SR 202 Woodinville Roundabouts
Location: Woodinville, Washington
The intersection of SR 202 and 145th Avenue NE had been operating at a poor level of service for years. For more than six years, city consultants were unable to implement a proposed roundabout solution that addressed all major concerns. In 2005 an innovative mixed-use development proposal created an opportunity to address the city’s traffic challenges and the access needs of the new development project with a comprehensive solution.
The DEA team proposed a unique three-roundabout system that would provide U-turn opportunities for adjacent businesses and their customers while also producing a calming effect on approaching high-speed traffic. The resulting system included two external, single-lane roundabouts that offered speed control for approaching vehicles, as well as access and U-turn capabilities to the new development. The proposal of a three-roundabout system addressed Washington State Department of Transportation's previously expressed safety standard concerns and also incorporated stakeholder property access needs. Traffic analysis, using aaSIDRA, was completed to demonstrate that the three closely spaced roundabouts would operate for both AM and PM conditions through the year 2030.