Search projects

The SR 509 Completion Project in King County is part of the Puget Sound Gateway Program, which also includes the SR 167 Completion Project in Pierce County. Together, these projects complete two of the Puget Sound region’s most critical freight corridors and improve access to I-5, the ports of…

Reconnecting waterways where our roads act as barriers is a priority for the state. In western Washington, that means building hundreds of fish passable structures under state highways to create habitat essential for meeting fish recovery goals.

A culvert below State Route 509 west…

In 2021, contractor crews working for WSDOT replaced the more than 20-year-old worn grid deck on the Montlake Bridge. They also made expansion joint and mechanical repairs so the movable span can continue to operate reliably and meet the growing multimodal traffic demands of northeast Seattle. In…

Prior to construction, which ended in October 2023, a failing clay culvert just 2 feet in diameter carried Barnes Creek under SR 516 near Des Moines. This narrow culvert was a barrier for fish trying to swim upstream. This project replaced that small clay culvert with a new cement box culvert 20…

During summer 2023, our contractor crews replaced the damaged girder on the 24th Avenue South bridge over SR 518 near the Sea-Tac International Airport. Crews also made bridge drain and drainpipe improvements in the area.

Crews working for WSDOT applied spray sealant to the bridge deck and soffits near expansion joints in both directions of the State Route 520 Evergreen Point floating bridge. The sealant will protect the bridge from corrosion, prolong its service life and help keep the bridge in a state of good…

With this Connecting Washington project, we made multiple improvements to the State Route 520/148th Avenue Northeast interchange within the cities of Bellevue and Redmond.

Our contractor, Granite Construction, built a direct-access off-ramp from eastbound SR 520 to the Overlake…

This project added bus/carpool lanes in both directions between 108th Avenue Northeast in Bellevue and Lake Washington’s eastern shore. The project also built three landscaped, community-connecting highway lids over the highway, two transit stations in the highway median and the first leg of a…

We replaced the world's longest floating bridge – a four-lane, 1960s-era structure – with a safer, six-lane bridge designed to withstand stronger windstorms and waves. Opened in April 2016, the new bridge also added shoulders for disabled vehicles and a separated, 14-foot-wide path for…

The SR 520/I-5 Express Lanes Connection Project will create a dedicated reversible transit and carpool connection between SR 520 and the I-5 Express Lanes, along with a reversible transit/carpool ramp at the I-5/Mercer Street interchange.

The Montlake Project will improve transportation for both motorized and nonmotorized travel along the corridor with a new SR 520 eastbound bridge over Union Bay. This project also builds a new, three-acre lid covering the highway in Montlake that will include regional transit stops and open green…

The SR 520 floating bridge is supported and stabilized by 77 concrete pontoons . The Pontoon Construction Project built a casting basin and 33 of the bridge’s pontoons in Aberdeen, Washington. We built 44 of the bridge’s smaller pontoons in Tacoma, Washington, as part of the Floating Bridge and…

The Portage Bay Bridge and Roanoke Lid Project will replace the aging Portage Bay Bridge with a seismically resilient structure that includes improved bus/carpool travel and an extension of the SR 520 Trail. This project also builds a landscaped lid between Seattle’s Roanoke Park and North Capitol…

The West Approach Bridge North Project extended SR 520’s three westbound lanes, including a transit/HOV lane, from the new floating bridge to Seattle’s Montlake neighborhood. It also expanded the new SR 520 Trail across Lake Washington to Seattle.

Currently, over half the trips from westbound SR 520 are traveling to the Bellevue vicinity. A new project will allow westbound drivers the option to access the downtown Bellevue vicinity by exiting SR 520 onto 124th Avenue Northeast before reaching the heavily congested I-405/SR 520 interchange.…

WSDOT contractor crews will repave sections of SR 522, commonly known as Lake City Way or Northeast Bothell Way, which were last paved in 2002.

Reconnecting waterways where roads act as barriers is a priority for the state. In western Washington, this means building hundreds of fish-passable structures under state highways to create habitat that is essential for meeting fish recovery goals.

A culvert below State Route 522…

This project will replace the State Route 525 bridge overcrossing the BNSF railroad in the city of Mukilteo. The new bridge will include active transportation improvements to improve safety for all travelers and increase connectivity between Old Town Mukilteo and the waterfront, including the new…

Reconnecting waterways where our roads act as barriers is a priority for the state. In western Washington, that means building hundreds of fish passable structures under state highways to create habitat essential for meeting fish recovery goals. Beginning as early as winter 2024, WSDOT will install…

State Route 900/Martin Luther King Jr. Way South in the unincorporated Skyway-West Hill community is a busy roadway between Renton and Seattle serving drivers, freight, public transit, bicyclists and pedestrians. This project will construct bicycle and pedestrian facilities on SR 900 that allow…

In the Bryn Mawr-Skyway area of King County between Seattle and Renton, just west of 68th Avenue South, we worked with King County Metro to build 500 feet of new sidewalk and a raised platform for pedestrians to access a Metro bus stop on the east side of the highway.

This new…

Part of a culvert running underneath the State Route 99 on-ramp to eastbound SR 518 in Tukwila failed, damaging the on-ramp as well as the shoulder along the Airport Expressway on-ramp to eastbound SR 518.

Contractor crews repaired failed section of the culvert to prevent further…

The SR 99 tunnel replaced the Alaskan Way Viaduct along Seattle's central waterfront, carrying State Route 99 beneath downtown Seattle. The 2-mile tunnel opened to drivers in February 2019.

This project will replace watertight doors, demolish the East Control Tower’s top two floors and seal the new roof on the northbound State Route 99 1st Avenue South Bridge from mileposts 26.83 to 26.88. This project will also include waterproof membrane roof work on the West Bridge Control Tower…

This project will resurface the northbound and southbound lanes of State Route 99 from South 272nd Street to SR 516 to extend the pavement service life. Crews will grind and inlay new Hot Mix Asphalt (HMA), perform pavement repair, traffic loop replacement, striping and traffic control. Pedestrian…

Contractors working on behalf of WSDOT will replace 13 expansion joints on the State Route 99 Spokane Street Bridge and rehabilitate the bridge’s drainage system. This work will help preserve the service life of the bridge.

Crews working for WSDOT will texture the existing concrete pavement of the north and southbound State Route 99 tunnel. The technique of shot-blasting the roadway will provide added friction for vehicles’ tires and improve traction.

This project will rehabilitate nearly two miles of State Route 99 from the SR 516 intersection in Des Moines/Kent to South 200th Street in SeaTac. Crews will grind away existing asphalt and install new hot mix asphalt, giving the roadway a smoother surface and extending its lifespan. Pedestrian…

In 2020 and 2021, contractor crews will repair the bridge decks on nearly two dozen structures along US 2 between the area west of Index (Proctor Creek/Big Bend) and Skykomish (Tye River vicinity).

In fall 2023, we built two debris flow fences on the north side of US 2 near milepost 44, or approximately four miles northwest of Skykomish. These fences will help mitigate risk to two culvert inlets, reducing the chances a potential debris flow from the Bolt Creek burn scar could clog them and…