GUIDELINES FOR USE OF LEADING AND LAGGING LEFT-TURN SIGNAL PHASING

The use of optimum phase sequences at signalized intersections could save motorists many hours of delay and could result in fewer accidents. However, very little factual information has been available to guide engineers in choosing between the various signal phasing alternatives. To close that gap, leading and lagging signal sequences were evaluated in Indiana using a survey of licensed drivers, an examination of traffic conflicts, an analysis of accident records, and a simulation model of traffic flow. The guidelines developed as a result of these activities generally reflect the advantages documented for lagging sequences over leading sequences in a variety of situations. Lagging sequences are recommended for, among other situations, intersections serving heavy pedestrian volumes, diamond interchanges or one-way pairs, and intersections with fixed-time signals. However, when implementing lagging sequences, caution is recommended to prevent situations in which a vehicle could become "trapped" in an intersection as the green phase elapses.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 11-20
  • Monograph Title: Communications, traffic signals, and traffic control devices, 1991
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00622200
  • Record Type: Publication
  • ISBN: 0309051703
  • Files: TRIS, TRB, ATRI
  • Created Date: May 31 1992 12:00AM