Seattle-area drivers face multiple weekend closures on I-90, I-405, I-5, and SR 16

Extended lane closures eastbound I-90 at Mercer Island

The Washington State Department of Transportation (WSDOT) is finishing a project on the East Channel Bridge that started with a failed expansion joint in January 2024.

Drivers may recall the massive backups caused during that emergency closure in 2024. This latest project will most likely bring similar backups to eastbound I-90 through Oct. 5, the projected completion date.

For the next 16 days, the one-mile stretch between E. Mercer Way and Bellevue Way will be down to three lanes. It is common to see backups starting in Seattle during peak drive times. This leaves SR 520 as the only option crossing Lake Washington.

WSDOT crews will repair expansion joints during this period.

Overnight closure of westbound I-90 over Lake Washington

The Washington State Department of Transportation (WSDOT) will conduct regular maintenance operations inside the Mercer Island tunnel and the Mount Baker tunnel. Last Friday, WSDOT had this same closure in the eastbound direction.

This week, crews will switch work to the westbound I-90, closing all lanes between Island Crest Way and Rainier Avenue S. Closures begin Friday, Sept. 19, at 10 p.m., with all lanes reopening by 6 a.m., Saturday, Sept. 20.

Westbound I-90 in Issaquah

Beginning Friday, Sept. 19, at 8 p.m., drivers headed west through Issaquah will have a 1-mile stretch at Front Street where two left lanes will be closed for bridge work. The Front Street on-ramp will be closed during this project, which is scheduled to wrap up by 8 a.m., Sunday, Sept. 21.

Crews are scheduled to reduce westbound I-90 to a single lane for two more weekends to continue bridge repairs in Issaquah. The first weekend is tentatively scheduled for Sept. 26-28, while the second will be after the Oct. 4-5 Issaquah Salmon Days festival.

Westbound I-90 off-ramp to SR 18 closed

The westbound I-90 off-ramp to SR 18/Snoqualmie Parkway will close from 9 p.m. Friday, Sept. 19, to 5 a.m. Monday, Sept. 22, to install guardrail and curb work near Snoqualmie.

During the ramp closure, westbound I-90 drivers will have a detour, which loops around at Preston/Fall City (exit 22) and uses the eastbound I-90 off-ramp to SR 18/Snoqualmie Parkway.

In addition to the new diverging diamond interchange, the I-90/SR 18 Interchange Improvements project is widening SR 18 to two lanes in each direction between I-90 and Deep Creek. That work is expected to finish later this fall.

Southbound I-405 lane reductions in Bellevue

WSDOT crews need to reduce lanes  to remove pavement, excavate, complete sewer repairs, and pave to support work on the I-405/Renton to Bellevue Widening and Express Toll Lanes Project

From 11 p.m. Friday, Sept. 19, to 4:30 a.m. Monday, Sept. 22, southbound I-405 lane reductions will be in place from N.E. 70th Place to I-90.

The following southbound I-405 on-ramps also will close:

• N.E. 70th Place
• S.E. Eighth Street

A signed detour route will guide people around the closures.

Northbound I-5 off-ramp to N.E. 130th Street closed

Sound Transit crews will close the northbound I-5 off-ramp to Northeast 130th Street from 10 p.m. Friday, Sept. 19, until 5 a.m. Monday, Sept. 22, to continue work on the Pinehurst Station, which is part of the Lynnwood Link Extension project and is scheduled to open in 2026.

E. Roanoke Street closed on Capitol Hill

Drivers on the north end of Capitol Hill will not have access to E. Roanoke Street just east of the freeway both Saturday and Sunday.

Closure details:

• Crews will close East Roanoke Street between Harvard Avenue and 10th Avenue East each day from 7 a.m. to 10 p.m.
• Uniformed police officers will be on site to guide vehicle and pedestrian traffic around the closure.
• Access will be maintained for emergency services.
• Drivers and pedestrians will need to follow the signed detours.

During the two-day closure, crews will trench and install an underground conduit system for future utility relocation.

Westbound lane closures at Tacoma Narrows Bridge begin Friday morning

The Tacoma Narrows Bridge requires another repair to address an expansion joint issue in the westbound direction.

At 8 a.m. Friday, Sept. 19, the Washington State Department of Transportation (WSDOT) crews will close the two right lanes approaching the bridge, along with the Jackson Avenue on-ramp to westbound SR 16. During the closure, the HOV lane will be open to all drivers. All lanes are scheduled to reopen by 10 p.m. Saturday, Sept. 20.

Once the expansion joint is repaired, crews will pour new concrete. The concrete needs time to cure, so travelers might see lane closures when there appears to be little or no activity in the work zone.

Drivers can expect to see congestion on westbound SR 16 approaching the bridge during the lane closures, and significant congestion approaching the bridge during the afternoon commute Friday, Sept. 19. Drivers should add extra travel time to help prevent delays or consider combining or postponing discretionary trips.

Nate Connors is a traffic reporter for KIRO Newsradio. Follow him on X. Read more of his stories here. Submit news tips here.

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