Roundabouts in Corridors: Case Studies and Applications


As part of Kittelson & Associates’ ongoing Transportation Education Series (TES), Lee Rodegerdts will be co-presenting a session with Dina Swires of the Washington State Department of Transportation on the application of roundabouts in corridors. The presentation will provide an overview of recent national research on the applications of corridors of roundabouts, defined as three or more roundabouts in series, as well as a case study for a rural roundabout corridor in Whatcom County, Washington.

The first part of the presentation and discussion will be led by Lee and will focus on the recent research that Lee led for the National Cooperative Highway Research Program in NCHRP Report 772 (NCHRP Project 03-100): Evaluating the Performance of Corridors with Roundabouts. Topics include the following:

  1. Examples of the variety of roundabout corridor applications throughout the United States
  2. Lessons learned by corridor operators during their projects’ development and implementation
  3. Project development and evaluation tools developed and presented in NCHRP Report 772, including:

    a. Travel time estimation through a series of roundabouts, and
    b. A corridor comparison framework for evaluating new potential corridors

In the second part of the presentation, Dina will present a case study of the Guide Meridian Roundabout Corridor, SR 539, in Whatcom County, Washington. This highway is a popular freight route for semi-trucks, and is a direct link to the USA/Canada Border crossing at Lynden/Aldergrove. Approximately 20,000 drivers use Guide Meridian on a daily basis north of Bellingham. WSDOT transformed the Guide Meridian from a narrow two-lane roadway to a wider and safer four-lane highway. WSDOT also divided the highway with a median cable barrier, and built four roundabouts at key intersections to further improve safety. Construction began in 2008 and was completed in 2010. It is one of the first, and currently the only, managed access rural roundabout corridors of its size in the country.

This presentation is tailored towards engineers, planners, and policymakers. The presentation will be followed by an opportunity for questions and an interactive discussion.

8:00 to 8:30 a.m. - Check-in/Breakfast
8:30 to 9:40 a.m. – Presentation
9:40 to 10:00 a.m. - Question & Answer Session

Participants will earn a total of 1.5 professional development hours (PDH) for attending this workshop. AICP Certification Maintenance: Kittelson & Associates, Inc. has applied for AICP Certification Maintenance credits. Pending approval, the Roundabouts TES will be eligible for 1.5 hours of CM credits.

There is no cost to attend this workshop and breakfast will be provided.

If you have any questions regarding this event, please contact Norma Jensen at (503) 228-5230 or

We look forward to seeing you there!

Event Materials