The optimization of urban systems objective functions



Journal Title

Journal ISSN

Volume Title



A generalized computer program has been developed which enables the representation of the interaction of social segments of an urban structure. This program is presented in detail such that it can be adapted to any particular urban system of interest. However, the adaptation presented herein is to Harris County, Texas. The calibration has been, accomplished utilizing data extracted from magnetic tapes produced by the Census Bureau, U.S. Department of Commerce (1970 census). This model is the Housing Allocation and Location Optimization (HALO) model. The model functions in a dynamic manner over a selected global analysis period. The assumption is made that the global analysis period may be represented by a series of discretized analysis periods. During each of these periods, a certain portion of the households is assumed to enter the market seeking to relocate. The model must satisfy a set of quantitative constraints pertinent to the particular geographical region of interest to achieve equilibrium. Several features of this model are unique and provide significant improvement over previous models: The tremendous problem of evaluating preference factors by regression techniques is completely eliminated by the inclusion of generalized weighting factors. A multi-dimensional array is incorporated to control the supply and demand of the housing market. This feature reflects the various degrees of dependency of construction upon the economic situation experienced by different types of housing units. The capability of selecting an optimum location within the geographical region is provided. A generalized user specified objective function is optimized in the global analysis period. This facilitates the selection of optimal sites for the location of various installations. After the model is calibrated to any area of interest, it can be used to evaluate various policies. Two different policies are implemented in this page. A new school district is created from an existing school district and the affect on the housing distribution is presented. The housing pattern change caused by the completion of a new freeway is also presented. In each case, the impact caused by the policy implementation is evident.