While full-sized roundabouts are a proven solution for addressing safety and mobility at intersections, their costs have risen relative to other intersection control types, prompting interest in lower-cost alternatives. TRB hosted a webinar on Thursday, June 25, 2026 from 11:00 AM to 12:30 PM Eastern that explored how highway agencies are planning, designing, and implementing mini and modular roundabouts as cost-effective intersection solutions. Presenters highlighted mini roundabout use on higher-speed rural roadways and near schools, where they can efficiently manage peak traffic flows and improve safety. Presenters also examined the limited but growing use of modular roundabouts, including the contexts in which they have been deployed and the challenges affecting broader adoption.
This webinar was based on NCHRP Project 20-68, Domestic Scan 23-01: Experiences in the Use of Mini and Modular Roundabouts by Highway Agencies.
This webinar was sponsored by TRB’s National Cooperative Highway Research Program.
The slides are available. 
 
Webinar agenda and presenters

• Fundamentals of mini roundabouts – Laura Nesbitt, Jacobs
• Fundamentals of modular roundabouts – Joseph Hummer, North Carolina Department of Transportation
• Minnesota’s approach to mini roundabouts in downtown and snow conditions – Gwen Mei, Minnesota Department of Transportation
• Question and answer session moderated by Hillary Isebrands, Federal Highway Administration

The first 60 minutes of the webinar were for presentations and the final 30 minutes were reserved for audience questions.
 
Learning Objectives
At the end of this webinar, participants can:

• Distinguish mini and modular roundabouts from other types
• Describe the general status of mini and modular roundabouts around the U.S.
• Identify the conditions appropriate for a mini or modular roundabout location

 
Professional Development Hours
This webinar was delivered as a scheduled – e-learning live event and is categorized within RCEP as Technical, Health and Safety.
Professional Development Hours (PDHs) earned on completion of this program were reported to the Registered Continuing Education Program (RCEP). Certificates of Completion are issued to all participants via the RCEP.net online system. Complaints about registered providers may be addressed to RCEP, 1015 15th Street, NW, 8th Fl., Washington, DC, 20005.
American Institute of Certified Planners Certification Maintenance Credits
This webinar was approved by the American Planning Association (APA) for 1.5 Certification Maintenance (CM) Credits. CM credits provide continuing education opportunities for AICP Certified Planners to continue their professional skills and knowledge. To receive CM credits, Certified Planners should visit the TRB event webpage on American Planning Association and register their participation. If you have problems reporting your CM credits or have general questions about the CM program, please contact the APA.