01139072

Component

This paper describes a meso-level demographic allocation technique employed for the 5 county travel demand modeling region in Austin, Texas. The goals of the system include incorporation of higher density Activity Center scenarios and use of travel time accessibility as an input. The tool is relatively simple to execute, using available goegraphic information system (GIS) data, and uses concepts relatively simple to understand. The result is a defensible, replicable, numerical tool that can store objective criteria which can be recalled for future analysis and review. The simplicity and low cost of the Meso-Level Demographic Allocation Tool makes it a highly valuable technique for use by smaller urban areas under 250K population. The CAMPO Demographic Allocation Tool is a TransCAD GIS-based computer program developed for the Capital Area Metropolitan Planning Organization (CAMPO) for iteratively allocating household and employment growth. The iterative process concludes when the user defined criteria on growth allocation are met. The tool allocates growth annually; nonetheless, CAMPO staff will aggregate growth in 10 year increments. Throughout the iterative process of allocation the tool considers the developable land, goal density, and a rating of attractiveness by traffic analysis zone. The total target growth and density goals are defined by CAMPO staff and will be recommended for adoption by the CAMPO Board. The presentation will describe the allocation procedure, starting from the estimation of developable land which is calculated based on the following factors: (1) Approved and planned development; (2) Natural/environmental constraints (flood plains, parks, preserves, steep slopes, water bodies, etc.; (4) Percentage of redevelopment, and (4) Vacant land. The tool allocates growth to small area grid cells which are then aggregated to TAZs. Designated Activity Centers receive additional attractiveness ratings and specialized density goals. The factors affecting the rating of attractiveness include: (1) Designation as an Activity Center (small, medium, or large); (2) User defined “Attractor Points” to reflect knowledge of locations with household and/or employment attractiveness, (3) Potential detractors to development (land fills, airport noise zones, etc.); and (4) Household and employment accessibility (transit and auto travel times from travel demand model). The Tool uses allocation “bins” to rank generalized areas of the region by attractiveness. Growth is distributed to each bin according to a user-defined function, in this case an exponential function is used. A simple user friendly interface allows input of attractiveness parameters, exponential function parameters, and control of scenarios as they are executed. Simplified mapping is also included in the Interface.

01138544

English

12p

2008

11th National Conference on Transportation Planning for Small and Medium-Sized Communities

CD-ROM

Tables

Activity centers; Demographics; Geographic information systems; Land use planning; Planning and design; Public transit; Sustainable development; Traffic analysis zones; Transportation planning; Travel demand; Travel time

Austin (Texas)

Data and Information Technology; Highways; Planning and Forecasting; Public Transportation; I72: Traffic and Transport Planning

TRIS, TRB

Aug 24 2009 1:51PM