Circumventing Gridlock

When does an intersection warrant a roundabout? Does the intersection have enough space for a roundabout? How do we keep traffic moving through the intersection during construction? Those and many other questions are asked by agencies who explore roundabouts as an option. Cities and counties need to rely on their consulting engineers to guide the process, and offer solutions that work for the project and the client.

For more than 21 years, our designers have provided roundabout engineering and consulting services to city, county, and state agencies. Reid Middleton can help all facets of roundabout design, from performing initial feasibility studies, traffic counts, to providing full PS&E and construction administration of the roundabout. The range of roundabout consulting and design services we provide includes:

  • Feasibility studies
  • Traffic counts/analysis
  • Roundabout PS&E
  • Peer review
  • Roundabout training
  • Public interaction/stakeholder involvement
  • Investigative support
  • Construction administration
  • Post-construction monitoring

021+ years providing roundabout consulting and design

0200+ roundabouts analyzed, designed, or peer-reviewed

09 states we’ve provided roundabout services

Granite Falls Alternate Route Roundabout

Granite Falls, WALearn More

Snohomish 15th & Avenue D Roundabout

Snohomish, WALearn More

Pioneer Highway & Fir Island Roundabout

Skagit County, WALearn More

While You’re Yielding to Traffic,
Let’s Share some Details


Reid Middleton has analyzed, designed or reviewed more than 180 roundabouts since 1995. During that time, we have strengthened our expertise about the mechanics and nuances of roundabouts. Roundabout design does not lend itself to a cookie-cutter approach, as guidelines and judgment govern process rather than standards. Roundabout design is not a linear process to be worked through with a series of checklists, but rather follows an iterative process by which to reach a final solution.

We are now considered leaders in roundabout design, and have provided roundabout services for cities, counties, and states across the U.S. In addition to performing analysis, feasibility studies, and geometric design, Reid Middleton provides full plans, specifications, and estimates (PS&E). After our roundabouts have been constructed, we validate our designs by analyzing traffic as it uses the working roundabout.

Is a Roundabout the Right Solution? Reid Middleton roundabout staff are adept at determining whether a particular intersection is a good candidate for a roundabout. Traffic analysis is done to help determine this, but many other factors will be considered too.

Roundabout Geometry: After initial design of the roundabout is created, the fastest and natural drive paths are analyzed. This shows deficiencies in entry and exit geometry, and will indicate where an increase or decrease of curvature should be introduced. We often see geometry that looks good in theory but will be negated in practice, as the vehicle will take a more direct route through the roundabout. A safe and efficient design dictates driver behavior in such a way that awkward driving conditions are avoided.

Plans, Specifications, & Estimates: After the groundwork of feasibility studies and geometry have been done, the plans, specifications, and estimates are prepared and finalized with the client.

Peer Review: Just as with other engineering designs, Reid Middleton reviews roundabout designs created by other design firms or municipal clients, with the overall goal of improving the intersection’s safety and performance. Our experience allows us to validate results and identify or correct any concerns. We provide objective insight from seasoned roundabout engineers.

Public Involvement & Education: We know stakeholders will accept a solution when they can see the project area and traffic safety needs are satisfied, and when the process used to reach this solution is fair and open. We strive to present the evidence for roundabouts and allow the public to reach their own conclusion. We lead open houses, provide roundabout literature to help explain and inform, provide videos/photos of working roundabouts, and even provide full-size mock-ups of the roundabout with buses, semitrucks, and cars. We regularly teach roundabout design classes to municipal agencies seeking to improve their roundabout design tools.