The Gauteng Department of Transport and Public Works, South Africa, is being confronted by increasing demands for access to freeways. In consequence, there is a need to determine minimum spacings of interchanges that would be able to address these demands without compromising the operation of the freeway system. A survey of international practice was conducted and the operational effectiveness of various sections of the freeway system analysed. Interchange spacings compatible with signage requirements as specified in the South African Road Traffic Signs Manual Interchange were determined and recommended as desirable minima. Spacings are given in terms of Yellow Line Break Point distances. For urban areas, these distances are 1300 m, 2100 m and 1400 m for access to access, access to systems and systems to access configurations, respectively. For rural areas, the corresponding distances are 2200 m, 3300 m and 1900 m. The weaving operation was examined and Yellow Line Break Point distances of 660 m, 450 m and 1100 m were recommended as absolute minima in respect of the merge-diverge, Type A and Type B weave, respectively. It is to be noted by American and European readers that this paper is presented from the perspective of driving on the left. In the text, therefore, "left" is to be read in the context of "right" and vice versa in American and European terms when these words have a spatial connotation.

  • Supplemental Notes:
    • The publisher's German name is Forschungsgesellschaft fur Strassen- und Verkehrswesen (FGSV).
  • Corporate Authors:

    Road and Transportation Research Association

    Postbox 50 13 62
    D-50973 Cologne,   Germany 
  • Authors:
    • Ingham, D J
    • Burnett, S L
  • Conference:
  • Publication Date: 2000-6


  • English

Media Info

  • Features: References; Tables;
  • Pagination: p. 534-546

Subject/Index Terms

Filing Info

  • Accession Number: 00794811
  • Record Type: Publication
  • Report/Paper Numbers: FGSV 002/67
  • Files: TRIS
  • Created Date: Jun 28 2000 12:00AM