UrbanSim is an open-source modelling system which operates at very fine geographical scale and relies heavily on discrete choice models. The fine level of detail requires a great deal of data so that data collection and preparation can take up to two years. A few successful UrbanSim applications have been reported in the literature, but these have been produced primarily by the model developers. Given the potentially demanding requirementsof using UrbanSim, planning organizations considering developing integrated models should like to know just what is involved in developing an UrbanSim model, and how difficult it is to do. This paper provides a users' side view of the use of UrbanSim. The research involved the development of UrbanSim models for two different cities. In a 'data-poor' case, for Brussels in Belgium, aggregate land-use and demographic data were disaggregated and used in UrbanSim. This case is compared with a 'data-rich' case (of Lausanne in Switzerland) where plentiful disaggregate data were available. The analyses provide a number of important conclusions with respect to the use and operation of UrbanSim. First, it reveals that the amount of work required to develop an UrbanSim model, while not being automatic, is comparable to what could be expected for the development of a four-step model. Second, it reveals that the use of aggregate and synthetic data (on households, jobs and buildings) can provide respectable results in an UrbanSim model. At the same time, some data turn out to be very critical in the operation of UrbanSim. In particular, sufficient historical development data (onwhich the real-estate development models are calibrated) is very important in the successful operation of UrbanSim. Moreover, the availability of accurate zoning data proves indispensable in assuring the reasonable placement of jobs, households and real-estate development. For the covering abstract see ITRD E145999
Abstract