Virtual-Grid Based Traffic Control Strategy With Multiple Intersections Collaboration

This paper proposes a dynamic cooperative traffic control framework for multiple intersections based on virtual grids to optimize the throughput and ensure fairness among all traffic flows. The traffic flows are divided by virtual grids; we call it virtual grid-based cooperative control of multiple-intersections (VGCC). The road segment between two intersections has been divided into two parts, which are defined as the reference region and the decision region. When the vehicle arrives at or goes away from any one part, it registers or deregisters itself to the road side unit. The traffic controller at intersection, called intersection control unit, collects the traffic information from all road segments and receives traffic messages from adjacent intersections. The proposed signal-scheduling algorithm considers not only the flows at the local intersection with higher passing rates but also the flows at downstream signalized intersections with higher passing rates. To ensure fairness, the algorithm gives chances to those phases who has a lower passing rate by using the ageing-counter matrix. According to the real-time traffic information, this paper makes signal timing for each phase of a signal cycle one by one. Moreover, a cooperative collision avoidance predictive control algorithm is proposed, which can assist vehicles to pass the next intersection without stopping, by predicting the time conflict. The results indicate that the VGCC algorithm significantly decreases the average number of vehicles on a road segment by 30.77%, reduces the average queuing length by 28.89%, decreases the average time spent on passing intersection by 26.93%, and reduces the average waiting time by 35.21% than the intersection of common road networks algorithm.