The River Basin Model is a man-machine simulation model used to delineate the interactions taking place, within a real or hypothetical area, between the local water system and the economic, social and governmental activities of that area; it is a model of an entire regional system, with water a subsystem realistically interacting with all the other major subsystems, such as housing and transportation. A gaming format is employed. The Governmental Sector (provides public services) and the model required by its bus and rail companies, and the computer printed output are described. The Governmental Sector establishes the amount of transit service, sets fares, and constructs rail lines and stations. Bus and rail companies provide the population in the simulated area with transportation service to be used for the trip to full-time work only; routes and modes of travel are assigned by the computer program. A social decision-maker assigns a dollar value for a time unit spent traveling to work by the people in his control.