A COMPARISON AND EVALUATION OF THE GEOMETRIC DESIGN PRACTICES WITH PASSING LANES, WIDE-PAVED SHOULDERS AND EXTRA-WIDE TWO-LANE HIGHWAYS IN CANADA AND GERMANY

Passing lanes (also known as three-lane highways), wide paved shoulders, and extra-wide highways are designed to enhance traffic operations on two-lane highways. These low-cost improvements bridge the gap between conventional two-lane highways and four-lane highways. This paper compares design practices and policies as well as the operational experience regarding passing lanes, wide paved shoulders, and extra-wide two-lane highways. Canadian and German warrants for upgrading a two-lane highway to a passing lane system and ultimately a four-lane motorway are examined. Geometric design standards for cross-section elements such as lane width and shoulder width are compared. Design standards for the length and spacing of passing lanes as well as the length of merge and diverge tapers are examined. Design practices and policies concerning transition areas between, for example, conventional two-lane and extra-wide highways are discussed. The signing and marking practices for passing lanes, extra-wide highways and transition areas are also included in the paper. The paper discusses the operational experience in terms of overtaking rates, speed-volume relationships, platooning, level-of-service, accident rates, and driver attitudes. Research studies in both Canada and Germany show that passing lanes, wide-paved shoulders, and extra-wide highways increase the quality of service and decrease the accident rates compared to conventional two-lane highways. Both Canadian and German studies have concluded that passing lanes and extra-wide highways offer a cost-effective alternative of enhancing the quality of service and safety on those two-lane highways that do not meet the warrants for motorways or where cost and environmental concerns rule out the four lane option.

• Record URL:
  http://onlinepubs.trb.org/onlinepubs/circulars/ec003/toc.pdf
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• 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

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  Washington, DC  United States  20001
• Authors:
  • Frost, U
  • MORRALL, J
• Conference:
  • International Symposium on Highway Geometric Design Practices
  • Location: Boston, Massachusetts
  • Date: 1995-8-30 to 1995-9-1
• Publication Date: 1998-1

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 34:1-15
• Serial:
  • Transportation Research Circular
  • Issue Number: E-C003
  • Publisher: Transportation Research Board
  • ISSN: 0097-8515

Subject/Index Terms

• TRT Terms: Attitudes; Cost effectiveness; Crash rates; Cross sections; Design practices; Design standards; Geometric design; Highway operations; Highway safety; Level of service; Passing lanes; Paved shoulders; Road markings; Road shoulders; Speed volume relationships; Traffic lanes; Traffic platooning; Traffic signs; Two lane highways; Width
• Uncontrolled Terms: Extra-wide highways; Passing lane length; Passing lane spacing; Pavement transition areas; Warrants (Highway upgrading)
• Geographic Terms: Canada; Germany
• Subject Areas: Design; Highways; Planning and Forecasting; I21: Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00794691
• Record Type: Publication
• Report/Paper Numbers: E-C003
• Files: TRIS, TRB, ATRI
• Created Date: Jun 12 2000 12:00AM