DEVELOPING SMALL-AREA NETWORK PLANNING-MODELS USING DESK-TOP GIS

Personal computer implementations of urban transportation planning (UT P) packages have resulted in a proliferation of modeling efforts. Howe ver, staff experience and availability, particularly at small planning agencies, has not kept up with this proliferation, and many agencies that could benefit from a model go without. As many UTP models are com plex and difficult to use, improved graphical interfaces and visualiza tion tools are needed to create more intuitive modeling environments t hat take advantage of limited or dwindling staff resources. Furthermor e, new opportunities exist as more and more graphic-based data are bec oming available via the internet and CD-ROM from sources such as the C ensus Department, the Bureau of Transportation Statistics, and aerial/ ortho-photography projects. In this paper, tools are presented and ste ps are recommended for developing UTP models using desktop geographic information systems. Using the city of Ames, Iowa, as a case study, th ese procedures and tools are shown to facilitate integration of spatia lly referenced data for efficient model development. Several GIS-based techniques are also presented for enhanced visualization of model adj ustments in calibration and validation.