Plan ahead for construction on westbound I-90 Jan. 22-25

Washington State Department of Transportation


Drivers heading west across Lake Washington should plan ahead for construction and delays Jan. 22-25. Contractor crews working for the Washington State Department of Transportation and Sound Transit will continue upgrading the operations and safety systems inside the Mount Baker and Mercer Island tunnels as part of a project to add new around-the-clock HOV lanes to Interstate 90.

Beginning at 11 p.m. Friday, Jan. 22, the crews will reroute all westbound lanes of Interstate 90 to the express lanes between Bellevue Way Southeast and Rainier Avenue South until 5 a.m. Monday, Jan. 25.

“We’ve completed a lot work of the past year,” said project engineer Aleta Borschowa. “Not all of it is glamorous, and a lot of it is taking place in the ceilings or walls of the tunnels and out of the view of drivers.”

Some of the highlights include placing more than a mile of electrical and fiber optic conduit that will connect to the thousands of holes contractor crews have drilled in the tunnel ceilings for new lights, cameras and fire detection equipment. Crews have also upgraded electrical systems that will power the new and improved tunnel ventilation and safety systems, and built a new emergency access corridor in the westbound Mount Baker Tunnel.

“We’re almost halfway but we have a lot of work to go,” said Borschowa. “We want to make sure that tunnels are ready to keep folks safe and get things ready for light rail.”

Building the new HOV lanes on the outer roadways of I-90 will enable construction of Sound Transit’s 14-mile East Link light rail extension from Seattle to Redmond in the express lanes.

Closure details

11 p.m. Friday, Jan. 22, until 5 a.m. Monday, Jan. 25

  • Westbound I-90 traffic between Bellevue Way Southeast and Rainier Avenue South is routed to the express lanes.
  • Mercer Island traffic will need to exit westbound I-90 at East Mercer Way. There are no westbound exits to Mercer Island from the express lanes.
  • Drivers heading to Seattle from Mercer Island should use the 77th Avenue Southeast or Island Crest Way express lane on-ramps.
  • The westbound I-90 exits to Rainier Avenue South will be closed. Drivers should follow the signed detour via Fourth Avenue South and eastbound I-90.
  • Flammable materials will be prohibited on westbound I-90. Drivers must use alternate routes such as I-405, SR 520 or SR 522.
  • The I-90 Trail will not be impacted during the closure.

Special events

University of Washington women’s basketball at Alaska Airlines Arena

  • 2 p.m. Saturday, Jan. 23

 Seattle University men’s basketball at KeyArena

  • 7 p.m. Saturday, Jan. 23

 University of Washington men’s basketball at Alaska Airlines Arena

  • 530 p.m. Sunday, Jan. 24

 WSDOT needs help from drivers to keep traffic moving Thousands of vehicles travel across the I-90 floating bridge on a typical weekend. WSDOT needs drivers’ help to prevent regional gridlock during a weekend closure:

  • Know before you go: check the Seattle traffic website, call 511 for real-time travel information, and plan for delays and added travel time.
  • Allow extra time to travel westbound on I-90 or on alternate routes.
  • Ride transit, carpool or use other alternative modes of transportation.
  • Travel early in the morning or later in the evening, or reschedule discretionary trips.
  • Expect congestion on alternate routes such as I-405, I-5 and SR 520.
  • During the day drivers should expect increased congestion on local streets, especially Rainier Avenue South, Fourth Avenue South and South Dearborn Street in Seattle; and Bellevue Way Southeast in Bellevue.