All drivers should be aware that westbound I-90 will once again be detoured to the express lanes from 11 p.m., Friday, April 17 to 5 a.m. Monday, April 20, but that the Washington State Department of Transportation (WSDOT) has made some changes in traffic control from the Eastside to Mercer Island.

During the closure drivers heading to Mercer Island must exit at East Mercer Way. After that point, there are no westbound exits onto Mercer Island from the express lanes. If traveling from Mercer Island to Seattle, drivers can enter the express lanes at Island Crest Way or 77th Avenue S.E.

The exit from westbound I-90 to Rainier Avenue South will be closed. Drivers should follow the signed detour to reach Rainier Avenue South during the closure.

There are no impacts to cyclists and pedestrian using the I-90 trail during the weekend closure.

This is the third of approximately 30 work closures over the next two years while the state builds bus and carpool lanes next to the regular lanes, so the center roadway can be dedicated to Sound Transit light rail construction in 2017.

WSDOT spokeswoman Annie Johnson said that the agency received a lot of feedback after the March 27-30 weekend closure that “things were confusing” for Mercer Island residents.

According to a WSDOT blog post, after every major closure for construction or maintenance work, the agency asks, “How did it go, and how can we make it better?”

WSDOT will implement some changes this weekend, that “won’t take away traffic congestion – you should still plan on leaving as early as possible and consider alternate routes – but it should address some of the major concerns,” according to the post.

All traffic for Mercer Island must still exit westbound I-90 at East Mercer Way. During the previous detour, there was confusion for some drivers on Bellevue Way and on I-90 as to how to get to the East Mercer Way exit, leading some to drive through closed areas, which is never a good idea.

“Last time, we moved everyone to the left, and Mercer Island traffic had to move to the right. We’re doing the opposite this time – moving everyone to the right,” Johnson said, noting that there will also be two lanes open instead of one. 

WSDOT is also adding more signage to make it clear which lane I-90 drivers should be in for Mercer Island (the right) and for Seattle (the left). Bellevue Way drivers will be able to use their more familiar I-90 ramp that leads directly to East Mercer Way (last time they could only use the I-90 HOV ramp) and westbound I-90.

The challenge of that area is that there are so many ramps – from Bellevue Way, Eastgate and I-405, and there’s only one lane in and out of the I-90 express lanes, Johnson said.

“This is the third of 30 directional closures of I-90 we’ll have for this project through mid-2017 and each one will be a chance for us to learn and make the next one smoother,” according to the post. “[But} anytime you close lanes on a major highway, traffic shifts to other places and it creates challenging traffic so please, if you’re going to the Mariners game, the Snoop Dogg concert or any other place this weekend, add plenty of extra time to your trip, be patient and plan your route ahead of time.”

Extra signage and added law enforcement are some of the changes drivers will see to ease confusion during this weekend’s westbound I-90 detour.

Click here for the WSDOT Detour Page.