Modeling and control of signalized intersections via first-order hybrid Petri nets

In this paper, an urban transportation network is considered to be a hybrid system, so including both continuous-time and discrete-event components. A formal model of a road junction with a two-phase signal control is developed using First-Order Hybrid Petri Nets, a special class of hybrid Petri nets. Based on such a model, a two-level regulation scheme is designed, which realizes traffic control at signalized intersections by minimizing the vehicle queue lengths. The proposed approach is modular, since the model of a general traffic network results from the composition of the basic modules describing the dynamics of the single intersections.