SIG-GIS: A GIS based traffic signal coordination and information management system

This research investigates the use of geographic information system (GIS) technology as a tool in traffic signal information management and signalized intersection coordination. TRANSYT-7F is the most widely used and respected computer model for optimizing the coordination of traffic signals. Unfortunately, creating an optimum TRANSYT-7F model is very costly. The hypothesis of this research was that using a specialized GIS in conjunction with TRANSYT-7F could enhance the process of coordinating a traffic signal sub-system. This hypothesis has been realized through the development of a fully functional GIS based signal coordination and information system. This system is an improvement over existing methods of creating optimum TRANSYT-7F models because it enhances speed by providing automatic generation of required data such as street distances and upstream traffic volumes. The process of analyzing different network optimization scenarios is simplified with this system because the user need only to select intersections to be coordinated from the GIS graphic display rather than cutting and pasting from existing input files. The system also has a facility that can generate a link-node diagram which facilitates the calibration process and fine tuning of implemented signal settings. Alternatively, the system can serve as a multi-purpose signal information system. By being multi-purpose, the system could play a vital role in decision support. It can provide improved access to signal data because queries can be made simply by selecting an intersection from the map display. Furthermore, the system allows for swift identification of intersections that experience excessive delays, unacceptable levels of service, or a high number of maintenance activities in a short period of time.