CHOICE OF OFFSETS IN LINKING TRAFFIC SIGNALS

WHEN NEIGHBORING INTERSECTIONS IN A NETWORK OF ROADS ARE CONTROLLED BY TRAFFIC SIGNALS, DELAY TO TRAFFIC IN THE NETWORK CAN BE REDUCED BY LINKING THE SIGNALS SO THAT AS MANY AS POSSIBLE OF THE VEHICLES RELEASED BY ONE SIGNAL REACH THE NEXT DURING THE GREEN PERIOD. IF THE CYCLE TIME AT EACH INTERSECTION IS EITHER EQUAL TO A COMMON FIXED CYCLE TIME, OR ONE HALF, ONE THIRD, OR SOME OTHER SUBMULTIPLE OF IT, THEN LINKING THE SIGNALS BECOMES A MATTER OF DECIDING BY HOW MUCH THE BEGINNING OF EACH INDIVIDUAL SIGNAL CYCLE SHOULD BE OFFSET RELATIVE TO THE COMMON CYCLE. THE COMBINATION METHOD OF HILLIER AND WHITING ENABLES THIS CHOICE OF OFFSETS TO BE MADE FOR NETWORKS OF A PARTICULAR KIND IN SUCH A WAY THAT THE TOTAL DELAY TO TRAFFIC IN THE NETWORK IS MINIMIZED, SUBJECT TO A NUMBER OF ASSUMPTIONS. THE PURPOSE OF THIS PAPER IS TO SHOW HOW THE COMBINATION METHOD CAN BE ADAPTED SO AS TO APPLY TO A WIDER RANGE OF NETWORKS. ALTHOUGH THE METHOD ASSUMES THAT THE CYCLE TIMES OF THE SIGNALS ARE FIXED, IT IS ALSO RELEVANT TO THE LINKING OF VEHICLE-ACTUATED SIGNALS IN HEAVILY LOADED NETWORKS, BECAUSE SUCH SIGNALS WORK EFFECTIVELY AS FIXED-TIME SIGNALS WHEN FLOWS ARE HEAVY ENOUGH TO GIVE RISE TO MAXIMUM GREEN PERIODS ON ALL PHASES. TWO FORTRAN COMPUTER PROGRAMS HAVE BEEN WRITTEN TO (1) DETERMINE HOW THE NETWORK SHOULD BE BUILT UP, AND (2) CALCULATE THE DELAY-MINIMIZING OFFSETS. THE CAPABILITIES OF THESE PROGRAMS ARE DESCRIBED IN THIS PAPER. /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00410683
• Supplemental Notes:
  • Vol 10, pp 73-75
• Corporate Authors:

  N/A

  ,   United States 
• Authors:
  • ALLSOP, R E
• Publication Date: 0

Media Info

• Serial:
  • Traffic Engineering & Control
  • Volume: 8
  • Issue Number: 8
  • Publisher: Hemming Group, Limited
  • ISSN: 0041-0683
  • Serial URL: http://www.tecmagazine.com/

Subject/Index Terms

• TRT Terms: Digital computers; Intersections; Network links; Networks; Pretimed traffic signal controllers; Roads; Traffic actuated controllers; Traffic delays; Traffic flow; Traffic signal timing; Traffic signals
• Identifier Terms: FORTRAN (Computer program language)
• Uncontrolled Terms: Linkages
• Old TRIS Terms: Roadnet
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00227207
• Record Type: Publication
• Source Agency: Traffic Systems Reviews & Abstracts
• Files: TRIS
• Created Date: Aug 13 2004 6:56PM