The three linked roundabouts Tumwater opened in 2024 at Capitol Boulevard SE and Trosper Road SW cost $20 million.

That price tag bought more than smoother traffic. It prevented the city from having to scale back its signature commercial corridor redevelopment plan.

A five-part investigative series published June 14 by The JOLT News examines how the project, formally called the Capitol Boulevard and Trosper Road Intersection Reconfiguration, grew out of a state law that ties new development to road capacity.

Under the Washington State Growth Management Act's "concurrency" rules, municipalities must expand highway capacity to match current and projected growth before new development can proceed.

For Tumwater, that meant a choice JOLT reporter Ted Wham described as "impossible": spend $20 million to increase capacity at the city's busiest intersection, or significantly scale back the Capitol Boulevard Corridor Improvement Plan, a redevelopment blueprint adopted in 2014, covering the stretch of Capitol Boulevard between the Southgate shopping center and Israel Road.

The city committed to the project.

The Capitol Boulevard Corridor Plan targets Tumwater's primary commercial spine with three goals: improving the business climate, expanding transportation options for pedestrians, cyclists, and drivers, and upgrading the corridor's appearance. The city developed it with the Thurston Regional Planning Council and consultant team MAKERs Architecture and Urban Design.

The plan remains an active priority. Tumwater's current strategic plan lists "Implement Capitol Boulevard Corridor Plan" as a live action item, with two sub-tasks: acquiring the former WSDOT headquarters site on Capitol Boulevard and completing right-of-way work for the next roundabout at Capitol Boulevard and X Street.

That fourth roundabout is estimated at $6.8 million, including $2.8 million for right-of-way acquisitions. The city has secured five federal grants totaling $5.4 million through the Thurston Regional Planning Council.

As of November 2025, construction was targeted for summer 2026. Whether that timeline held could not be independently confirmed at publication.

Tumwater Transportation and Engineering Director Brandon Hicks presented the project to the Public Works Committee on November 20. At least one property, a heating and cooling company building at the corner, would have to be demolished entirely. A roofing business on another corner would lose its front parking lot.

"The one property being a full take — it could be difficult," Hicks told the committee. "Hopefully we can obtain them all just through standard negotiations."

Beyond roundabouts, the city is eyeing the vacant 12-acre former WSDOT Olympic Region headquarters on Capitol Boulevard for mixed-use redevelopment. Community Development Director Michael Matlock told the city council in April 2024 that the vision splits the site into thirds: affordable housing, market-rate housing, and commercial space.

As of that briefing, environmental assessment work was underway, funded by a $200,000 state Department of Ecology grant and a $500,000 EPA grant approved by the council in March 2024. The city's current strategic plan still lists the site acquisition as active.

The JOLT series is the first of five planned installments examining how concurrency requirements shape development across Thurston County's eight urban regions.