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Track: Application Development Techniques
Anita Russo
University of Georgia
Chicopee Complex
1180 E Broad Street
Athens, GA 30602-5418
Telephone: 706-542-5323
Fax: 706-542-6535
E-mail: russo@itos.uga.edu
Doug Shepard
An Analysis of the Methodology for Creating Polygons from Line Vector Data
Defining Issue: The boundaries that define an area of interest do not necessarily follow the boundaries that define the areas for which data was collected. A method for defining an area of interest that could be used to extract data is with a custom polygon based on a drive distance from a start point on a road network. GIS Solution: Information Technology Outreach Services at the University of Georgia developed the Georgia 100 Geographic Information System that, among other things, provides the tools to create useful polygon study areas from line features representing a drive path. Methodology: The input to the process is a highway line coverage generated from TIGER data. NETWORK functions are used to find the endpoints of the drive path within the highway network. A sequence of BUFFER functions is used in the last stage of the process to determine the shape of the final polygon. Software: The application module is written in ARC Macro Language and employs ArcInfo CLIP, NETWORK, and BUFFER
functions to create a polygon coverage that represents the final study area. The purpose of this paper is to explore the methodology employed in creating drive distance study area polygons with special consideration given to 1. Alternative factors that may contribute to the shape of the final polygon 2. Limitations of the system
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