Research on optimal control of two-way gaps at unsignalized intersections in a vehicle infrastructure cooperative environment

In order to improve the traffic efficiency of unsignalized intersections in the vehicle-road coordination environment, this paper proposes an integrated vehicle intelligent access control strategy based on the ‘two-way active gap adjustment method’. The approach integrates gap theory, defines active and passive adjustment mechanisms, and dynamically adjusts vehicle spacing and speed. By introducing a vehicle priority system, the priority requirements of emergency vehicles under different traffic flows are dynamically assigned. According to the various functions of the intersection area, the study divides the region into lane change zone, regulation zone, buffer zone, crossing zone, and recovery zone, establishes a conflict zone calculation model based on the physical dimensions of vehicles, and optimizes the elliptical trajectory of left-turning vehicles. The model predictive control algorithm adjusts the vehicle status in real-time to ensure that all kinds of emergency vehicles pass through the intersection safely and efficiently. The simulation results are verified by SUMO and Python platforms and compared with traditional signal light control and dynamic queuing priority control methods under different traffic flow conditions. The results show that the strategy proposed in this paper significantly improves traffic efficiency, reduces the average travelling time and delay, and at the same time reduces energy consumption and pollutant emission, enhances the adaptability of the system in high traffic flow and emergencies, and has obvious economic and environmental benefits.