ACCIDENT EFFECTS OF SIDESLOPE AND OTHER ROADSIDE FEATURES ON TWO-LANE ROADS

The purposes of this study were to (1) develop one or more methods for quantifying roadside hazard, (2) define factors that influence run-off-road accidents, and (3) estimate the accident benefits of various roadside improvements. Detailed traffic, accident, roadway, and roadside data were collected on 4,951 miles of two-lane rural roads in seven states. Roadside data included development and use of a pictorial seven-point roadside hazard scale, a measure of roadside recovery (clear zone) distance, field sideslope measurements, and detailed types of and lateral distances to roadside obstacles. Statistical testing was used along with log-linear modeling to determine the interactive effects of roadside and roadway features on accidents. Flatter sideslopes of 3:1 to 7:1 were found to be related to lower rates of single-vehicle accidents. However, only a 2 percent reduction in single-vehicle accidents was found for a 3:1 sideslope compared to a 2:1 sideslope. Reductions in related accidents due to general roadside improvements were found to range from 19 percent to 52 percent, depending on the amount of roadside improvement. Trees and utility poles are the roadside objects most often struck. Obstacles associated with the highest percent of severe accidents include culverts, trees, utility and light poles, bridges, rocks, and earth embankments.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1988/1195/1195-004.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=ACCIDENT+EFFECTS+OF+SIDESLOPE+AND+OTHER+ROADSIDE+FEATURES+ON+TWO-LANE+ROADS&author=C.+Zegeer&author=D.+Reinfurt&author=W.+Hunter&author=J.+Hummer&author=R.+Stewart&author=L.+Herf&publication_year=1988
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  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309047609
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1195, Geometric Design and Operational Effects. 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:
  • Zegeer, Charles V
  • Reinfurt, Donald W
  • Hunter, William W
  • Hummer, Joseph
  • Stewart, Richard
  • Herf, Lynne
• Publication Date: 1988

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 33-47
• Monograph Title: Geometric design and operational effects
• Serial:
  • Transportation Research Record
  • Issue Number: 1195
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Bridges; Clear zones; Crashes; Culverts; Embankments; Hazards; Mathematical models; Ran off road crashes; Roadside; Roadside improvement; Rocks; Rural highways; Safety; Single vehicle crashes; Slopes; Traffic safety; Trees; Two lane highways; Utility poles
• Uncontrolled Terms: Fixed object; Side slopes
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 00489688
• Record Type: Publication
• ISBN: 0309047609
• Files: TRIS, TRB, ATRI
• Created Date: Nov 30 1989 12:00AM