Guidelines for Design and Operation of U-turns

U-turn lanes are commonly provided at diamond interchanges to reduce delay for U-turning traffic and for the interchange as a whole; however, there are currently many unknowns related to their design, operation, and use. This project provides Texas Department of Transportation (TxDOT) with implementable guidelines for designing and operating U-turn lanes at diamond interchanges. The research team will identify and investigate demand and capacity factors affecting U-turn lane use, determine the capacity of U-turn lanes under various geometric and operational conditions, and determine the anticipated effectiveness of proposed solutions to U-turn operational issues. The research team will structure these guidelines for inclusion in the Roadway Design Manual and other manuals dealing with access management, design, and operations of facilities. This project will also provide a cross-sectional safety analysis of existing U-turn configurations. The research team will provide a self-calculating spreadsheet tool as a key product of the safety analysis that can be used to predict U-turn safety performance under a variety of conditions.


  • English


  • Status: Completed
  • Contract Numbers:


  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Jensen, Darrin

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Tydlacka, Jonathan

  • Start Date: 20150901
  • Expected Completion Date: 20170831
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01619638
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-6894
  • Files: RiP, STATEDOT
  • Created Date: Dec 21 2016 12:33PM