North Carolina Department of Transportation
Research & Innovation Summit – 2021

Mini Roundabout CMF Development

Authors: Raunak Mishra, M.Tech., Sonu Mathew, Ph.D., & Srinivas S. Pulugurtha, Ph.D., P.E., F.ASCE
University of North Carolina at Charlotte
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  • Mini roundabouts are common in the United Kingdom and many European countries
  • Featured designs for slowing traffic, improving intersection safety, and reducing delay at minor approaches
  • Characteristics
    • Inscribed circle diameter 45 to 90 feet
    • Central island is traversable
    • Cost of a mini roundabout is about 1/3rd of a full sized roundabout and has fewer right of way impacts
  • FHWA recommends mini roundabouts at speed limit 35 mph or lower
  • Lack of documented evidence pertaining to safety benefits associated with mini roundabout construction at approaches with speed limit 35 mph or higher


For questions about this research, contact Srinivas Pulugurtha at