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Newer integrated land use–transport models require as a base-year input a representation of existing built form (building stock by type, age, density, and other variables). Available data on floor space inventory have been found to be both incomplete and inconsistent with employment and population data in three land use–transport modeling exercises in the United States: in Sacramento, California; in the state of Oregon; and in Oahu, Hawaii. This paper reports on three methods used to synthesize a built-form input at a detailed microlevel for these three models. Each method uses existing land cover data and reconciles them with population data, employment data, and data on the consumption of floor space by activity. All three approaches assign floor space quantities by type to a detailed microlevel (grid cell or parcel) inventory of land. The approaches differ in their algorithmic approach, motivations, and data requirements.

Oregon has a long history of developing and using integrated economic, land use–transport models. Development of the Oregon Statewide Integrated Model (SWIM) was commissioned by the Oregon Department of Transportation as part of its Transportation and Land Use Model Improvement Program within the larger Oregon Modeling Improvement Program. The first version model, now named SWIM1, has been used in numerous applications since the late 1990s. A more extensive second version, SWIM2, is now available. It uses the PECAS economic input–output activity allocation framework, an aggregate model of spatial development and microsimulation models of freight and person transport. This paper describes the work considered in the later stages of development of the SWIM2 model, including results of sensitivity testing and reports on concurrent actions to transfer the model to agency operation. The sensitivity tests considered three alternative scenarios covering the evolution of the statewide spatial economic and transport systems over a 19-year period. Each scenario was compared to a reference case. In one scenario, highway capacity was increased substantially along an Interstate corridor radiating out from the Portland metropolitan area for more than 100 mi. In the other two scenarios, the costs for vehicle travel were increased four- and 10-fold over 1998 costs. The model system was found to respond consistent with a priori expectations. Population and employment shift to areas of comparatively better accessibilities, urban densities change, trip lengths and modes change, and floor space development and prices respond to these changes in patterns that evolve across the state over time.

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