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Airport Way South Viaduct Over Argo Railroad Yard Rehabilitation Project

January 4, 2013

Overnight lane closures on Airport Way South Bridge
Crews to install fencing Jan 7-11 and 14-18

Crews installing pedestrian fencing along the Airport Way South Bridge must intermittently close the outside lanes of the bridge for up to two weeks.  The work will be done each night from Jan. 7 to 11 and Jan. 14 to18, between 7 p.m. and 5 a.m. each night, ending at 5 a.m. each Friday. 

The SDOT project to rehabilitate the Airport Way South Bridge reached substantial completion December 21, and the bridge opened up to traffic. Following a manufacturing delay, this final project element can now be completed.

December 18, 2012

Click for largerJoin the Seattle Department of Transportation (SDOT) to celebrate the completion and grand re-opening of the Airport Way South Viaduct!

Come help us celebrate and:

  • Hear from the Mayor, City Staff and the Community who helped make this project happen.
  • Shake hands with the contractor.
  • Join your neighbors for an inaugural cutting of the ribbon.

The event will be held this Friday, December 21, 2012 at 3:30 p.m. at the south approach to the viaduct near Airport Way S and S Lucile Street.


October 29, 2012

See the previous updates page for past progress.

We can see the light at the end of the tunnel or perhaps it’s across the bridge! Continuous progress is being made towards completion of the Airport Way South Viaduct (AWSV).  The bridge is expected to open to traffic by the end of the year.
Highlights of work currently underway are:

  • The Structural Earth Wall Approaches are currently being finished on the south while the completed north approach is being utilized for setting the precast concrete girders.
  • After the precast girder setting is complete, the concrete bridge deck will be poured.
  • The main span steel structure rehabilitation, which is a major milestone, has been complete! This includes the installation of floor beams and through girder stiffeners.
  • The existing concrete column rehabilitation is also complete.  All of the concrete spalls are fixed and columns have been sealed with a protective sealant. 
  • Various drainage work is ongoing.  Paving will be scheduled in and around the project site, once the drainage work is complete.

Photo ‘Columns’ Description- View of the rehabilitated mainspan columns.  After spall repairs and an application of a concrete sealant, they look brand-new!

Photo ‘Precast Concrete Girders’ Description- The precast girders are being set on the mainspan by the Contractor’s crane which is mobilized on the mainspan. 

Photo ‘N Approach’ Description- View of the South Approach, looking north.  Progress is being made on the approaches by utilizing heavy equipment- transporting and properly compacting the Structural Earth fill.

Photo ‘Wall.’ Description- View of the west side of the south approach.  You really get a sense of how large the volume of fill, the approach really contains!

Detour Information:

  • Southbound vehicles & pedestrians will be detoured at South Industrial Way to 4th Avenue South, returning to Airport Way South via South Lucile Street.
  • Southbound cyclists will be detoured at South Lander Street to 1st Avenue South returning to Airport Way South via South Lucile Street.
  • Northbound vehicles & pedestrians will be detoured at South Lucile Street to 4th Avenue South, returning to Airport Way South via South Industrial Way.
  • Northbound cyclists will be detoured at South Lucile Street to 1st Avenue South returning to Airport Way South via South Lander Street.
  • Denver Avenue South and South Dawson Street between South Lucile Street and 4th Avenue South will be used primarily as a northbound truck detour route
  • Signage will be placed throughout the region to alert users of the viaduct closure and detour routes.

A map of the detour route can be found here.

Bus routes that currently use the Airport Way South Viaduct will be rerouted to 4th Avenue South during the closure. Transit agencies will communicate any route changes to customers directly.


Project Description

Airport Way South is a heavily traveled arterial, important to businesses, freight operations, the Port of Seattle, commuters, cyclist, and residents of Georgetown and the surrounding area. The Airport Way South Viaduct was originally built in 1928 to provide grade separation between Airport Way South and the Union Pacific, Northern Pacific and Seattle to Tacoma Interurban railroad tracks.

With over 13,000 vehicles traveling on Airport Way South daily, the structure has experienced increased stress over time. SDOT is on schedule to replace the north and south approaches of the Airport Way South Viaduct as part of the City’s Bridging the Gap program. The work will include seismic retrofitting and rehabilitation of the mainspan of the viaduct. Completing this project is necessary to maintain a safe and reliable transportation corridor for vehicles, pedestrians, and bicycles. The estimated total project cost of the project is $34 million. During construction the viaduct will be closed for approximately 12 – 14 months.

Construction Detour

During the viaduct closure, all vehicles will be detoured to 4th Avenue South. Bicycles and pedestrians will be detoured to 1st Avenue South. Signage will be placed throughout the region to alert users of the viaduct closure and detour route.

Project Improvements

  • Replacement of the existing north and south timber-framed approach structures with a mechanically stabilized earth (MSE) wall structure.
  • Rehabilitation and seismic improvements to the mainspan of the viaduct.
  • Ground improvements to address poor soil conditions at the approaches.
  • A new driving surface on the mainspan of the bridge and improvements to surrounding Georgetown Streets.
  • Prior to the start of construction, improvements were made to South Lucile Street, South Dawson Street, Denver Avenue South and Airport Way South.

Project Benefits

Improves safety

  • Creates a stronger, more durable structure to serve current and future traffic conditions.

Keeps freight moving

  • A stronger structure improves the load-carrying capacity of this vital link.
  • A more durable concrete deck and approaches will significantly reduce the frequency of major repairs and associated traffic disruptions.

Protects an important asset

  • Extends the structure’s useful life by decades.

Reduces the City’s maintenance backlog

  • Contributes to the improvement of Seattle’s transportation system, and reduces maintenance requirements.

Environmental Considerations

Following a thorough environmental review, SDOT determined that the Airport Way South Viaduct Over Argo Railroad Yard Rehabilitation Project is not likely to result in significant adverse impacts to the environment. As a result, SDOT issued a Determination of Non-significance (DNS) on October 25, 2010. This decision was made after review of the project's potential impacts on several elements of the environment, summarized in the SEPA environmental checklist.

Aesthetic Improvements

Upon completion of the project, the structure will have a new light pole, a pedestrian railing, and a wall designed with the historical character of the neighborhood in mind.

Project Funding

The project is part of the City of Seattle’s Bridging the Gap program, and will cost approximately $34 million. Bridging the Gap is a $365 million levy passed by Seattle voters in 2006 that enables much-needed maintenance and improvement work by SDOT, such as roadway paving, sidewalk development and repair, bridge maintenance, and tree pruning and planting. It also supports enhanced transit connections and the City of Seattle’s Large Neighborhood Street Fund Projects.

Only In Seattle Campaign

The City of Seattle is committed to supporting local Georgetown businesses during construction. In November 2010, the Office of Economic Development launched the Only in Seattle Campaign, with Georgetown as one of the featured business districts. Visit Only in Seattle to learn more.

Project Materials

Project Fact Sheet – Winter 2011

Drop-in Session Materials and comment form – November 2010

Frequently Asked Questions (FAQ) – November 2010

60% Design Open House materials – July 2010

30% Design Open House materials – January 2010

Want to Learn More?
For the latest news and information, contact:

Ken Lee
Project Manager
(206) 684-3514

Maribel Cruz
Project Communications
(206) 684-7963

Bob Derry
Community Communications Officer
(206) 250-2865

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