In 1997, the Transportation Association of Canada - the national custodian of Canada's Geometric Design Guide - commissioned a complete update of the existing guide, which had last been revised in 1986. A fundamental part of this update involved incorporating new thinking on the explicit evaluation of the road safety implications of geometric design decisions and a departure from the concept of "standards" as a basis for the provision of overall design guidance. This paper discusses the areas of major change introduced in the new guide and their implications for the professional practice of road design in Canada. The new concept of the Design Domain is presented and discussed. This concept was developed to address the difficulty of applying the concept of "standards", as they are thought of in other fields, to a process that necessarily requires the designer to exercise professional judgement and expertise in their application to roadway design. Its advantages and disadvantages are outlined and the technical aspects of its implementation are set out. The latter is accomplished through the provision of up to five levels of guidance for any given design criterion: numerical guidance on the upper and lower bounds of the domain; a commentary on its technical foundation; sets of heuristics for the application of the domain in particular circumstances; quantitative tools for the evaluation of safety performance; and worked examples of the application of the design domain to the design criterion under consideration. The authors outline the specific areas where efforts to incorporate quantitative tools and heuristics for the explicit evaluation of safety performance have been most successful and those where the information base is still insufficient. In the concluding section of the paper, the authors examine the implications of these changes for road agency administrators, design policies, and designers. They also comment upon the possible impact that the new guide will have on both road safety audit and value engineering processes.

  • 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:
    • Robinson, JBL
    • Smith, Gary A
  • Conference:
  • Publication Date: 2000-6


  • English

Media Info

  • Features: Figures; References;
  • Pagination: p. 49-56

Subject/Index Terms

Filing Info

  • Accession Number: 00794766
  • Record Type: Publication
  • Report/Paper Numbers: FGSV 002/67
  • Files: TRIS
  • Created Date: Jun 23 2000 12:00AM