Local Information

SR 509 Completion Project reaches a major milestone with $264 million apparent best value proposal

Wednesday, December 2, 2020 - 11:55

Laura Newborn, communications, 206-639-8577

Construction to start in early 2022 and end in 2025

OLYMPIA – After years of planning, the Puget Sound Gateway Program took a major step toward completing the State Route 509 corridor with the Washington State Department of Transportation’s selection of Guy F. Atkinson Construction as the apparent best value winner for the contract to build the next large phase of the project.   

The work, under the Puget Sound Gateway Program’s State Route 509 Completion Project includes:  

  • Building the first of 3 new miles of SR 509 Expressway
  • Constructing new freight connections from the Kent Valley to Interstate 5 and Sea-Tac International Airport
  • Creating additional access south of the airport to business centers in SeaTac and Des Moines

WSDOT announced that the $263,975,895 price proposal resulted in the “apparent best value” for this design-build project. A design-build contract combines final project design and construction into a single contract. The “apparent best value” determination is based on a combined score for the design proposal and project price.

“We’re building a large and complex project that includes a new highway and new connections to I-5, which is rare in an urban environment,” said John White, administrator of the Puget Sound Gateway Program. “Guy F, Atkinson Construction stood out for its creative ideas, accelerated construction schedule and commitment to minimizing disruption to the traveling public. We look forward to working with them.”

Key features of this stage of construction

The contractor will complete design work in 2021. Construction will start by early 2022 and is scheduled to wrap up by the end of 2025. The work includes:

Other construction stages of the SR 509 Completion Project

The first phase of the SR 509 Completion Project is underway and partners with Sound Transit to build a new SR 99 bridge as part of Sound Transit’s Federal Way Link Extension work. Combining these projects helps reduce the construction impact to nearby communities.

The final 2 miles of the new SR 509 Expressway between 24th Avenue South and 188th Street in SeaTac will be built under a separate contract, scheduled to be advertised in 2023 and completed in late 2028.

About the Puget Sound Gateway Program

The SR 509 Completion Project in King County and the SR 167 Completion Project in Pierce County are part of WSDOT’s Puget Sound Gateway Program.  Both projects are designed to complete essential connections to the ports of Tacoma and Seattle and ensure that people and goods move more reliably through the region.

The Puget Sound Gateway Program was authorized by the Washington State Legislature in 2015 and is funded with federal funds, local contributions, WSDOT’s Connecting Washington account and future toll revenues.

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