MULTIPLE RAMP CONTROL FOR A FREEWAY BOTTLENECK

MANY CURRENT APPROACHES TO FREEWAY CONTROL USE DETERMINISTIC MODELS OF TRAFFIC FLOW BASED ON THE CONTINUOUS FLOW-DENSITY CURVE. THIS PAPER PROPOSES A CONTROL STRATEGY BASED ON A TWO-STATE TRAFFIC FLOW PATTERN WITH THE PRIMARY CONTROL PARAMETER BEING THE PROBABILITY OF TRANSITION FROM UNCONGESTED FLOW TO CONGESTED FLOW. THE OBJECTIVE OF THE CONTROL IS TO MAXIMIZE THE REWARD ASSOCIATED WITH FREE FLOW. TRIAL SOLUTIONS INDICATE THAT FEASIBLE NUMERICAL VALUES FOR OPTIMUM CONTROL CAN BE EASILY OBTAINED, AND THESE WILL BE DEPENDENT ON THE LENGTH OF THE PEAK PERIOD. THE APPROACH SHOULD HAVE DIRECT APPLICABILITY TO EXISTING SURVEILLANCE AND CONTROL HARDWARE.