Integration of land use plans and transportation plans has long been a goal of many regional long range planning efforts. However, it has proven to be a formidable process to link roadway and transit plans with land use plans. The Capital Area Metropolitan Planning Organization (CAMPO) has recently implemented a GIS-based Demographic Allocation Model that forecasts households and employment at the parcel level for a 6-county region. In this process, CAMPO has established a direct linkage to local land use plans at the parcel level that makes the process of land use/transportation explicit for the travel demand modeling process and as input to the regional Metropolitan Transportation Plan (MTP). This paper describes the technical process used in the demographic model and how local land use plans were directly used as inputs to the process. The result is the most detailed estimate and forecast of population, households, and employment ever performed in the region, with over 600,000 parcels available in the GIS. Descriptions in the paper include development of inputs to the model from local land use plans, conceptual densities, holding capacities, and mixed use representation. The paper describes challenges faced in development of the parcel level estimates, forecasts, and communicating with local land use planners to gather input. The paper also describes the methodology that the demographic model employs, and reveals advantages and disadvantages of developing a regional parcel level GIS for demographic forecasting.