Guidelines for Use of Left-Turn Lanes and Signal Phases

Details

• Creators:
  Lin, Han-Jei ; Machemehl, Randy B. ; Lee, Clyde E. ; Herman, Robert
• Corporate Creators:
  University of Texas at Austin. Center for Transportation Research
• Corporate Contributors:
  Texas State Department of Highways and Public Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Guidelines Left-turn Bay Left Turns Separate Phase Signalized Intersections Simulation Traffic Actuated Controllers Traffic Delays Traffic Signal Phases Transparency Vehicular Delay

  More +
• Publication/ Report Number:
  FHWA/TX-84/07+258-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas ; United States
• Edition:
  Interim
• Corporate Publisher:
  Texas Transportation Institute. Texas A&M University
• Abstract:
  At signalized intersections, the common treatment for improving left-turn performance is to increase left-turn capacity by installing a left-turn bay or a separate left-turn phase. However, in a given traffic condition and geometric configuration, there have been no universal guidelines for ascertaining the need for a left-turn treatment. In this research, the TEXAS Simulation Model is employed to study the capacity and performance for left-turn movements at signalized intersections in order to explore warrants for left-turn treatments. Since 1eftturn performance is germane to left-turn capacity, existing methods for estimating left-turn capacity are thoroughly reviewed. After recognizing inadequacies in existing methods, a new method which can yield reasonable estimates for left-turn capacity under general conditions of left-turn movements is proposed. Furthermore, different measures of effectiveness are used to evaluate the performance of 1eftturn movements under various traffic conditions. With a set of delay criteria, critical conditions of left-turn movements are identified. Finally, a new capacity warrant is derived based on the relation between the critical left-turn volume and left-turn capacity.
• Format:
  PDF
• Funding:
  3-18-80-258
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:b7a41ef79cba2f183fcf5174580b3d597d33fe32ffd0e231009905ffbbaa696152eaa9db83270aee7c4c6eec61ac4212feb04800aee0e7799300b0ec16c160cd
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/85705/dot_85705_DS1.pdf
• File Type:
  [PDF - 4.25 MB ]