STUDY OF TRAFFIC RESPONSIVE RAMP CLOSURE CONTROL

RAMP METERING IS EFFECTIVE FOR IMPROVING FREEWAY OPERATIONS BY REDUCING THE TRAFFIC INPUT TO THE FREEWAY. FOR RAMP METERING CONTROL, THERE IS A MINIMUM RATE FOR VEHICLES ENTERING THE FREEWAY. IF THE CONTROL RATE IS SET BELOW THIS LEVEL, MOTORISTS BEGIN TO VIOLATE THE METERING SIGNALS, AND THE RAMP FLOW RATE IS INCREASED. TO REDUCE TRAFFIC INPUT BELOW THE MINIMUM METERING RATES, POSITIVE RAMP CLOSURES ARE STUDIED IN THIS REPORT. THE RESULTS WERE THAT FREEWAY OPERATION IMPROVED, AND RAMP TRAFFIC SUFFERED ONLY MINIMUM ADDED DELAY. A MORE AUTOMATED SYSTEM OF RAMP CLOSURE SHOULD BE CONSIDERED FOR BETTER AND MORE RESPONSIVE OPERATION TO TRAFFIC CONDITIONS IN BOTTLENECK AREAS.