A new mobility field and gradient-based traffic signal control approach applicable to large-scale road networks

Previous traffic control models were usually developed on small or medium sized road networks. The traffic control models applicable to large-scale road networks have received growing interest. In this study, we develop a new mobility field and gradient-based traffic signal control approach applicable to large road networks. First, we introduce an emerging analytical technique, the mobility field approach, to generate the mobility field of urban travels and measure the gradients of the mobility field. Next, a gradient-based approach is proposed to identify the signalized intersections for implementing traffic control. Finally, a gradient-based traffic control model is developed to alleviate traffic congestion during mass events. A new solution algorithm, termed DBSCAN-FW-GA, is proposed to solve the developed traffic control model. The developed mobility field and gradient-based traffic signal control approach is validated using actual road network data and travel demand data. Results indicate that the proposed new traffic control approach can reduce by 17.97% the travel time compared with the widely used perimeter control approach.