This paper evaluates the use of geographical information systems (GIS) in network construction, as a step towards the full integration of four-step regional traffic simulation models into a GIS environment. GIS already has substantial potential to help the construction of link and node networks for such models, through the use of the US Bureau of the Census TIGER files and other electronic files with complete street coverage. However, the details of files like TIGER are not yet compatible with the models. The paper presents a method of reducing such details to a level reasonable for a four-step model network, by stripping the file of excess links and nodes. Three examples were studied, where: (1) a network was studied, where: (1) a network was identified, independent of the GIS and TIGER file; (2) census geography and TIGER street files were used directly and interactively to develop zone and network structures; and (3) the GIS was used to display a full coverage background map, from which additional nodes and links could be added to an existing network model displayed in the foreground. The proposed reduction of TIGER files to a usable level worked for examples (2) and (3) but not for (1).
Abstract