BURIEN – Construction work is ramping up on the State Route 509 Completion Project in Burien, Des Moines, Kent and SeaTac.

The Washington State Department of Transportation is hosting an open house on Tuesday, Feb. 11, for people to learn more about the final stage of the completion project. This stage builds the remaining 2 miles of the tolled expressway between 24th Avenue South in SeaTac and South 188th Street, in addition to building new roundabouts at South 160th and South 188th streets in south King County.

SR 509 completion open house information

• When:       6 to 8 p.m. Tuesday, Feb. 11
• Where:     Burien Community Center
                    14700 Sixth Ave. SW
• Details:     People are invited to stop in at any time. There is no formal presentation planned. WSDOT and contractor staff will be available to answer questions about planned construction, anticipated closures, roundabouts, noise, multimodal improvements, environment processes and studies, traffic and the toll-rate setting process.

SR 509 Completion Project information

The SR 509 Completion Project builds 3 miles of new tolled expressway between Interstate 5 and South 188th Street near the south end of Seattle-Tacoma International Airport. The new expressway will be completed in stages. The first mile between I-5 and 24th Avenue is currently under construction and scheduled to open in fall 2025. The entire project is planned for completion by 2029.

Photos of construction work are available on the project’s Flickr page. An interactive project map that allows people to explore the new SR 509 Expressway, the SR 516 interchange and other elements of the completion project is also available online.  

Puget Sound Gateway Program overview

The SR 509 Completion Project is part of WSDOT’s Puget Sound Gateway Program, which also includes the SR 167 Completion Project in Pierce County. Combined, the two completion projects finish critical missing links in Washington’s highway and freight network.