ARCHISIM: MULTI-ACTOR PARALLEL ARCHITECTURE FOR TRAFFIC SIMULATION

Abstract

This paper presents a microscopic traffic simulation based on distributed architecture and on the concepts of multi-actors and multi-process. The information related to the network (topology, graph, and equipment) are considered available. In fact, they can be defined by using a graphic interface. The road objects occurring in this simulation are: the static objects, such as intersection and curve signs; the pseudo-static objects, such as flow sensors, traffic lights, and variable message signs; and the dynamic objects, such as vehicles and pedestrians. The dynamic objects also play a part as actors in the simulation. The last actor type is the intersection supervisor, which is in charge of a traffic lights group. The software architecture adopted is distributed, multi-actor, and multiprocess. The actors occurring in the simulation are: vehicles, pedestrians, and intersection supervisors. The processes simulated are: the road network manager, the vehicles, the pedestrians, and the intersection supervision. The network manager is the main process and has the global knowledge of the network. There is no direct communication link between the actors. The actors communicate only with the network manager process. At each communication, vehicle and pedestrian actors send to the network manager their location and their characteristics and ask it for their local vision; the intersection supervisor sends the color lights and asks for the contents of some specified flow sensors. The road network manager updates the graph. This parallel architecture can be used not only for a microscopic simulation but it can be connected to a piloted simulator; in this case it plays the part of traffic generator where the simulated vehicles react to the pilot actions.