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South Spokane Street Project

Revised Dec 5, 2012

Spokane Street Viaduct Widening Project Has Been Completed

After some three and a half years of construction, completion of the Spokane Street Viaduct Widening Project was celebrated with a ceremonial ribbon cutting on Friday, November 16.  A group of elected officials and community leaders made brief comments before joining together for the ribbon cutting, followed with cake and coffee.

Behind Mayor Mike McGinn left to right, Councilmember Tom Rasmussen, Port of Seattle Commissioner Bill Bryant, Seattle Arts Commission Chairperson Jon Rosen, Washington State Department of Transportation official Linea Laird, West Seattle Chamber of Commerce President Dave Montoure, and partially hidden SDOT Director Peter Hahn

Left to right, Councilmember Tom Rasmussen, Port Commissioner Bill Bryant, Mayor Mike McGinn, Peter Hahn, West Seattle Chamber President Dave Montoure, and viaduct column artists Claudia Reisenberger and Franka Diehnett

The project has doubled the viaduct width, adding 41 feet via a new structure built immediately adjacent to the old structure, which itself was refurbished and seismically reinforced.  The additional width allowed the project to install wider travel lanes, and add shoulders and deceleration and merge lanes, creating a safer and smoother traffic flow.  The project also added a new eastbound off-ramp at Fourth Avenue S, which opened to motorists in the summer of 2010.  The lower Spokane Street was fully reconstructed in concrete, including a standard sidewalk on the south side and multi-use trail on the north side of the street that connects seamlessly with the existing bike path west of East Marginal Way.  Finally, the project’s artwork enlivens the area below the viaduct with color and image schemes that recollect the natural and cultural history of the location.

The City of Seattle and the Seattle Department of Transportation (SDOT) would like to thank those who live and/or work in West Seattle or SODO for their cooperation, patience and understanding during construction. 

Nearing Completion

After some three years of construction, the Spokane Street Viaduct Widening Project, is nearing completion.  It is now expected that the project will largely be finished in October, with only small items remaining to be completed.  (Before the project is officially finished, the City of Seattle will evaluate the performance of the contractor to ensure that the work has been delivered as specified in the contract.  As is customary on such major projects, it is likely the contractor will be directed to make adjustments to some of the work they have performed.)

The long awaited combination westbound on/off-ramp at First Avenue S in SODO opened to motorists on the morning of Friday, August 31, just in advance of the Labor Day Weekend.  (West Seattle commuters from SODO no longer need to detour across the surface Spokane Street Swing Bridge!)  The ramp includes a deceleration and merge lane, making it safer for motorists either exiting or entering the flow of viaduct traffic. 

Construction crews have also completed work to repair and resurface the bridge deck on the old viaduct structure.  As the accompanying photo shows, much of the existing deck was in need of considerable repair, which began with “scarification” or “hydro demolition” which cleaned and roughened the deck in order to ensure a good bond when the new thin lift micro silica overlay was applied.  In those areas where a loss of more than 20% of the existing rebar, the rebar was replaced. 


The repair and resurfacing work on the old bridge deck had to be broken into phases in order to keep the structure open to traffic (with closures limited to nighttime and an occasional weekend).  For much of the time, the eastbound off-ramp to First Avenue S had to be closed, although the off-ramp at Fourth Avenue remained open.  (For shorter periods, it was the First Avenue exit that remained open while the exit at Fourth Avenue had to be closed.) 

Work on both the old and new bridge decks is essentially complete at this time.  The final lane configurations have been painted into the roadway and motorists have been using them for a number of weeks.  The posted construction speed limit of 25 MPH will be reposted to the previous preconstruction 35 MPH (if it has not already been done by the time you are reading this post).  SDOT traffic engineers intend to reexamine the speed limit this coming spring after motorists have adjusted to the lane configuration and engineers are better able to assess the proper speed limit. 

Artwork has been installed on many of the supporting columns underneath the viaduct.  Some have historical themes, while others are more abstract.  Once the artwork has been fully installed and the contractor has completed their work, the westbound lower roadway will reopen all the way from Sixth Avenue S to East Marginal Way S.  This is currently projected for early October.  (The westbound surface roadway reopened to traffic in 2010.) 

The eastbound Fourth Avenue S off-ramp was opened to traffic in the summer of 2010, permitting motorists and freight direct access to both north and southbound Fourth Avenue S while avoiding rail crossings.  Ramp construction was made possible in part through $25 million in funding the Washington State Department of Transportation (WSDOT), who view the off-ramp as a valuable alternative route for West Seattle traffic heading to downtown or SODO while the Alaskan Way Viaduct Replacement Project is under construction. 

Key Schedule Dates


Closure or milestone

February 2009

Project construction begins with work on the new eastbound Fourth Avenue S loop off-ramp

January 2010

Close and remove existing westbound off-ramp from westbound S Spokane Street Viaduct to Fourth Avenue S

January 2010

Close westbound surface S Spokane Street (lower roadway) between Sixth Avenue S and Fourth Avenue S, then to East Marginal Way by February 1

May 17, 2010

Close and remove existing on-ramp to westbound S Spokane Street Viaduct from First Avenue S

Summer 2010

Open eastbound S Spokane Street lower roadway

August 16, 2010

Open new eastbound Fourth Avenue S loop off-ramp

August 31, 2012

Opened new westbound S Spokane Street on/off-ramp at First Avenue S. 

November, 2012 Project Substantially Complete

* all future dates subject to change due to unforeseen circumstances

Project Description

The Seattle Department of Transportation (SDOT) is widening and improving the South Spokane Street Viaduct – the 60-year old elevated roadway that carries 65,000-70,000 vehicles daily between I-5 and the West Seattle Bridge. The South Spokane Street project created a new two-lane eastbound off-ramp leading to Fourth Avenue S; relocates the westbound on- and off- ramps to a new First Avenue S ramp; widens the upper roadway to the north by 41 feet – between Sixth Avenue S and East Marginal Way; and rebuilds the lower roadway in concrete, with new curbs, sidewalks and improved pedestrian and bicycle access. Work on this long-awaited project began in 2008 and is set to wrap up in the summer of 2012.

Click here to view larger version of Project Overview Map

Widening of Spokane Viaduct (Upper Roadway)

The upper roadway between 6th Avenue South and East Marginal Way is being widened to the north by 41 feet.

The existing upper roadway deck will be repaved and variable message signs will be installed.

Seismic strengthening of the viaduct will be completed.

The widened structure will allow room for:

  • Two thru lanes of traffic in each direction
  • A new westbound acceleration/ deceleration lane
  • A permanent median
  • Wider lanes and shoulders
New Eastbound 4th Avenue Off-Ramp

A new eastbound, two-lane off-ramp to the Spokane Street upper roadway opened in August, 2010. The ramp touches down at 4th Avenue South, where vehicles may head either northbound or southbound on 4th Avenue South.

The new ramp provides eastbound travelers on the West Seattle Bridge with direct access to downtown Seattle via 4th Avenue South.

This new exit allows traffic to exit the viaduct east of the rail tracks and thus avoid surface congestion due to rail-caused delays for vehicles.

In addition, whenever the upper roadway becomes congested due to back-ups onto I-5, the new ramp allows drivers to exit onto surface streets.

New Westbound On- and Off-Ramp at 1st Avenue

The now demolished westbound off-ramp at 4th Avenue South is being replaced by a new ramp at 1st Avenue South, built to current design standards.

The old westbound 1st Ave. on-ramp was closed and demolished to make room for the widened upper roadway.
Relocating the westbound ramps to 1st Avenue South will improve westbound traffic flow and safety. (The old ramps at 4th Avenue South required an abrupt weave from the I-5 merge to exit off the viaduct, and a sharp right turn to enter traffic westbound. The new westbound merge lanes at 1st Avenue South will allow for smoother and much safer entry to and exit from the upper roadway.)
South Spokane Street Reconstruction (lower roadway)
The lower roadway is being rebuilt with curbs and gutters, and a new 10-foot wide sidewalk, with landscaping installed along the north side of the lower roadway. The eastbound lower roadway reopened in the summer of 2010 while the westbound lower roadway will reopen in the summer of 2012. Improvements to the lower roadway will create safer travel options for pedestrians and cyclists, as well as for transit, freight and the motoring public. The work will also beautify the area; improve drainage and result in a longer-lasting roadway.

Staying Informed

Listserve notices: We distribute email announcements for impending lane changes or closures, detours, schedules, etc. as well as periodic information about progress on the project. Use the form below to be added to that email list.

Progress Bulletins: We periodically create and hand-deliver to surrounding properties, providing information about recent progress, upcoming activities, expected impacts and mitigation measures. These are also available at the SDOT office, on this Web site and through the listserve. We also occasionally print and mail newsletters to businesses and residences in a large area with general project information, schedule updates and contact information. These are also made available to community groups, libraries and other distribution venues, as well as in our offices. If you have a suggestion for a valuable distribution point, please let us know.

Web site updates: Information on the project is maintained here.

Project Update Briefings: We provide periodic in-person updates to identify project stakeholders, such as West Seattle and Georgetown neighborhood organizations, the Seattle Freight Advisory Board, the Manufacturing and Industrial Council (MIC), SODO Business Association and others. Contact us to find out about joining a group for a presentation, or having a presentation for your organization.

Alternative modes of communication: We are looking at other means of providing information on the current status of the project and on upcoming activities, including text messages and low power AM radio broadcasts. We are also posting project update stories to our Blog. If you have other suggestions on outreach methods, please let us know. We are committed to working with local community and business organizations to provide communications that meet their constituents’ needs.

If you need this information translated, please call (206) 733-9990.

Si necesita traducir esta información al español, llame al (206) 733-9990.

Kung kailangan mo ang impormasyon na ito na nakasalin sa Tagalog, mangyari lamang na tumawag sa (206) 733-9990.

Haddii aad u baahan tahay warbixintan oo Soomaali ku turjuman, fadlan la hadal (206) 733-9990.

Nếu quý vị cần thông tin này chuyển ngữ sang tiếng Việt, xin gọi (206)733-9990.

If you would like more information about the project, please call or email Paul Elliott, SDOT Community Relations, at 206-684-5321 or by email at

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