EFFECTS OF ERRORS IN LOST TIMES ON THE DELAY TO TRAFFIC AT AN ISOLATED ROAD JUNCTION CONTROLLED BY FIXED-TIME SIGNALS

THE DATA REQUIRED FOR THE CALCULATION OF DELAY-MINIMIZING SIGNAL SETTINGS AT A SINGLE ROAD JUNCTION, SUBJECT TO SPECIFIED MAXIMUM CYCLE TIME AND MINIMUM GREEN TIMES, ARE THE AVERAGE ARRIVAL RATE AND SATURATION FLOW OF TRAFFIC ON EACH APPROACH TO THE JUNCTION, TOGETHER WITH THE TOTAL LOST TIME PER SIGNAL CYCLE AND THE AMOUNT OF THIS LOST TIME THAT IS EFFECTIVELY GREEN FOR EACH APPROACH. THIS PAPER SHOWS HOW THE RESULTING SIGNAL SETTINGS ARE AFFECTED BY SMALL ERRORS IN ALL THESE DATA. IT GOES ON TO ESTIMATE THE DIFFERENCE BETWEEN THE DELAY PER UNIT TIME AT THE JUNCTION WITH SIGNAL SETTINGS CALCULATED FROM ERRONEOUS DATA AND THE DELAY PER UNIT TIME THAT WOULD OCCUR IF THE SIGNAL SETTINGS WERE CALCULATED FROM TRUE DATA, SUBJECT TO THE SAME MAXIMUM CYCLE TIME AND MINIMUM GREEN TIMES. SEVERAL NUMERICAL EXAMPLES FOR A SIMPLE CROSSROADS ARE GIVEN AND THE RESULTS ARE DISCUSSED. IT IS SHOWN THAT THE EFFECTS ON DELAY OF SMALL ERRORS IN THE LOST TIMES CAN BE LARGE. THE METHOD DESCRIBED SHOULD HELP TRAFFIC ENGINEERS TO IDENTIFY SITUATIONS WHICH CALL FOR PARTICULARLY CAREFUL MEASUREMENTS OF CONDITIONS AT THE JUNCTION, ESPECIALLY THE LOST TIMES, AND TO ESTIMATE THE RANGE OF CONDITIONS FOR WHICH PARTICULAR SIGNAL SETTINGS ARE LIKELY TO BE SUITABLE. (A)

  • Authors:
    • ALLSOP, R E
  • Publication Date: 1973-6

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 145-62
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00226892
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: Jul 16 1974 12:00AM