TRAFFIC STUDIES AT T-JUNCTIONS. 4. THE EFFECT OF SPEED ON GAP ACCEPTANCE AND CONFLICT RATE

Gap acceptance for a simple crossing manoeuvre at a t-junction is measured and analysed in terms of the speed of approaching vehicles. The median accepted gap D in feet is related to the approach speed V in ft/sec by D = 115+1.9V (with D in metres, V in m/sec., D = 35+1.9V). The median accepted gap consists of a constant time of 1.9 sec plus a constant distance of 115 ft (35 M). This result, with a similar result for merging turns, is tested in a conflict simulation model. It is found that the fast drivers on the major road are more at risk than the slow drivers, and that the overall level of risk increases with increasing dispersion of speed. The bias of the observed gap acceptance functions is briefly discussed, and it is noted that gap acceptance may not by itself be a sufficient indicator of risk.(a) /TRRL/

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  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Cooper, D F
    • Storr, P A
    • Wennell, J
  • Publication Date: 1977-3

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00159723
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analytic
  • Files: ITRD, TRIS
  • Created Date: Mar 29 1978 12:00AM