSC) scheme is developed to take the advantages of the two control methods, that is, the capability of reducing intersection delay of RC and the flexibility of handling imbalanced demands of TSC. Steady-state properties of HSC are theoretically derived, which demonstrate the admissible demand set of HSC dominates those of RC and TSC. The optimal design of phase choice, phase timing, and cycle length for HSC is formulated as linear optimization problems. Numerical experiments are conducted to test the performance of HSC, and the results show that HSC is capable of effectively accommodating imbalanced traffic demand.