Guide for Pedestrian and Bicycle Safety at Alternative Intersections and Interchanges (A.I.I.)

The objective of this research is to develop a guide for transportation practitioners to improve and integrate pedestrian and bicycle safety considerations at alternative intersections and interchanges (AII) through planning, design, and operational treatments that (1) identifies and evaluates current practices, and emerging technologies and trends, in the U.S. and internationally; (2) describes current best practices for measuring the effectiveness of such AII treatments; (3) evaluates the safety and operational outcomes of specific AII treatments; and (4) identifies and ranks treatments for typical types of projects. The primary focus of the research is roadway functional classifications of collector and above. The approaches to evaluate pedestrian and bicycle treatments can be separate, but implementation of the treatments should be coordinated. The guide should address a broad range of issues related to improved pedestrian and bicycle safety at AII such as, but not limited to, the following: (1) Describing new and emerging AII designs (e.g., Diverging Diamond Interchanges (DDI), Displaced Left-Turn (DLT) or Continuous Flow (CFI) intersections, Restricted Crossing U-Turn (RCUT) intersections, Median U-Turn (MUT) intersections, Quadrant Roadway (QR) intersections) and evaluating their impacts on pedestrians and bicyclists; (2) Documenting domestic and international best practices for integrating pedestrian and bicyclist movements into AII designs; (3) For each AII type, documenting key considerations such as wayfinding, accommodation for pedestrians with disabilities (including visually and hearing impaired), delay for pedestrians and cyclists, and safety for pedestrians and cyclists; (4) Documenting benefits and trade-offs of pedestrian and bicycle AII design and operational treatments; (5) Developing a design and operational matrix for evaluating, selecting, and incorporating pedestrian and cyclist safety considerations for AII treatments; (6) Designing and implementing one or more approaches (e.g., simulation, case studies, modeling, scenario planning) to evaluate the impacts of AII on pedestrian and bicyclist behavior; and (7) Providing a foundation for future data collection to produce Crash Modification Factors (CMFs). While the guide should be directly applicable to most situations, it should also outline decision-making processes and criteria that would assist agencies in identifying flexible solutions.

  • Record URL:
  • Supplemental Notes:
    • STATUS NCHRP 07-25 has been published as NCHRP Report 948 Guide for Pedestrian and Bicyclist Safety at Alternative and Other Intersections and Interchanges. The report is available at An implementation project for Report 948 is conducted under NCHRP 20-44(35), found at


  • English


  • Status: Completed
  • Funding: $400000
  • Contract Numbers:

    Project 07-25

  • Sponsor Organizations:

    National Cooperative Highway Research Program

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

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Performing Organizations:

    Kittelson & Associates

  • Principal Investigators:

    Schroeder, Bastian

  • Start Date: 20170412
  • Expected Completion Date: 20191231
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01881807
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 07-25
  • Files: TRB, RIP
  • Created Date: May 1 2023 5:59PM