• Urban Applications of Innovative Intersection Designs

    NCDOT Research Project Number: 2021-11

 Executive Summary

  • Communities across North Carolina want to create walkable mixed-use development along state highways, but they do not trust that NCDOT can convert today’s auto-oriented major arterials into “Complete Streets” with sufficient ambiance to catalyze the walkable development they desire. To a large extent they are correct: the agency is not “well practiced” in how to deliver products that can catalyze walkable environments. But even if NCDOT can organize to support that objective, there is still a major engineering challenge: How to do it? Are there any tools available that can manage high traffic volumes with reasonable travel times, and at the same time create an environment that will catalyze walkable development? Are there tools that can help us to drive slower, but travel the same if not faster, through an impressively walkable environment?
    2021-11 Quadrant Concept.jpg
    This report focuses on three “Placemaking Alternative Intersection” families (PAIs) that can serve as the “bone structure” for that outcome: Quadrant, U-Turn, and One-Way Split Intersections. Using real-world locations in Greenville and Smithfield, NC, this report showcases both graphical and technical analysis to demonstrate that it is possible to manage much higher, urban-scale volumes of traffic, in ways that can catalyze the urban scales of development that communities desire due to the walkability of the result. The research team created an excel-based “Development Scale Calculator” to determine how much development an intersection area can
    support based on the vehicular capacity of the intersection design, and the “capacity equivalent” provided by alternative modes, connectivity, and internal capture based on density and diversity of uses. We conducted two focus groups with community stakeholders and experts in the field to weigh in on our diagrams and findings. They confirm that these PAI designs, combined with other actions such as form-based zoning, are highly likely to catalyze the walkable urban environments that communities desire.​

Christopher Cunningham
Christopher Cunningham; Michael R. Brown; Celen Pasalar; Guangchuan Yang; Yanhua Lu
Joseph E. Hummer
John W. Kirby
NC State University - ITRE

 Report Period

  • January 1, 2021 – August 31, 2023


  • Complete


  • Traffic, Mobility, Safety and Roadway Design

 Sub Category

  • Facility Design

 Related Links

Was this page helpful?