Groundwork for the Second Edition of the Alternative Intersection and Interchange Informational Report

Alternative Intersection and Interchange (AII) designs are those which provide an innovative approach to the geometric or control features which may improve operations and/or safety for different road users. In 2010, the U.S. Federal Highway Administration (FHWA) published the first edition of "Alternative Intersections/Interchanges: Informational Report" (AIIR), which provided information on six alternative treatments including: displaced left turn (DLT) intersections, restricted crossing U-turn (RCUT) intersections, median U turn (MUT) intersections, quadrant roadway (QR) intersections, double crossover diamond (DCD) interchanges, and DLT interchanges. For each treatment, the report provides detailed information in a standardized format, including salient geometric design features, operational and safety issues, access management, costs, construction sequencing, environmental benefits, and applicability. This report has been used by various agencies and has proven to be a valuable resource for planning and designing AIIs; however, there are still unconventional design concepts that have not been fully explored and some of the current ones could use updates. During the past decade, there have been an increasing number of AIIs installed in the United States, and additional new AII designs that are not documented in the AIIR first edition have emerged since 2010. Examples of these designs include Reverse RCUTs, Partial Median U-turns, and Grade-Separated Alternative Intersections. These new AII designs may involve different traffic patterns, which may introduce confusion and create new safety hazards for drivers. This research will provide a state-of-the-practice literature review and expert interviews on AII designs, draft an annotated outline for the AIIR second edition, and provide supplemental tools to help planners and engineers select site-specific AII's during the project planning and design process.

Language

  • English

Project

  • Status: Active
  • Funding: $99,875
  • Contract Numbers:

    2022-15

  • Sponsor Organizations:

    North Carolina Department of Transportation

    Research and Development
    1549 Mail Service Center
    Raleigh, NC  United States  27699-1549
  • Managing Organizations:

    North Carolina Department of Transportation

    Research and Development
    1549 Mail Service Center
    Raleigh, NC  United States  27699-1549
  • Project Managers:

    Bolyard, Stephanie

  • Performing Organizations:

    North Carolina State University, Raleigh

    Institute for Transportation Research and Education
    Campus Box 8601
    Raleigh, NC  United States  27695-8601
  • Principal Investigators:

    Cunningham, Christopher

  • Start Date: 20210801
  • Expected Completion Date: 20221222
  • Actual Completion Date: 0
  • USDOT Program: Research and Development

Subject/Index Terms

Filing Info

  • Accession Number: 01778726
  • Record Type: Research project
  • Source Agency: North Carolina Department of Transportation
  • Contract Numbers: 2022-15
  • Files: RIP, STATEDOT
  • Created Date: Aug 5 2021 12:55PM