OPERATIONAL COMPARISON OF LEADING AND LAGGING LEFT TURNS

Field studies were conducted in the Phoenix and Tucson metropolitan areas for the purpose of comparing the operational differences between leading and lagging left-turn signal phases. Delay studies were conducted in both areas at isolated intersections, and the influence on signal system progression was evaluated at three locations in the Phoenix area. In both areas, the lagging left-turn phases do not utilize overlaps even though phase overlaps were used with the leading left-turn operations. Intersections with protected-only as well as protected-plus-permissive left turns were included. The study involved a before-and-after analysis of the intersection as well as arterial operations. For the individual intersections, the field studies found that the intersection delay is significantly greater with the lagging left-turn operation. This finding was true for both of the metropolitan areas. In terms of the signal system progression, no significant differences were found in progression among the leading, lagging, and mixed operations.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1993/1421/1421-001.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=OPERATIONAL+COMPARISON+OF+LEADING+AND+LAGGING+LEFT+TURNS&author=J.+Lee&author=R.+Wortman&author=D.+Hook&author=M.+Poppe&publication_year=1993
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309055741
• 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:
  • Lee, Jim C
  • Wortman, Robert H
  • Hook, David J P
  • Poppe, Mark J
• Publication Date: 1993

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 1-10
• 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: Arterial highways; Before and after studies; Exclusive permissive phasing; Exclusive phasing; Field studies; Isolated intersections; Lagging (Earthwork); Left turn phase; Streets; Traffic delays; Traffic signal control systems
• Geographic Terms: Phoenix (Arizona); Tucson (Arizona)
• Old TRIS Terms: Lagging; Leading; Left turn phasing; Signal systems
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00647261
• Record Type: Publication
• ISBN: 0309055741
• Files: TRIS, TRB
• Created Date: May 2 1994 12:00AM