EFFECTIVENESS OF CLEAR RECOVERY ZONES (DISCUSSION, CLOSURE)

Clear recovery zones outside the highway shoulder provide an opportunity for vehicles that leave the roadway to come to a safe stop or to return to the roadway. The results of a research effort to determine the effectiveness of clear recovery zones in reducing the number and severity of run-off-the-road (ROR) accidents ant to provide an approach for the cost-effective application of clear recovery zones are presented. Actual accident data were obtained and analyzed to compare three different roadside design policies: the 6:1 clear zone policy, the 4:1 clear zone policy, and the nonclear zone policy. Three highway types were also considered: two-lane highways, four-lane freeways, and four-lane divided nonfreeways. Road sections that had these highway types and roadside design policies were identified in Illinois, Minnesota, and Missouri. Analysis of the accident data for the study sections revealed that roadside design policy had a statistically significant relation to single-vehicle ROR accident rate for all of the highway types studied. The differences in the accident rate between roadside design policies were quantified for each highway type. An analysis of the severity of single-vehicle ROR accidents revealed that the severity distribution did not vary between the roadside design policies on any of the three highway types studied. Four design examples were developed in order to illustrate the cost-effectiveness implications of the safety effectiveness measures developed in the study. The examples compared the accident reduction benefits and typical construction costs for improving highways from one roadside design policy to another. (Author)

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1983/923/923-013.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=EFFECTIVENESS+OF+CLEAR+RECOVERY+ZONES+(DISCUSSION%2C+CLOSURE)&author=J.+Graham&author=D.+Harwood&publication_year=1983
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03611981
• 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
• Corporate Authors:

  Transportation Research Board

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• Authors:
  • Graham, Jerry L
  • Harwood, Douglas W
• Discussers:
  • Mulinazzi, Tom
  • Hall, J W
• Publication Date: 1983

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 72-86
• Monograph Title: HIGHWAY GEOMETRICS, INTERACTIVE GRAPHICS, AND LASER MAPPING
• Serial:
  • Transportation Research Record
  • Issue Number: 923
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Benefit cost analysis; Cost effectiveness; Crash severity; Ran off road crashes; Road shoulders; Roadside; Safety; Traffic safety
• Old TRIS Terms: Clear recovery zones
• Subject Areas: Design; Highways; Planning and Forecasting; Safety and Human Factors; I21: Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00390069
• Record Type: Publication
• ISBN: 0309036127
• Report/Paper Numbers: HS-037 060
• Files: TRIS, TRB
• Created Date: Nov 30 1984 12:00AM