A GEOGRAPHIC INFORMATION SYSTEM APPLICATION TO REGIONAL SUBAREA TRANSPORTATION MODELING

A super-regional area is an area encompassing several counties, 40 to 100 miles across which often spans several states. It may be thought of as the 'influence' area of the major city, larger than the MPO boundary, more like the 'television market' or 'maximum commuting market'. The super-regional model allows for the subarea modeling or subarea focusing within its framework. This ability to "downscale" from a regional database enables one to review proposed projects for a subarea and socioeconomic projections in a regional context. While super-regional and subarea modeling and alternative analysis can be done without the aid of a GIS system, the combined effect of the graphical abilities of GIS, super-regional and the subarea models prove to be a powerful tool in analysis of transportation alternatives. It is shown that the GIS-T procedure permits identification of the regional impacts of the roads proposals. This paper demonstrates that GIS can be a essential element in the analysis of future traffic volumes and associated data in "fuzzy-framed" subarea modeling from a super-regional model.