DESIGN OF A FREEWAY ENTRANCE RAMP MERGING CONTROL SYSTEM

AS FREEWAY TRAFFIC VOLUMES APPROACH SATURATION, MERGING VEHICLES ON THE ACCESS RAMPS EXPERIENCE FEWER ACCEPTABLE GAPS IN THE RIGHT LANE FLOW AND HENCE AN INCREASED DELAY TIME. THESE FACTORS COMBINE TO CREATE A NON-OPTIMAL MERGING PATTERN CAUSED BY DRIVERS WHO REJECT ACCEPTABLE GAPS OR ATTEMPT THE MERGING MANEUVER AT INOPPORTUNE MOMENTS. MANY REJECTED GAPS COULD BE ACCEPTED IF VEHICLES AT THE RAMP "NOSE" WERE IN MOTION, AND MANY MERGING ACCIDENTS COULD BE PREVENTED IF THEY WERE NOT. THE REPORT EXAMINES THE POTENTIAL IMPROVEMENT IN OPERATING PERFORMANCE OF AN ENTRANCE RAMP EQUIPPED WITH A GAP ACCEPTANCE CONTROLLER. SIMPLE METERING IS ALSO INCLUDED, AND RAMP VEHICLE DELAY CURVES FOR BOTH MODES OF OPERATION IN ADDITION TO UNCONTROLLED MERGING ARE PRESENTED. PARTICULAR ATTENTION IS FOCUSED UPON SYNCHRONIZATION OF THE MERGING VEHICLE AND ACCEPTABLE FREEWAY GAPS. A TECHNIQUE IS PRESENTED FOR APPROXIMATING THE GAP PROPAGATION PROBABILITY FUNCTIONS THAT ARE FUNDAMENTAL TO ANY DETERMINATION OF OPTIMAL RELEASE TIMES FROM THE RAMP OF VEHICLES IN THE GAP ACCEPTANCE CONTROL MODE. THE PROBLEM OF LOCATING THE FREEWAY SENSOR IS STRESSED. A QUANTITATIVE ILLUSTRATION NOTING THE APPLICATION OF THE SYNCHRONIZATION ALGORITHM IS PROVIDED. /UMTA/

• Supplemental Notes:
  • PROJ NO NY-URT-7
• Corporate Authors:

  Polytechnic Institute of Brooklyn

  333 Jay Street
  Brooklyn, NY  United States  11201
• Authors:
  • Klee, H J
• Publication Date: 1971-9

Subject/Index Terms

• TRT Terms: Control systems; Gap acceptance; Interchange ramps; Merging traffic; Traffic signal control systems
• Uncontrolled Terms: Synchronization
• Old TRIS Terms: Freeway entrances and exits; Freeway ramps
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226470
• Record Type: Publication
• Source Agency: Urban Mass Transportation Administration
• Files: TRIS, USDOT
• Created Date: Nov 7 1972 12:00AM