DELAYS AT ROUNDABOUTS CAUSED BY GEOMETRIC DESIGN FACTORS

The delay to vehicles negotiating a roundabout is currently assumed within the Department of Transport's Cost Benefit Analysis Programme (COBA) to be related to approcah road speed and island diameter. This paper describes the survey work, analysis and results of a study designed to reassess these geometric delay values currently in use. Preliminary assessments were performed at over 200 possible study sites and detailed delay information was collected at the 12 most suitable locations. A multi-channel event recorder was used for the major part of the data collection. The delay values were found to be of the same order of magnitude as those used in COBA although a different method of calculation has been suggested. In addition, the effects of vehicle type and turning movement on delay have been estimated.(a) /TRRL/

  • Availability:
  • Corporate Authors:

    Whitehall Technical Press Limited

    Wrotham Place
    Wrotham, Sevenoaks, Kent ME14 1PE,   England 
  • Authors:
    • McDonald, M
    • Noon, C
  • Publication Date: 1978-12

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 9
  • Serial:
    • Highway Engineer
    • Volume: 25
    • Issue Number: 12
    • Publisher: Whitehall Press Limited
    • ISSN: 0306-6452

Subject/Index Terms

Filing Info

  • Accession Number: 00193993
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jun 13 1979 12:00AM