Airport Way South Viaduct Over Argo Railroad Yard Rehabilitation Project

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
ken.lee@seattle.gov

Maribel Cruz
Project Communications
(206) 684-7963
maribel.cruz@seattle.gov

Bob Derry
Community Communications Officer
(206) 250-2865
bob@stephersonassociates.com