An Intelligent Traffic Light Scheduling Algorithm by using fuzzy logic and gravitational search algorithm and considering emergency vehicles

Document Type : Research Paper


1 Departament of computer engineering, Qom Branch, Islamic Azad University, Qom, Iran.

2 Departament of computer engineering, South Tehran, Islamic Azad University, Tehran, Iran

3 Departament of computer engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.



Traffic lights play an important role in urban transportations, but they also cause delays in streets leading to junctions. Scheduling of traffic light, therefore, puts a considerable effect on urban traffics and routing delays. The proposed routing aims to route the vehicle agent so that the driver arrives at its destination by the fastest path. In this paper, a new intelligent algorithm is proposed for scheduling traffic lights to decrease traffic density and less delay in routing. This algorithm considers traffic flow density and the presence of emergency vehicle agents. The algorithm evaluates the status of the traffic flow by fuzzy logic. The evaluation is done by considering traffic flow speed and density. The output of fuzzy logic is used by Gradational Search Algorithm (GSA). GSA considers the status of the flow, the priority of the traffic flow, and the distance of the emergency vehicle to the traffic light. The simulation results prove that the proposed algorithm has better performance.