THE EFFICIENCY OF ISOLATED TRAFFIC SIGNAL CONTROL CAN BE SUBSTANTIALLY IMPROVED BY USING MORE ADVANCED CONTROL STRATEGIES IN COMBINATION WITH BETTER METHODS FOR TRAFFIC DETECTION. THE PURPOSE OF THIS STUDY WAS TO DEVELOP AND TEST SUCH METHODS FOR PRACTICAL USE. A CONTROL STRATEGY NAMED TOL (TRAFFIC OPTIMISATION LOGIC) BASED UPON THE CRITERION OF MINIMISATION OF TRAFFIC OPERATING COSTS AND DISTURBANCE OF THE ENVIRONMENT AT A GIVEN TRAFFIC DEMAND WAS DEVELOPED. THE METHOD CALCULATES AT REGULAR INTERVALS IF THE PREVAILING PHASE SHOULD BE EXTENDED OR NOT BASED ON SHORT-TERM PREDICTIONS OF THE RESULTING BENEFIT AND DISBENEFIT TO THE DIFFERENT CATEGORIES OF TRAFFIC IN THE INTERSECTION. TOL WAS TESTED AND COMPARED WITH CONVENTIONAL FIXED-TIME AND VEHICLE-ACTUATED (VA) CONTROL, WITH OR WITHOUT BUS PRIORITY, BY MEANS OF SIMULATION AND FIELD EXPERIMENTS. BOTH SIMULATION AND FIELD EXPERIMENT RESULTS SHOWED THAT TOL COULD DECREASE AVERAGE DELAY BY 25 PER CENT FOR VEHICLES AND 40 PER CENT FOR BUSES AS COMPARED WITH VA. COST-BENEFIT ANALYSIS SHOWED THAT THE TOL SYSTEM WAS COST-EFFECTIVE EVEN IF ONLY THE BENEFITS OF REDUCED GASOLINE CONSUMPTION WERE CONSIDERED. IN SOME CASES TOL WAS COST-EFFECTIVE EVEN IF ONLY THE GASOLINE REDUCTION FOR THE BUSES WAS CONSIDERED. (A). FOR THE COVERING ABSTRACT OF THE CONFERENCE PROCEEDINGS SEE IRRD ABSTRACT NO. 226354.
Abstract