Some 25 years ago, horizontal alignment design standards in both Australia and Canada closely resembled those recommended by the American Association of State Highway Officials (AASHO). Subsequent developments in curve design in both countries have resulted in a divergence in design practices. These developments, and the reasons for them, are reviewed. Developments in Canada have been in response to concerns with the very low levels of friction provided by icy roads and have involved reductions to design side friction factors for high speed alignments and changes to superelevation practice. Road surface friction is less of a problem in Australia and the major change has been the development of operating speed approaches to designing lower speed alignments with a view to providing satisfactory low cost alignments in difficult terrain. However, when allowance is made for the different design speed concepts, the actual differences in practice are not as great as would appear from a cursory comparison of the specified standards.

  • Record URL:
  • Availability:
  • Supplemental Notes:
    • The proceedings have been edited by the Texas Transportation Institute, Texas A&M University System, College Station, Texas. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • McLean, J R
    • MORRALL, J
  • Conference:
  • Publication Date: 1998-1


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 2:1-9
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00794659
  • Record Type: Publication
  • Report/Paper Numbers: E-C003
  • Files: TRIS, TRB, ATRI
  • Created Date: Jun 8 2000 12:00AM