URBAN DEVELOPMENT MODELS FOR THE SAN FRANCISCO REGION: FROM PLUM TO POLIS

Most of the operational urban development models were designed 15 years ago and do not reflect the planning concerns of the 1980s. PLUM (Projective Land Use Model), the land use system developed for the Bay Area in 1970, suffers from conceptual and operational limitations that hinder its use. A new model, which is structurally and behaviorally different from the traditional Lowry models, was designed at the Association of Bay Area Governments. The new model, referred to as POLIS (Projective Optimization Land Use Information System), is based on microeconomic behavioral principles; it is formulated as a mathematical programming problem and considers job location, housing selection, and trip making in an integrated fashion.