DEVELOPMENT OF AN INTERACTIVE TRAFFIC ACCIDENT GEOGRAPHIC INFORMATION SYSTEM (GIS) FOR OAKLAND COUNTY, MICHIGAN

The Intelligent Transportation System (ITS) project in the City of Troy, Michigan, is a federal demonstration project of a real time traffic adaptive signal system, Sidney Coordinated Adaptive Traffic System (SCATS). SCATS was initiated in a part of the City of Troy, Michigan in June 1992 and the remainder of the city in November 1993. The criteria being evaluated in this project include the number, type, and severity of traffic accidents; intersection delay; and average speed on the major arterials. The Interactive Traffic Accident Geographic Information (ITAGI) system was designed to assist the analyst evaluate the effects of SCATS. In this paper, the development and capabilities of the system in conducting accident analyses are described. From this database system, statistical analyses of any location or group of locations, both intersections and midblock areas in the City of Troy, can be conducted. The ITAGI system consists of computer programs designed to display traffic accident characteristics (such as type of accident) at any location; to identify statistical outliers using accident rates; and to display the safest path through the network. Finally, after integrating the ITAGI system and a knowledge based system, a multimedia left-turn control expert system was developed. This expert system uses data from the ITAGI system to select left-turn control strategies. This expert system provides a tool to supplement the experience of individual operators and reduce the potential for incomplete or incorrect responses.