| The Intelligent Vehicle Highway System (IVHS) project in Oakland County, Michigan, is a major federally-funded demonstration project of the real-time traffic adaptive signal system called SCATS (Sydney Coordinated Adaptive Traffic System). SCATS was installed in a part of the City of Troy (in Oakland County, Metropolitan Detroit, Michigan) in June 1992 and in the remainder of the city in November 1993. The role of the universities involved in this project is to evaluate the impact of this system. There are several criteria being analyzed in this evaluation including the number, type and severity of traffic accidents, the level of service (LOS), and the average speed on the major arterials.; A program, the Interactive Traffic Accident Geographic Information (ITAGI) system was designed to assist the analyst in evaluating the safety and delay (travel speed) effects of SCATS. The results of the accident analyses conducted in this project using the ITAGI system are described. From this database system, statistical analyses of any specific location or group of locations, both intersections and midblock areas in the city, can be conducted. The ITAGI system consists of a traffic accident geographic information system (GIS), quality control charts of accident rates developed by using the Monte Carlo simulation algorithm, and a safest path (through the network) algorithm.; Finally, after integrating the ITAGI system and a knowledge-based system, a multimedia left-turn control expert system was developed. The ITAGI system is a decision support tool for the multimedia left-turn control expert system. This expert system provides knowledge-based and user-friendly information to the user. It can help the operator in the traffic operations center analyze conditions and select left-turn control strategies in real time. In addition, it utilizes the computer-based multimedia techniques to store video images, audio voices, pictures, and graphics for CD-ROM computer use. The rules contained in the multimedia left-turn control expert system have been calibrated with a consistency check and a Turing test.; This paper, an integration of GIS and multimedia left-turn control expert systems, first describes the development of the ITAGI system, then highlights how the ITAGI system supports the actual safety and travel speed analysis before and after installation of SCATS. Second, this paper illustrates the development of the multimedia left-turn control expert system. It focuses on how the ITAGI system is used as a decision support tool to the multimedia left-turn control expert system, on how the expert system generates inductive rules by using the ID3 algorithm, and on how the expert system is calibrated with a consistency check and a Turing test. |
