When will the SR 99 tunnel in Seattle be closed?

The SR 99 downtown tunnel will be fully closed Friday night from 10 p.m. to Saturday 6 a.m. for maintenance.

What are the SR 99 lane closures this week in Seattle?

Closures include a northbound lane Monday night, southbound lanes Tuesday night, and various ramps throughout the week.

How can I avoid SR 99 closures in downtown Seattle?

Drivers can reroute their travel to I-5 to bypass the SR 99 maintenance closures.

Home / Disasters and Accidents / Downtown Seattle SR 99 Tunnel Maintenance

Downtown Seattle SR 99 Tunnel Maintenance

2 Dec, 2025

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Summary

Northbound SR 99 tunnel lane closures occur Monday night.
Southbound SR 99 off-ramp to Harrison Street closes Tuesday.
SR 99 downtown tunnel fully closes Friday night for maintenance.

Downtown Seattle SR 99 Tunnel Maintenance

The Washington State Department of Transportation (WSDOT) has announced a series of lane and ramp closures affecting SR 99 in downtown Seattle this week. These disruptions are scheduled to occur during late evening and early morning hours to minimize impact on the daily commute. Motorists are advised to plan for detours or consider alternative routes, such as I-5.

Specific closures include the right lane of the northbound SR 99 tunnel and the Royal Brougham Way on-ramp on Monday night. On Tuesday night, two left lanes of southbound SR 99 north of the tunnel will be closed, along with the Harrison Street off-ramp. The Sixth Avenue N. on-ramp to southbound SR 99 will be closed on Wednesday night.

This maintenance period culminates in a full closure of both directions of the SR 99 downtown tunnel from Friday night into Saturday morning. Crews will use this time to remove vegetation, with plans for future replanting. The schedule begins late Monday and concludes early Saturday.