TRAFFIC SIGNAL CONTROL USING CABLELESS LINKING - THE A4 EXPERIMENT

THIS PAPER GIVES AN ACCOUNT OF AN EXPERIMENT CARRIED OUT ON THE A4 TO FIND OUT WHETHER THE LINKING OF TRAFFIC SIGNALS ALONG A RADIAL ROUTE PROVIDED WORTHWHILE BENEFITS. THE AUTHORS POINT OUT THAT BECAUSE CONVENTIONAL LINKING COSTS INCREASE WITH DISTANCE, AND, AT THE SAME TIME, BENEFITS DECREASE BECAUSE OF TRAFFIC DISPERSION, 500M IS THE NORMAL ECONOMIC LIMIT. LONGER DISTANCES WOULD REQUIRE LESS DISPERSION THAN IN CITY CENTRES AND A REDUCTION IN COST OF LINKAGE. OBSERVATION AT THE SITE OF THE EXPERIMENT SHOWED THAT PLATOON DISPERSION WAS, IN FACT, LESS AND JUSTIFIED LINKAGE UP TO 1KM PROVIDED COSTS COULD BE KEPT LOW. A SYSTEM OF CONTROL BASED ON 24 HOUR CLOCKS SYNCHRONISED TO THE ELECTRICAL SUPPLY FREQUENCY WAS USED FOR THE EXPERIMENT, ITS COST BEING $6,000 AS COMPARED WITH AN ESTIMATED $35,000 FOR CONVENTIONAL EQUIPMENT. DETAILS ARE GIVEN OF THE SYSTEM OPERATION (BASED ON THE TRRL TRANSYT/5 COMPUTER PROGRAMME). THE METHOD OF ASSESSMENT AND THE RESULTS. THE RESULTS ARE DISCUSSED IN RELATION TO JOURNEY TIME, VARIATION IN JOURNEY TIME AND NUMBER AND COST OF VEHICLE STOPS. IT WAS CONCLUDED THAT LINKED TRAFFIC SIGNALS ON SUCH SITES WERE WORTHWHILE, BOTH IN TERMS OF REDUCED JOURNEY TIME AND THE COST OF VEHICLE STOPS.

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  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • GREEN, F B
    • ROBERTSON, D I
  • Publication Date: 1974-4-5

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Filing Info

  • Accession Number: 00080860
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Mar 26 1975 12:00AM