Guidelines for left-turn phase utilization do not generally include recommendations for left-turn signal phase sequence patterns. In this research, the TEXAS Simulation Model is employed to study the effects of various left-turn sequence patterns on traffic operations in order to establish guidelines for utilization of most typical sequence patterns. Recent literature on the effects of left-turn sequence patterns on intersection delay and accidents is reviewed. With vehicular delay as a basis for comparison, protected only and protected/permissive left-turn phasing are studied with pretimed control. Dual leading and dual lagging left-turn phase sequences are also studied when both are supplemented by permissive turning and pretimed control. Furthermore, split, dual, and composite sequences are compared for the pretimed case. The examination of basic phase sequencing schemes under actuated signal control essentially duplicates that for pretimed control. Finally, guidelines for the implementation of phase sequence patterns are presented. (Author)

  • Supplemental Notes:
    • Research conducted in cooperation with the Federal Highway Administration Research Study Title: Warrants for Left-Turn Lanes and Signal Phases (Actuated Controllers).
  • Corporate Authors:

    University of Texas, Austin

    Center for Transportation Research, 3208 Red River Street
    Austin, TX  United States  78705

    Texas State Department of Highways & Public Transportation

    Transportation Planning Division, P.O. Box 5051
    Austin, TX  United States  78763

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Machemehl, R B
    • Mechler, A M
  • Publication Date: 1983-11

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 48 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00390999
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-TX-84-48+258-2 Intrm Rpt.
  • Contract Numbers: Res Study3-18-80-258
  • Created Date: Jan 30 1985 12:00AM