The modern roundabout has been successfully used as an alternative to signalized and stop controlled intersections throughout Europe, Australia, and most recently the United States. They are effective in controlling speeds, reducing vehicle conflict points, allowing for greater capacity, enhancing pedestrian and bicycle circulation, providing gateway entries, and most importantly, reducing the number of accidents. Modern roundabout intersections are another traffic control tool for planners and engineers to assess when designing streets, highways, and interstate facilities.

Parametrix staff are recognized leaders in the planning and design of modern roundabout intersections. Our professional staff paved the way in 1998 by designing and opening the first modern roundabout on a Washington State highway facility, SR 166/Bethel Avenue in Port Orchard, and then opened the first multi-lane roundabouts on Marvin Road in Lacey. Since then, Parametrix has been engaged with local communities, cities, and counties in the planning, design, and construction of modern roundabouts throughout the western United States.

Roundabout Evolution Table

Roundabout Experience Table

Our services:

Project Examples

Training/Seminars

Parametrix also offers seminars on a range of roundabout topics. These seminars range from one day to three days depending on client's interest and needs. For more information visit our roundabouts training page.