Once the Alaskan Way Viaduct is demolished, buses from West Seattle and Southwest King County will need a new permanent pathway to and from downtown Seattle.

The City of Seattle and King County Metro evaluated several potential pathways, including surface streets and Interstate 5, to connect buses from State Route 99 and the West Seattle Bridge to the Third Avenue Transit corridor in downtown Seattle.

We eliminated several pathways because of  traffic conflicts, significant likely impacts on transit reliability, difficulty with turns, and other challenges that would prevent delivery of high-quality transit service to the downtown Seattle core.

Here are some of the pathways Metro and the city evaluated and removed from further consideration:

Interstate 5

  • High traffic volumes and poor transit reliability, depending on time of day.
  • Greatest travel distance between West Seattle and downtown Seattle compared to other pathways.
  • Poor connection to stadiums and other key downtown areas.

First Avenue S and Fourth Avenue S (as combination pathways)

  • Significant travel time increases (5-8 minutes, depending on direction of travel).
  • Poor reliability due to at-grade train crossings—which can delay buses up to 20 minutes—and more than 200 stadium events each year.
  • Would require right-of-way acquisition for transit lanes and other improvements, estimated at $20-30 million. A Lander Street overpass would cost an estimated $200 million.

Airport Way (in combination with other streets)

  • Poor transit reliability.
  • Not all routes that currently use the viaduct can connect to Airport Way.
  • Would not allow buses to serve the SODO area.
  • Poor connection to the stadium area.

Yesler Way and James Street (as both single-street pathways and in combination with other streets)

  • Conflict with ferry operations, as cars and other vehicles access the terminal via Yesler Way.
  • Turns that are difficult for buses to make.
  • Pedestrian conflicts.
  • Added travel time due to turns.

Jackson Street (as both a single-street pathway and in combination with other streets)

  • Higher traffic volumes are expected on Jackson Street with the new Alaskan Way surface street.
  • Right-of-way constraints due to First Hill Streetcar operation.
  • Increased turns and pedestrian conflicts.
  • Difficult turns for buses.

Main Street and Washington Street (as both a single street pathway and in combination with other streets)

  • Extensive street improvements would be required.
  • Neighborhood concerns over potential effect on historic district.

Given input from riders and neighborhoods, as well as the pathways analysis, the city and Metro are now focusing on evaluating a two-way Columbia Street pathway.

Once the necessary transit improvements are made, Columbia Street will be the fastest, more reliable pathway. It will provide improved connections to the stadium and waterfront area. Improvements needed to make this pathway work for transit riders include transit priority measures, street and intersection modifications, multi-modal connections at Colman Dock, and enhanced bus stop locations. For more details about the pathways studied, read Metro’s full report.