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SR 520 - West Approach Bridge North Project History


Federal approval for design and construction

The West Approach Bridge North (WABN) is one phase of the I-5 to Medina: Bridge Replacement and HOV Project. WABN is not a change to the overall project.

When WSDOT completed the environmental process for the I-5 to Medina project in 2011, the final environmental impact statement identified phased construction, starting with the west approach bridge.

When the preferred alternative design was announced in April 2010, it called for building the new west approach bridge in two parts, a north half and south half, with a gap in the middle to accommodate future light rail if funded and approved by the region.


City of Seattle and stakeholder coordination

In 2011 and 2012, WSDOT engaged with multiple stakeholders, including the Seattle Design Commission and the public, through the Seattle Community Design Process (SCDP) to further refine the baseline design of the project.

In September 2012, WSDOT convened a technical working group with multiple city of Seattle department representatives to guide the project team’s development of technical design details. As an extension of SCDP coordination, WSDOT also continued to work with the Seattle Design Commission (SDC) on key bridge design elements. The SDC approved the conceptual design of the major bridge elements, with the understanding that WSDOT would continue to coordinate with them through final design. 

On Feb. 5 and 6, 2013, WSDOT hosted SR 520 Program Open Houses on the east and west side of Lake Washington to share project information with Seattle neighborhoods and the broader public. View the open house materials (pdf 6.87 mb).

In February 2013 the Seattle City Council approved Resolution 31427, recommending a simple, clean structural design for the West Approach Bridge North. In line with this resolution, project elements in the Montlake area will:

  • Ensure working interim connections
  • Allow for future transportation improvements and amenities, including the Montlake Lid
  • Minimize and mitigate project impacts in the surrounding community
  • Integrate with the I-5 to Medina project’s final project design, as outlined in the Preferred Alternative.

Recent developments

The West Approach Bridge North Project (WABN) contract was advertised and opened for bids in April 2014. Flatiron West, Inc. was awarded the contract in July 2014 at $199.5 million. Construction of the WABN project began in September 2014.