I-90 closure will add to weekend traffic congestion around Seattle

The Washington State Department of Transportation is taking advantage of a rare weekend without major sporting events in Seattle by doing another directional closure of the I-90 bridge.

All westbound drivers are going to be squeezed into the express lanes for their trip across Lake Washington. This will start Friday at 10 p.m. Lanes will reopen late Sunday night or Monday morning.

State DOT spokesperson Annie Johnson says these closures usually translate into heavier traffic on 520 and I-405.

When will WSDOT take care of the Highway 18 chokepoint?

Johnson says the westbound closures can be particularly difficult for people heading to Mercer Island. That’s because the East Mercer Way exit will be the only exit open on the island for westbound drivers over the weekend. If drivers miss that exit they have to drive to Seattle and turn around.

The closure if part the state’s preparation for the two I-90 tunnels for new HOV lanes and the expansion of light rail to Bellevue.

“That project is extending the HOV lane from where it ends in the middle of Mercer Island, across the floating bridges, to about Rainier Avenue in Seattle,” Johnson said. “It will also enable ST to build east link light rail in I-90 express lanes.”

There will also be a directional closure of Highway 18 as the state works on improvements on the back side of Tiger Mountain. At alternating times Friday night and Saturday, the eastbound and westbound lanes of Highway 18 between Issaquah-Hobart Road and I-90 will be closed. Westbound will be closed Friday night. Eastbound will be closed Saturday night. These are nighttime closures only.

And don’t forget, the Port Townsend-Coupeville ferry run will not be operating Saturday and Sunday as the Coupeville dock gets a seismic update. Expect longer waits at the Mukilteo-Clinton and Edmonds-Kingston terminals.

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