Washington 99

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Washington 99 follows a portion of old U.S. 99 through the Seattle-Tacoma area, beginning at Interstate 5 in Fife and leading north 49 miles to Interstate 5 at Everett. There is a gap in the alignment from SR 518 by Seattle Tacoma International Airport in SeaTac and the Washington 599 (Marginal Way) freeway in Tukwila.

Marginal Way carries SR 99 northward through the industrial south side of Seattle along a road that varies with freeway and at-grade sections. This route takes Washington 99 northward onto the Alaskan Way Viaduct, an elevated roadway with double deck sections leading north to Downtown by the Puget Sound waterfront to a tunnel at 1st Avenue.

Constructed in 1952, the tunnel portion of SR 99 under Belltown leads the state route northward to Aurora Avenue. Aurora Avenue comprises a multi-lane boulevard northward to Westlake, Woodland Park, Northwest Seattle and an exit of the city into Shoreline.

A major project broke ground on October 21, 20111 to address structural concerns with the aging Alaskan Way Viaduct. The elevated roadway, completed on April 4, 19531, was in need of replacement, but how to go about it was the question debated for several years after the February 2001, 6.8 magnitude earthquake that hit Seattle. The solution was the $4.25-billion project1 to construct a two-mile long tunnel below downtown Seattle linked by a new one mile highway from the south entrance of the new tunnel by the stadiums. This subterranean route will bypass the existing tunnel below Belltown.

Boring for the new tunnel commences in summer 2013 and will continue until late 2014. Completion of the tunnel is expected in late 2015. It replaces the Alaskan Way Viaduct, which is partially demolished as of summer 2013 within the vicinity of the stadiums and south of King Street. Replacing the concrete structure will be a new Alaskan Way surface street along the waterfront to connect Washington 99 with downtown. Demolition of the remaining viaduct will take place in 2016 along with construction of the new surface boulevard.2

Washington 99 Highway Guides

This view looks at Washington 99 and the end of the double decked portion of the Alaskan Way Viaduct. The freeway approaches the Western Avenue off-ramp and Battery Street Tunnel beyond the curve here. Photo taken 08/28/06.

Taken from the same perch at Victor Steinbruek Park is this view of Washington 99 (Alaskan Way Viaduct) south. Qwest Field illuminates the horizon. Photo taken 08/28/06.

Pike Street passes under the Alaskan Way Viaduct from Alaskan Way as a pedestrian walkway in this scene of the Washington 99 double deck freeway in downtown Seattle. Photo taken 08/28/06.

Yesler Way passes under the Alaskan Way Viaduct from Washington 99 and the WSDOT Seattle Ferry Terminal. Photo taken 08/30/06.

Washington 99 and the Alaskan Way Viaduct rise behind Alaskan Way in this scene looking east from Waterfront Park. Photo taken 08/28/06.

Curving southwest near Royal Brougham Way are Alaskan Way and the Alaskan Way Viaduct (Washington 99). This scene changed dramatically in October 2011 when the elevated roadway was demolished. A temporary bypass was added to the east, keeping SR 99 in service, with a permanent connection to the new SR 99 tunnel slated for completion in late 2015. Photo taken 08/30/06.

Washington 99 scenes
East Marginal Way South parallels Washington 99 below the Alaskan Way Viaduct through the West Seattle Bridge interchange. Spokane Street follows the elevated West Seattle Bridge at the surface and intersects East Marginal Way in this scene. Photo taken 08/30/06.
East Marginal Way carries two-way traffic along the west side of the Alaskan Way Viaduct and northbound traffic only on the east side to Hanford Street. This view looks at East Marginal Way south near its merge with Washington 99 at the viaduct end. Photo taken 08/30/06.


  1. Alaskan Way Viaduct @ Wikipedia.org.
  2. Alaskan Way Viaduct Replacement Program (WSDOT)

Photo Credits:

08/30/06 by AARoads

Connect with:
Interstate 5
Washington 519
Washington 525

Page Updated 06-13-2013.