Multivehicle speed cooperative guidance and simulation at signalized intersections in mixed traffic involving connected and automated vehicles and human-driven vehicles

To address low traffic efficiency, high delay, and excessive energy consumption at signalized intersections in intelligent transportation systems (ITS) under the mixed traffic environment involving connected and automated vehicles (CAVs) and human-driven vehicles (HDVs), this paper proposes a time-window-based multivehicle speed cooperative guidance and optimization method. A zoned control design is proposed for the intersection approach, dividing the approach segment into a free-driving zone, a vehicle platooning zone, and a speed control zone. In the vehicle platooning zone, vehicle platooning constraints are established using the predecessor-leader-following (PLF) model to ensure the stability and safety of vehicle platoon operations. In the speed control zone, a multivehicle speed cooperative guidance strategy based on time window that accounts for platooning is proposed with the objective of enabling vehicles to pass through the intersection without stopping, and a trigonometric-function-based acceleration control model is introduced to smooth the optimal guidance speed and reduce speed fluctuations and frequent acceleration/deceleration. Simulations are conducted on a VISSIM-MATLAB platform under low, medium, and high traffic flows with different CAV penetration rates. The results show that the proposed method effectively reduces travel time, average delay, and fuel consumption, with greater benefits at higher CAV penetration rates. Under high-traffic conditions, the maximum reductions reach 20.54%, 46.96%, and 36.47%, respectively. These findings demonstrate that the proposed method can improve the operational efficiency and environmental performance of signalized intersections and provide methodological support for cooperative vehicle control and traffic management in ITS.