A COMPARISON OF THE SAFETY POTENTIAL OF THE RAISED VERSUS DEPRESSED MEDIAN DESIGN

This paper examines the safety benefits of the mound (raised) median design as compared to the swale (depressed) median design for Interstate highway medians having an 84-ft (25.60m) design width. The effects of each median design on the frequency and severity of median-involved single- vehicle accidents, on the path of the encroaching vehicle, and on the vehicle's tendency to overturn were studied. Approximately 130 miles (209 km) of 4-lane, divided highway with each median design were studied, and the accident experience from 1969 through 1971 was analyzed. The results indicated that the 84-ft median of either cross-sectional design provides a generally adequate recovery area for encroaching vehicles, although the swale median appears to provide more opportunity for encroaching vehicles to regain control and return to their roadway. The use of either cross-sectional design for medians of this width has no effect on the primary path of the vehicle, on the vehicle's tendency to overturn, or on the resulting severity of the accident when a median encroachment results in a reported accident.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1974/514/514-001.pdf
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=A+COMPARISON+OF+THE+SAFETY+POTENTIAL+OF+THE+RAISED+VERSUS+DEPRESSED+MEDIAN+DESIGN&author=T.+Foody&author=T.+Culp&publication_year=1974
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• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Operational Effects of Geometrics. 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:
  • Foody, Thomas J
  • Culp, Thomas B
• Discussers:
  • Anderson, H L
  • Glennon, John C
• Conference:
  • 53rd Annual Meeting of the Highway Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1974-1-21 to 1974-1-25
• Publication Date: 1974

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 1-15
• Monograph Title: Traffic operations
• Serial:
  • Transportation Research Record
  • Issue Number: 514
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Crash rates; Crash severity; Design; Medians; Safety; Single vehicle crashes
• Old TRIS Terms: Median encroachments
• Subject Areas: Design; Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 00083966
• Record Type: Publication
• ISBN: 0309023580
• Files: TRIS, TRB
• Created Date: Apr 8 1975 12:00AM