SEATTLE – Two of three eastbound lanes through the Mt. Baker Tunnel on Interstate 90 will be closed from 11 p.m. Saturday, Dec. 10, to 8 a.m. Sunday, Dec. 11. A crew for the Washington State Department of Transportation will be installing video cameras to test new technology to detect and respond to emergencies inside the tunnel.
 
The closure will affect only the north-side lanes of the divided eastbound tunnel. A single eastbound lane in the south side of the tunnel will remain open to traffic. During the closure the center express lanes on I-90 will operate eastbound, the normal weekend direction, however buses and HOVs will not be able to access the center express lanes east of the Rainier Avenue exit. Express lane access on Mercer Island will not be affected.
 
The work is part of the I-90 Two-Way Transit and HOV Operations project, Stage 3. The existing fire and life-safety system in the tunnel uses heat sensors to detect a possible fire. The new cameras will combine visual sensors with video monitoring to provide WSDOT traffic engineers faster, more detailed information about emergencies for better response.