A COMPARISON OF OBSERVED AND ESTIMATED QUEUE LENGTHS AT OVERSATURATED TRAFFIC SIGNALS

Queue lengths estimated by two recently-developed formulae are compared with observed values on oversaturated approaches to traffic signals. The data collection procedure is described in detail. To ensure compatibility between observed and estimated queue lengths it is necessary to modify observed arrival rates and queue lengths, and this process is also described in some detail. With an assumption of constant departure rate for fully saturated cycles, both formulae produce poor estimates for two of the three sets of data available. The implications of this result for signal-setting and time-dependent assignment procedures are discussed, and possible methods of improving estimation are described. When the departure rate is allowed to vary and the peak periods are divided into 12-minute intervals, both formulae give adequate representations of queue length and delay. /Author/TRRL/

  • Availability:
  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Branston, D
  • Publication Date: 1978-7

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Filing Info

  • Accession Number: 00183371
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Dec 29 1978 12:00AM