ANALYSIS OF VEHICLE OPERATIONS ON HORIZONTAL CURVES

A study was conducted to quantify the effects of horizontal curve features on such operational variables as changes in vehicle speeds and vehicle encroachments over the centerline and edgeline. This information was considered important in determining curve design criteria that would lead to effective safety and operational improvements at current curve sites. The data included geometric, traffic, and operational measures from a data base of 78 curve sites in New York State. Various statistical procedures were used, including linear regression analyses, analyses of operations by differing groups of geometric conditions, residual analyses, and locally weighted nonparametric regression. It was found that, as curves become sharper, there is a proportionally greater increase in speed reduction and edgeline encroachments on the inside lane (i.e., the lane on a curve where the motorist must steer to the right). Centerline encroachments in the outside lane increase more drastically than those on the sharper curves to the right. These findings support the contention of drivers cutting the curve short, which can result in run-off-road crashes on the inside of the curve as well as head-on and opposite-direction-sideswipe crashes with oncoming motorists. Appropriate curve design guidelines are discussed that may help to minimize these operational and potentially accident-related trends.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1991/1318/1318-006.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=ANALYSIS+OF+VEHICLE+OPERATIONS+ON+HORIZONTAL+CURVES&author=D.+Reinfurt&author=C.+Zegeer&author=B.+Shelton&author=T.+Neuman&publication_year=1991
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1318, Highway Systems, Human Performance, and Safety 1991. 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:
  • Reinfurt, Donald W
  • Zegeer, Charles V
  • Shelton, Brent J
  • Neuman, Tim
• Publication Date: 1991

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 43-50
• Monograph Title: Highway systems, human performance, and safety, 1991
• Serial:
  • Transportation Research Record
  • Issue Number: 1318
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Curves (Geometry); Design; Frontal crashes; Geometric design; Linear regression analysis; Motor vehicles; Ran off road crashes; Regression analysis; Right of way (Land); Side crashes; Speed; Traffic speed
• Uncontrolled Terms: Design criteria; Horizontal curvature
• Old TRIS Terms: Encroachments
• Subject Areas: Data and Information Technology; Design; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 00621661
• Record Type: Publication
• ISBN: 0309051584
• Files: TRIS, TRB, ATRI
• Created Date: Apr 30 1992 12:00AM