Railway Traffic Simulation by means of a Petri Net model

The paper explains the main results of an ongoing research concerning the development of a network model, including lines and stations, capable to simulate the traffic operations on the basis of the actions performed by the signalling components; this approach allows a high flexibility and capability to manage the traffic command and control operation. The model feasibility has been demonstrated and a global network model has been built up. It includes: i) a generalised station model to be applied to any lay-out and interlocking system; ii) a generalised line model to be applied for any signalling system. The represented network may be analysed with the simulation of different timetables without traffic density constraints. The main outputs of the model application are: i) the global rate of occupation for line and station components (track circuits, points, etc.); ii) the traffic development representation with the underlying of the critical situation (conflicts among trains). The model has been successfully tested on a network including a line section equipped with a codified currents automatic block signalling system and two stations.