This paper aims to perform traffic simulations on traffic flow and congestion of the signalized network in urban area of Ube city and to try to improve the reproduction ability of current traffic situation by adjusting simulation conditions in heuristic manner. Time span of simulation is 24 hours including peak hours in the morning and in the evening when traffic congestion occurs. A microscopic simulation that has been developed based on discrete model is used. One of the feature of the simulation is that vehicles are assumed to take either of two mode of stopping and running to increase calculation efficiency. Another feature is that route selection is modeled.