TRAFFIC OPERATIONS STUDY OF THE TURNING LANES ON UNCONTROLLED APPROACHES OF RURAL INTERSECTIONS

A time-lapse film study of the traffic operations on 14 intersection approaches on rural two-lane highways in Nebraska was conducted. The purpose of the study was to evaluate the safety effects of turning lanes on the uncontrolled approaches of intersections on rural two-lane highways. The turning lanes evaluated were left-turn, right-turn, and fly-by lanes. Traffic operations on the approaches with turning lanes were compared with those on similar approaches without turning lanes to determine the safety effects of the turning lanes. The measures of safety effectiveness used in the study were (a) standard deviation of mean approach speed, (b) traffic conflict rate, (c) frequency of abnormal turning maneuvers, and (d) improper lane utilization. Lower values of these measures were assumed to be indicative of safer traffic operations. The results of the study indicated that the provision of turning lanes on uncontrolled approaches of intersections on rural two-lane highways improved the safety of traffic operations on these approaches, especially those without paved shoulders. It was also apparent from the results of the study that consideration must be given to the adequate design of these lanes, particularly left-turn and fly-by lanes, in order to eliminate their improper use and encroachments by turning vehicles on adjacent through lanes, which negate the safety benefits provided by such lanes.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1986/1100/1100-001.pdf
• Summary URL:
  • https://scholar.google.com/scholar_lookup?title=TRAFFIC+OPERATIONS+STUDY+OF+THE+TURNING+LANES+ON+UNCONTROLLED+APPROACHES+OF+RURAL+INTERSECTIONS&author=P.+McCoy&author=W.+Hoppe&publication_year=1986
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/030904121X
• 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:
  • McCoy, Patrick T
  • Hoppe, Weldon J
• Publication Date: 1986

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 1-9
• Monograph Title: Design and operational effects of geometrics
• Serial:
  • Transportation Research Record
  • Issue Number: 1100
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Design; Highway operations; Highway safety; Measures of effectiveness; Rural highways; Traffic; Turning lanes; Unsignalized intersections
• Subject Areas: Design; Highways; Operations and Traffic Management; Planning and Forecasting; I21: Planning of Transport Infrastructure; I73: Traffic Control;

Filing Info

• Accession Number: 00472637
• Record Type: Publication
• ISBN: 030904121X
• Files: TRIS, TRB
• Created Date: Aug 31 1987 12:00AM