Updated Guidance on Reduced Left-Turn Conflict Intersections

Since the publication of the Alternative Intersections/Interchanges: Informational Report (AIIR) by FHWA in 2009, and the Median U-Turn (MUT) and Restricted Crossing U-Turn (RCUT) informational guides in 2014, dozens of state and local agencies have built these intersections in many different contexts, with valuable experience to share. Several agencies have done formal evaluations and documented their performances. However, this collective experience and knowledge has not been reflected in an updated, comprehensive informational guide. Similar updates to comparable informational guides, such as NCHRP Research Report 1043: Guide for Roundabouts (2023) and NCHRP Research Report 959: Diverging Diamond Interchange Information Guide; Second Edition (2021), have proven quite successful, with information from these guides having a profound impact on the state of the practice, eventually influencing updates of the AASHTO Green Book. The objective of this project is to (1) conduct a systematic review and analysis of emerging alternative intersection and interchange concepts and their variations to understand the latest knowledge, practices, and lessons learned, and (2) develop a report that will focus on updated traffic safety and multimodal elements in planning, analyzing, designing, operating, and evaluating alternative intersections and interchanges.


  • English


  • Status: Proposed
  • Funding: $600000
  • Contract Numbers:

    Project 17-131

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Zhao, Yi

  • Start Date: 20240520
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01919348
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-131
  • Files: TRB, RIP
  • Created Date: May 22 2024 12:59PM