Weekend closures

Dec 20, 2023

MERCER ISLAND – The next two September weekends will significantly affect traffic on westbound Interstate 90 on the west side of Mercer Island with lane and ramp closures beginning after the Friday morning commute and lasting until early Monday both weeks.

The first begins at 10 a.m. Friday, Sept. 16, and closes the West Mercer Way on-ramp to westbound I-90, as well as the bike path across the I-90 Homer Hadley Bridge. This will likely affect Mercer Island residents more significantly.

The following week a bigger closure will affect people who regularly use I-90 from the Eastside and across Mercer Island – all westbound lanes of I-90 will be closed west of Island Crest Way from 10 a.m. Friday, Sept. 23, to 5 a.m. Monday, Sept. 26. People will need to either use I-405 to go around Lake Washington or take State Route 520, a toll bridge, to cross the lake.

During these closures, contractor crews working for the Washington State Department of Transportation will replace an expansion joint that connects the bridge to Mercer Island.

The first weekend's work requires crews to close the West Mercer Way on-ramp to westbound I-90. People on Mercer Island still will be able to get onto westbound I-90 via the East Mercer Way and North Mercer Way on-ramps.

In addition to closing the West Mercer Way on-ramp on Friday, contractor crews also will close the right lane of westbound I-90. The right half of the expansion joint runs across the right lane through the on-ramp and across the bike path, which also will be closed for the weekend.

This closure actually will start with westbound I-90 reducing to one lane on Mercer Island at 2 p.m. Thursday, Sept. 22. All lanes will then close at 10 a.m. Friday, Sept. 23 (the on-ramp from West Mercer Way will remain open to westbound I-90.) All lanes will reopen by 5 a.m. Monday, Sept. 26.

The Sept. 23-26 closure coincides with a Seattle Seahawks home game on Sunday, Sept. 25. Closures during large events are not ideal but in this case it can't be avoided, WSDOT Project Engineer Shawn Wendt said.

"We have been trying to schedule this work for several months, but supply chain issues have pushed us back into September, and we need to finish the project this fall while there is still good weather to allow the concrete to cure," Wendt said. "This expansion joint is old and needs to be replaced. If it were to break, that would require an emergency repair that could affect peak traffic periods. By scheduling the work and announcing it ahead of time, people have an opportunity to plan around it."

To help keep everyone moving, travelers, especially those headed to the game, should plan ahead and take transit and alternate routes or alter trips where possible.

In the coming years WSDOT has major projects on I-90, I-405, SR 520 and I-5 – as well as other state highways – that likely will overlap and require multiple major closures at the same time.

"The coming summer travel seasons will be challenging and we ask the public's patience as we share steps to help reduce congestion and stay informed," Wendt said.

People who are traveling can get real-time traffic information on mobile phones with the WSDOT traffic app and by following the WSDOT traffic Twitter feed.