The Wednesday morning commute through downtown Seattle went sideways in a hurry as the SR 99 tunnel was suddenly closed in both directions for emergency maintenance. Crews moved in quickly to seal off the roughly two-mile underground route so technicians could inspect and address an immediate problem, and officials warned there was still no timeline for when traffic would be allowed back in. Drivers were urged to build in extra time and find alternate ways around downtown.
According to KING 5, the Washington State Department of Transportation said "there is currently no estimate for when the tunnel will reopen." The agency is asking motorists to avoid SR 99 while crews work and says updates will be pushed out through its official channels.
What drivers should know
The sudden shutdown is shoving more vehicles onto Interstate 5 and already-busy surface streets, piling even more congestion onto the morning rush. The SR 99 tunnel, a double-decked bore that replaced the Alaskan Way Viaduct, is a primary north-south artery beneath downtown, so any full closure tends to ripple across multiple corridors. Travelers are being urged to look at transit options, pad their travel time, or reroute using I-5 or key surface arterials, as explained by The Seattle Times.
Recent unplanned closures
Unplanned shutdowns are nothing new for the tunnel. A power outage briefly took SR 99 offline on Nov. 20, 2025, and the route did not reopen until power and ventilation systems were restored. That episode, which delayed commuters for several hours, was reported by KIRO 7 and showed how quickly technical issues can snowball into major travel headaches. For now, officials say they are prioritizing a safe, thorough inspection before letting traffic back into the tunnel.
Where to get updates
WSDOT says it will post real-time information on its online traffic tools and social media accounts. Travelers can check the traffic map from the Washington State Department of Transportation and tune in to local outlets such as KING 5 and other broadcasters for the latest detours, reopening estimates, and commute tips as the situation develops.
