Traffic alert: SR-99 tunnel to close in both directions starting Dec. 1

SEATTLE — Starting on December 1, the State Route 99 tunnel will be closed in both directions for scheduled maintenance.

The closure will last until 6 a.m. on Saturday.

Crews will inspect fire extinguishers and fire sprinkler visual inspections. They will also lubricate and test the jet fans, and fix the tunnel lighting along with other repairs.

Further south, I-405 southbound will close between Monday Dec. 4 and Thursday Dec. 7 at 11 p.m. The roadway will reopen at 4:30 a.m. each morning. This will be to set new girders for an overpass that was torn down when it was damaged by a semi-truck trailer.

©2023 Cox Media Group