Great progress by demolition and construction crews means the Alaskan Way Viaduct is expected to reopen midday Saturday between the West Seattle Bridge and the Battery Street Tunnel, a move expected to help relieve recent regional traffic congestion on Interstates 5 and 405 and local streets.

Starting this weekend, drivers will travel on a new, temporary construction bypass that will allow an estimated 110,000 vehicles a day to keep moving while construction on a replacement State Route 99 tunnel continues through the end of 2015.

Quick work by demolition crews allowed them to beat the scheduled Monday reopening of the viaduct by nearly two days.

“This project is six months ahead of schedule and today we’re again ahead of schedule,” Gov. Chris Gregoire said. “Thank you to the hard workers on this project, and the people of the region who were patient, found alternate routes and adjusted their schedules. Everyone showed a great spirit of cooperation.”

“Commuters made the difference by doing their part to find other ways and times to travel, which allowed our crews to close this key route for an intense period of work,” state Transportation Secretary Paula Hammond said. “Our crews worked aggressively to accomplish a massive amount of demolition during the longest closure we've ever attempted on a major state highway.”

The clock began ticking Oct. 21 when crews working for the Washington State Department of Transportation closed the highway and launched their effort to aggressively demolish the southern mile of the seismically vulnerable viaduct. In about eight days, a 2,825-foot-long stretch of double-decked highway was reduced to thousands of tons of concrete rubble and steel rebar.

“Through the week, construction crews made rapid progress on demolition and debris removal, and had good weather for things like roadway striping,” said Matt Preedy, WSDOT Alaskan Way Viaduct replacement program deputy administrator. “Thanks to our contractor’s thoughtful planning and approach, we are able to reopen the roadway early and give it back to drivers.”

SR 99 reopening details:

- Northbound and southbound SR 99 are expected to open midday Saturday from the Battery Street Tunnel to the West Seattle Bridge.

- The on-ramp to northbound SR 99 from South Royal Brougham Way is expected to close at 6 a.m. on Saturday, Oct. 29 and reopen once crews finalize roadway connections.

- The southbound SR 99 off-ramp to South Atlantic Street will remain closed until 5 a.m. Monday, Oct. 31.
Drivers can expect a slower, 40 mph speed limit on much of the viaduct between the Battery Street Tunnel and the West Seattle Bridge.

- Drivers can expect a recommended 25 mph construction zone speed limit through the curving bypass in the SODO area.

- Metro Transit’s 11 bus routes that travel on SR 99 will begin using the new bypass at the start of service on Sunday morning, Oct. 30.

Until the viaduct reopens, drivers will face heavy regional congestion that this week was focused on I-5 and I-405 and parts of the downtown Seattle street grid. Commuters are encouraged to plan ahead and consider alternate routes tonight.

Weekend events

Drivers should plan ahead for many special events in the downtown Seattle area this weekend – including home football games for both the University of Washington and Seattle Seahawks. SDOT encourages motorists to consider trying one of the many alternate modes of transportation available - Metro Transit, the West Seattle Water Taxi, the Sounder commuter train, Link light rail, carpool, bicycle, or even walking, if feasible.