DESIGN CONSIDERATIONS FOR HIGHWAY REVERSE CURVES

Existing sight distance models of highway horizontal (vertical) curves are applicable only to simple circular (parabolic) curves. These simple models may greatly overestimate the lateral clearance needs for reverse horizontal curves and the curve length requirements for reverse vertical curves. No available analytical model quantifies the effects of the alignment reversal on sight distance characteristics. The geometric and sight distance characteristics of reverse horizontal and vertical curves are presented. For reverse horizontal curves the available sight distance is related to the parameters of the two circular arcs, the length of the common tangent, the locations of the driver and object, and the location of the vision-limiting obstacle. The obstacle may be located within the circular arcs or the common tangent. For reverse vertical curves the available sight distance is related to the parameters of the crest and sag arcs, the length of the common tangent, the locations of the driver and object, and their heights. The sight-hidden zone (dip) that may exist on a reverse horizontal (vertical) curve is examined. The sight distance profiles and minimum sight distances of reverse and simple curves are compared.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1994/1445/1445-001.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=DESIGN+CONSIDERATIONS+FOR+HIGHWAY+REVERSE+CURVES&author=S.+Easa&publication_year=1994
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309060516
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1445, Cross Section and Alinement Design Issues. 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
• Authors:
  • Easa, Said M
• Publication Date: 1994

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 1-11
• Monograph Title: Cross section and alinement design issues
• Serial:
  • Transportation Research Record
  • Issue Number: 1445
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Alignment; Geometric design; Highway curves; Sight distance
• Uncontrolled Terms: Horizontal curvature; Vertical curvature
• Subject Areas: Design; Highways; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00675325
• Record Type: Publication
• ISBN: 0309060516
• Files: TRIS, TRB, ATRI
• Created Date: Mar 20 1995 12:00AM