SELECTION CRITERIA FOR LEFT-TURN PHASING AND INDICATION SEQUENCE

The development of guidelines and recommendations for the selection of left-turn phasing and indication sequences at signalized intersections is documented in this paper. The guidelines developed are based on field studies and use easy-to-obtain data for the selection process. A simple three-level decision process regarding the most suitable left-turn phasing treatment to be used is established. The process favors the least restrictive permissive left-turn phase unless traffic and geometric conditions warrant the more restrictive protected/permissive or protected-only phasings. These guidelines are based on threshold values designed to determine what constitutes an excessive value for any particular variable, beyond which more restrictive left-turn phasing treatments may be justified. The guidelines developed also reflect a selection process that recognizes the trade-off between operational efficiency and safety. The study shows that selection of a particular phase is a multiobjective process involving a number of factors, and in many cases more than one condition must be met to justify the selection of a particular phase that will ensure an optimal solution.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1993/1421/1421-002.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=SELECTION+CRITERIA+FOR+LEFT-TURN+PHASING+AND+INDICATION+SEQUENCE&author=S.+Asante&author=S.+Ardekani&author=J.+Williams&publication_year=1993
• Availability:
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1421, Traffic Control Devices, Visibility, and Traffic Signal Systems. 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:
  • Asante, Seth A
  • Ardekani, Siamak
  • Williams, James C
• Publication Date: 1993

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 11-20
• Monograph Title: Traffic control devices, visibility, and traffic signal systems
• Serial:
  • Transportation Research Record
  • Issue Number: 1421
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Alternatives analysis; Exclusive permissive phasing; Exclusive phasing; Guidelines; Left turn phase; Permissive phasing; Traffic safety
• Uncontrolled Terms: Operational efficiency
• Old TRIS Terms: Left turn phasing
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00647262
• Record Type: Publication
• ISBN: 0309055741
• Files: TRIS, TRB
• Created Date: May 2 1994 12:00AM