WSDOT Traffic Advisory
Nov. 24, 2010
SR 99 downtown Seattle ramp closures
SEATTLE – Drivers can expect detours at the two Belltown SR 99 on-ramps and the northbound SR 99 off-ramp to East Marginal Way S. on Monday, Nov. 29 through the morning of Friday, Dec. 3. During the closures, WSDOT contractor crews will install traffic gates and supporting equipment for a new Alaskan Way Viaduct automated closure system.
• Monday, Nov. 29 and Thursday, Dec. 2 – The Bell Street/Western Avenue on-ramp to the northbound SR 99 Battery Street Tunnel will be closed from 7 a.m. to 3 p.m. both days. Drivers will be detoured to Western Avenue. The closest northbound SR 99 on-ramp is located at the intersection of Denny Way and Aurora Avenue N.
• Monday, Nov. 29 to the morning of Thursday, Dec. 2 – The Elliott Avenue ramp to southbound SR 99 will be closed from 10 p.m. to 5 a.m. nightly. Drivers will be detoured to First Avenue. The closest southbound SR 99 on-ramp is located at the intersection of First Avenue and Columbia Street.
• Thursday, Dec. 2 to the morning of Friday, Dec. 3 – The northbound SR 99 off-ramp to East Marginal Way S. will be closed from 10 p.m. to 5 a.m. Drivers will be detoured onto First Avenue S. Freight haulers will be detoured onto East Marginal Way S.
WSDOT began work to install an automated viaduct closure system in September 2010. The new system consists of nine traffic gates placed at or near on-ramps to the Alaskan Way Viaduct and controlled by an earthquake detection system. It is designed to safely close the viaduct within two minutes of detecting a significant earthquake – one strong enough to weaken the viaduct. Crews expect to complete the project in early 2011.
The system will be in operation until the viaduct is replaced. Learn more about the project: www.wsdot.wa.gov/Projects/SR99/ViaductClosureSystem/