Cooperative Optimization of Traffic Signal and Vehicle Trajectories under Mixed Traffic Flow

Connected and automated vehicles (CAVs) and human-driven vehicles (HDVs) are expected to form the mixed traffic flow in recent decades. This paper studies the control problem of the mixed traffic flow at a signalized intersection. A two-level cooperative control method is proposed to optimize both intersection signal timing and trajectories of CAVs. At the upper level, to minimize total travel delay, dynamic programming is used to find the optimal phase scheme at the beginning of each signal cycle and assign arrival time to vehicles. At the lower level, CAVs trajectories are generated from downstream to upstream of the control zone in sequence based on optimal control with the objective of driving comfortably and economically. Numerical experiments are conducted in the traffic simulation platform SUMO, showing that the proposed method can reduce travel time and fuel consumption effectively compared with the traditional actuated control.