The emergency vehicle signal priority control method for intersections considering pedestrian crossing safety

This paper focuses on the mixed intersections surrounding hospitals and proposes an emergency vehicle signal priority control method for mixed intersections that takes into account pedestrian safety. Special attention is given to the absolute priority characteristics of emergency vehicles, requiring the clearance of queued vehicles ahead of the intersection upon the arrival of an emergency vehicle to ensure absolute safety at the intersection, while considering the complexity of pedestrian traffic and traffic environment. The aim is to address the impact of urban traffic congestion on emergency rescue services during the process of urbanization. In response to the stochastic environment of mixed intersections, this paper proposes an algorithmic process for calculating the maximum queue length at the intersection for determining the clearing time. At the same time, pedestrian crossing signals are designed with safety in mind to ensure that the implementation of emergency vehicle priority strategies does not affect pedestrian safety, and the increased delay for pedestrians after priority control is calculated. On this basis, an optimization model that comprehensively considers the priority control of emergency vehicles, the efficiency and safety of intersection traffic is constructed, with priority duration quantifying the delay of vehicles at the intersection, and pedestrian delay is included to jointly represent the impact of emergency vehicle priority on intersection operations. An optimal signal control method solution process is designed. Finally, simulation experiments are conducted to verify the effectiveness of the proposed method. The results show that the method can reduce emergency vehicle delays by 98.2%, but the negative impact on the travel time of other vehicles and pedestrians at the intersection is only 4.7%. It can ensure the rapid passage of emergency vehicles while minimizing the negative impact on other traffic participants, showing good application prospects.