All eastbound lanes of Interstate 90 between Seattle and Mercer Island will close overnight on Friday, November 6, 2026, for tunnel maintenance, the Washington State Department of Transportation (WSDOT) has warned — a full closure of one of the busiest commuter and freight corridors in the Seattle area, timed for the Friday-night hours when traffic is lighter but weekend travel is under way.
Source: WSDOT Travel Advisory, Nov. 3, 2026
WSDOT says the closure runs from 10 p.m. on Friday, November 6 to 6 a.m. on Saturday, November 7. The City of Mercer Island notes that crews will begin closing lanes earlier, at 8:30 p.m. on Friday, with all eastbound lanes shut by 10 p.m., and all lanes reopening by 6 a.m. on Saturday.
Exactly what is closing
Every lane of eastbound I-90 will close from Rainier Avenue South, at milepost 3 in Seattle, to 77th Avenue Southeast, at milepost 6 on Mercer Island. That stretch carries eastbound traffic out of Seattle, through the I-90 tunnel and across Lake Washington toward Mercer Island, Bellevue and the Eastside.
The on-ramps close with the main line. WSDOT lists the eastbound I-90 on-ramps from both northbound and southbound Interstate 5, and the eastbound on-ramps from both northbound and southbound Rainier Avenue South. A driver who reaches those ramps after 10 p.m. will not be able to join eastbound I-90 at all.
What the crews will do inside the tunnel
WSDOT says its tunnel maintenance crews will use the eight-hour window to perform four jobs: fire systems testing, light repairs, road sweeping and drain cleaning. Fire-system tests and lighting work are safety jobs that can only be done properly with no traffic in the tunnel, and sweeping and drain cleaning clear the debris and water that build up on a heavily used urban freeway.
Lane closures start at 8:30 p.m. and the freeway is fully shut by 10 p.m. Anyone who must travel east from Seattle to Mercer Island or the Eastside on Friday night should leave early or check WSDOT's real-time map before setting out.
Why this corridor matters — including for truckers
Interstate 90 is not a local street. It is the northern coast-to-coast interstate, running from Seattle across Washington and the northern United States to Boston, and its Seattle–Mercer Island section is the first link out of the city for eastbound freight as well as for commuters. A full eastbound closure, even overnight, pushes Friday-night trucks and cars onto a small number of other Lake Washington crossings and city streets.
The readers WSDOT and the City of Mercer Island name first are Mercer Islanders, Eastsiders and Seattle-area drivers travelling between Seattle and Mercer Island. For Punjabi truck drivers who run I-90 out of the Seattle–Tacoma port area on Friday-night schedules, the practical point is timing: an eastbound departure after 10 p.m. will meet a closed freeway at milepost 3, so dispatch and departure times need checking before the truck rolls, not at the ramp.
What happens next
All lanes are scheduled to reopen by 6 a.m. on Saturday, November 7. WSDOT says real-time travel information is available through the WSDOT mobile app, the WSDOT travel map at wsdot.com, and by signing up for WSDOT email updates. The advisory, issued on November 3, 2026, lists a WSDOT Northwest Region communications contact, Lauren Padgett. The advisory lists eastbound closures only; it does not announce any westbound closure.
This is scheduled maintenance, not an emergency closure — there has been no crash or incident reported behind it. Drivers should still treat the times as weather- and work-dependent in the usual way and confirm the road is open on WSDOT's real-time channels on Saturday morning before relying on the 6 a.m. reopening.