Traffic congestion on urban arterials bring out many social problem, such as, increasing cost of transport and smoke. Construction of new roadways to relieve the traffic congestion on urban roads is unfeasible because of high cost and the lack of space. So researches are focused on controlling a traffic system efficiently and it is widely accepted as an appropriate method of solving the traffic problem.
Since it is impossible to use actual system, it is desirable that basement of research for a traffic system is simulation. But the absence of models which can represent the movement of vehicles in real traffic system hamper the development of over all traffic systems. And the absence of general control method which can cover various traffic systems in size and shape, must modify a control method according to changing of a traffic system.
To solve these problem in modeling and control method, a modular modeling of a traffic system using Petri nets and auto-making group control method are presented in this paper. The credibility modular models of intersection and road of Petri nets and performance of auto-making group control method is showed by simulation.