I-90 Two-Way Transit Project

Image of I-90 bridge

The I-90 Two-Way Transit & HOV Operations project will improve regional mobility by providing safe and reliable two-way transit on I-90 between Bellevue and Seattle. The WSDOT and Sound Transit project will provide full-time HOV lanes for eastbound and westbound traffic on the outer I-90 roadways and new direct-access ramps for transit and HOVs on Mercer Island and in Bellevue. This collaborative project will prepare the center roadway for the East Link Extension.

The project is being implemented in stages due to timing and availability of funding.

Location: Eastbound and westbound I-90 between Rainier Avenue in Seattle and 80th Ave SE in Mercer Island

Current project phase: Phase 3 construction

Budget: $223 million

Planning partners: Sound Transit, City of Mercer Island, City of Seattle, Washington State Department of Transporation and King County Metro Transit


Stage 1: Completed in October 2008

  • Added a new HOV lane in the westbound I-90 outer roadway between Mercer Island and Bellevue.

  • Built a new HOV direct access ramp at 80th Ave SE.

  • Modified the pre-existing Bellevue Way HOV direct access ramps for two-way transit operations.

Stage 2: Completed in March 2012

  • Mercer Island's 80th Ave SE ramp is functioning as an on-ramp to the eastbound I-90 outer roadway for carpools and buses only with direct access to a new HOV lane to Bellevue.
  • Provided an HOV lane on eastboound I-90 between Mercer Island and Bellevue.
  • Modified the existing reversible HOV ramp at 80th Ave SE on Mercer Island to a HOV on-ramp connecting directly to the new eastbound HOV lane.
  • Extended the eastbound I-90 to I-405 auxiliary lane and modified the Bellevue Way & I-405 HOV direct access from the eastbound HOV lane.

Stage 3A: Construction finished in May 2015.

  • Reconstruct and reposition the HOV ramps from eastbound I-90 to Bellevue Way and I-405

Stage 3: Construction began in January 2015 and is expected to be complete in mid-2017

  • Will add an HOV lane to the outer roadways in both directions between Rainier Ave in Seattle and the 80th Ave SE in Mercer Island.
  • Will make improvements to the fire and life safety systems in the Mt. Baker tunnel and the Mercer Island lid.
  • Preserve pavement in both directions, I-5 to Lake Washington.
  • Will build an eastbound HOV direct-access exit ramp at Island Crest Way on Mercer Island.

* Construction schedule subject to change

 For detailed construction updates, visit the Washington State Department of Transportation website: http://www.wsdot.wa.gov/projects/i90/twowaytransit/ .