The Ten Bridges of the Spokane Street Corridor

Did you know that the Spokane Street corridor is made up of ten – yes ten – bridges!  Why so many bridges? 

 Some of the earliest pictures of Seattle from the 1880’s, show the Spokane Street corridor.  Initially there was a series of wood trestles that stretched from the shoreline at the base of Beacon Hill to the shoreline below West Seattle, across the tide flats.  This was long before the SODO area was filled.  Spanning across the Duwamish River and maintaining navigation on the river required a movable bridge at this location.  Over the years, the SODO area was filled and Harbor Island was also created by filling.  Major rail yards and the associated tracks were constructed crossing the Spokane Street corridor.  As Seattle grew as a city, West Seattle, with its spectacular views, became a popular place to live.  With over 150,000 vehicles using the corridor each day, the Spokane Street corridor is the most traveled roadway in the city (outside of I-5).  Over time, the combination of marine vessels, trains and vehicle required significant traffic management solutions. 

To separate vehicles from trains, the Spokane Street Viaduct was constructed in 1943.  This provided a grade separated roadway for vehicles to get from Airport Way to East Marginal.  There still was a need to cross the Duwamish River, which due to the addition of Harbor Island, actually consisted of two forks of the river, the East Waterway and the West Waterway.  Each of those two waterways required a bridge.  The West Waterway was chosen to be the shipping channel and dredging provided for deep draft vessel passage.  The first draw bridge at this location was built by King County in 1902.  When West Seattle was annexed to the City in 1907 a new draw bridge was built. 

This bridge proved to be too low to the water and required many opening for vessel traffic which in turn disrupted vehicle traffic.  The City then built a higher “swing” type bridge that opened in 1917.  This bridge was still considered temporary due to its timber construction.  In 1924 the first permanent “steel” draw bridge was opened to traffic.  A second draw bridge of similar design was completed in 1930.  This provided enough traffic lanes to handle street cars, vehicles and pedestrians.  The first steel bascule bridge was hit by a freighter in 1976 and was so seriously damaged that it was permanently closed. The City had already started a study to build a bridge that was high enough that vessels could pass underneath the bridge without requiring a disruptive bridge opening.  This turn of events resulted in the West Seattle High-level bridge. 

The high-level bridge provided good access to West Seattle, but it did little to provide access to the areas on Harbor Island and other nearby Port facilities.  Thus, the Spokane Street (low-level) Swing Bridge was built in 1991.  The steel mill was an early industry in Seattle.  Located on the West Seattle side of the Duwamish River, it required access to port facility and rail.  Bridges were built, five in all, to allow vehicles to cross the steel mill access.  Three bridges provided access to Harbor Ave and Avalon Way, two bridge provided access to Admiral Way.  In the 1949 earthquake,  one of the bridges was severely damaged and never rebuilt.  Four bridges exist today.  All were rebuilt in the late 1990’s.  Finally, as we move to the west, it was always difficult for vehicles to leave the low lands along the Duwamish River and climb the bluff onto the top of West Seattle.  Admiral Way was cut into the hillside and traversed up to the south end of California Way.  The construction of the Fauntleroy Expressway in 1963 provided a route to California Way that connected at the popular “junction” area of West Seattle.

So there are three separate sections of the Spokane Street corridor which actually consist of the following bridges, going east to west:

  1. I-5 bridges, from Beacon Hill (Columbian Way) onto the Spokane Street Viaduct
  2. The Spokane Street Viaduct (currently being widened)
  3. The West Seattle High-level Bridge, now officially called the Jeanette Williams Memorial Bridge
  4. East Duwamish Waterway Bridge
  5. Spokane Street Swing Bridge
  6. Harbor Avenue Bridge A
  7. Harbor Avenue Bridge B
  8. Harbor Avenue Bridge D
  9. Harbor Avenue Bridge E (note bridge C was destroyed in the 1949 earthquake)
  10. Fauntleroy Expressway    

Each of these ten bridges is a separate structure, built at different times, although many are connected end to end.

The terminology used to describe different bridges varies greatly.  Often it is due to regional preference to one term over the other.  Or it may be due to the common terminology used in the era in which the bridge was constructed.  In general, the term “viaduct” is used to describe a bridge that does not cross a particular geographic feature such as a river or a canyon, and generally does not change elevation.  So, it is simply an elevated street that allows vehicles to travel along without stopping for cross streets or railroad tracks.  In Seattle, examples are the Alaskan Way Viaduct and the Spokane Street Viaduct.  Viaducts are always bridges.  An “expressway” is a term that became popular in the 50’s and 60’s and was used to describe a roadway that had very few cross streets or other interferences to continued travel.  In the case of the Fauntleroy Expressway, it consists of a bridge (or viaduct) section and then a section on ground, west of Harbor Avenue as the roadway travels uphill towards 35th Avenue SW.  There are no interruptions between the start of this expressway near Delridge Way and the traffic signal at 35th Avenue SW.  Not all Expressways are bridges.

So, if you are a motorist traveling from I-5 to the West Seattle Junction for example, although it may seem like one continuous corridor, you are actually traveling on three sections of the upper Spokane Street corridor – the Spokane Viaduct from I-5 to East Marginal Way; the West Seattle High-level Bridge (now known as the Jeanette Williams Memorial Bridge) from East Marginal Way (crossing over Harbor Island) to Delridge; and the Fauntleroy Expressway from Delridge to just west of Avalon (by the sculptures).