A Novel Approach to Modular Control of Highway and Arterial Networks using Petri Nets Modeling

In this paper, integrated control of highways and intersections is investigated. A modular Petri-Net-based framework is implemented to model the traffic flow of highway and arterial traffic network systems. In this framework, arterial intersection traffic lights are modeled by Timed Petri Nets (TPN). The timing of traffic lights and variable speed limits on the highway is managed to be optimized using an intelligent algorithm. This algorithm provides a trade-off between the length of the queue of vehicles on the highway and the entrance ramp and the length of the queue at the intersection after each time cycle. The performance of the optimized traffic controller and the fixed control were compared. The simulation results verify that the use of optimization methods to manage the timing of traffic lights in intersections and speed limitation in highways can considerably improve traffic flow in special conditions such as rainy weather and accidents. Additionally, this method can considerably enhance traffic flow in normal hours, while in rush hours and midnight, such improvement is negligible.