SYSTEM ANALYSIS METHODOLOGY IN URBAN TRAFFIC CONTROL SYSTEMS

DEVELOPMENT OF A SURVEILLANCE METHODOLOGY IS BEING STUDIED FOR USE IN A COMPUTERIZED TRAFFIC CONTROL SYSTEM. A SECONDARY OBJECTIVE WAS TO DEFINE FLOW/CONTROL INTERACTION PHENOMENA WHICH ARE IMPORTANT TO THE DEVELOPMENT OF IMPROVED TRAFFIC SIGNAL CONTROL TECHNIQUES, BUT WHICH HAVE RECEIVED LITTLE ATTENTION TO DATE. AN INVESTIGATION WAS CONDUCTED TO SELECT AN APPROPRIATE SET OF MEASURES OF EFFECTIVENESS (MOE'S) FOR A SIGNALIZED TRAFFIC SYSTEM. OVER FORTY MOE'S WERE FOUND IN THE LITERATURE AND THE LIST SYSTEMATICALLY REDUCED UNTIL THREE DISTINCT AND MEANINGFUL PARAMETERS REMAINED: TRAVEL TIME, ENERGY RATIO AND SERVICE RATE (TOTAL TRAVEL). THESE MOE'S CAN BE MEASURED USING DETECTORS IN THE STREET AND WITH THEM IT IS POSSIBLE TO EVALUATE THE EFFECTIVENESS OF VARIOUS CONTROL STRATEGIES. HAVING SPECIFIED THE SYSTEM EVALUATION MOE'S THE MEANS TO OBTAIN APPROPRIATE ESTIMATES OF THE MOE'S WERE EXAMINED. IN A COMPUTERIZED TRAFFIC CONTROL SYSTEM THE NECESSARY INFORMATION HAS TO BE PROVIDED IN A REAL TIME BY A SURVEILLANCE SYSTEM WHICH COLLECTS DATA USING TRAFFIC SENSORS AND TRANSMITS THE DATA TO AN ELECTRONIC COMPUTER FOR PROCESSING. THE ACCURACY AND INSTRUMENTATION REQUIREMENTS OF AN IMPROVED SURVEILLANCE METHODOLOGY WERE INVESTIGATED. THEN PLACEMENT AND FUNCTION OF DETECTORS WERE SPECIFIED, COMMUNICATION AND DATA-PROCESSING PROCEDURES WERE SELECTED AND, AS A RESULT, A COMPLETE SURVEILLANCE METHODOLOGY WAS DEVELOPED. THE DEVELOPED METHODOLOGY WAS VALIDATED AND REFINED USING SIMULATION TECHNIQUES. FINALLY, EVALUATION AND CLASSIFICATION OF EXISTING FLOW/CONTROL INTERACTION THEORIES AND MODELS WERE PERFORMED. AS A RESULT OF THE EVALUATION, CRITICAL AREAS FOR FUTURE STUDIES WERE IDENTIFIED. /BPR/