Abstract
Demand estimation for a toll road is of great importance not only in its planning stage of the road system but also in the operating stage. This paper deals with a System Dynamic model of a decision making process of the users of the urban expressway and with the results of simulation runs for the Hanshin Expressway users with Dynamo II. At first the System Dynamics is explained and then demonstrates the validity of the System Dynamic model by comparing the simulated results with the real data.