A portion of the $2.68-billion Puget Sound Gateway Program takes another step forward with the announcement by the state transportation department of the design-build team to lead the State Route 509 Stage 2 Completion Project.

That $478.8-million portion will be led by Guy F. Atkinson Construction as the contractor and Jacobs as the designer. The work includes five new bridges, one bridge modification, stormwater conveyance and treatment facilities and construction of transportation infrastructure.

Jacobs and Atkinson continue a "strong collaboration" in their work for the Washington State Dept. of Transportation, Katus Watson, Jacobs senior vice president, said in a statement.

Jacobs and Atkinson have already been part of the larger Puget Sound Gateway Program that combines work on the SR 509 Completion Project in King County with the SR 167 Completion Project in Pierce County. That work will complete “critical missing links in Washington state’s highway and freight network,” WSDOT says.


The $2.68-billion Puget Sound Gateway program aims to improve movement of freight to the state's ports while also reducing congestion on local roads and highways.
Map courtesy Washington State Dept. of Transportation

The projects all aim to build new connections to the state’s ports to improve movement for freight and reduce congestion on local roads and highways. The larger project started in 2015 and is scheduled to wrap in 2029. The SR 509 portion already completed Stage 1a, which included a Sound Transit project to build a bridge over SR 509 in SeaTac as part of the agency’s Federal Way Link Extension light rail project.

The Stage 1B project—in progress and also led by Atkinson—includes the first mile of a new SR 509 expressway between Interstate 5 and 24th Avenue South in SeaTac. Scheduled for a 2025 completion, the project includes new interchanges, ramps and street overpasses.

The Phase 2 project—the final portion of the SR 509 Completion Project—builds the remaining two miles of the expressway linking the entire SR 509 corridor to I-5. The work will add a southbound auxiliary lane on I-5 between SR 516 and South 272nd Street. Design work is ongoing, and construction is scheduled to start in late 2024 or early 2025 and wrap up in 2028.