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Night and weekend closures next week for SR 99 tunnel work

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Date:  Friday, June 08, 2012

Contact: Travis Phelps, Alaskan Way Viaduct Replacement Program, (cell) 206-462-0554 (Seattle) 
KaDeena Yerkan, Alaskan Way Viaduct Replacement Program, 206-805-2846, (cell) 206-795-1876 (Seattle)

Both directions of the viaduct will close June 15-18

SEATTLE – Drivers should expect a series of closures of the State Route 99 Alaskan Way Viaduct next week as crews continue to reinforce a two-block section of the structure located above the route of the future SR 99 tunnel.

SR 99 tunnel crews will close the southbound lanes of the viaduct Monday through Thursday nights, June 11 through 14, and then close both directions of the viaduct starting Friday night, June 15, until the morning of Monday, June 18.

Crews will use both closures to continue wrapping a protective reinforcing fiber around the concrete beams of the viaduct’s upper deck between South Washington and Columbia streets in Pioneer Square. The fiber will protect this section of the viaduct when crews drive the tunnel boring machine beneath it in late 2013.

“Protecting this section of the viaduct is a precaution that helps us keep the SR 99 corridor open during tunnel construction,” said Matt Preedy, WSDOT Alaskan Way Viaduct Replacement Program deputy administrator. “We are doing our best to minimize the number of times we have to close the viaduct as we continue to prepare for tunneling.”

Closure details
: The southbound lanes and on-ramps of the SR 99 Alaskan Way Viaduct between the north end of the Battery Street Tunnel and the West Seattle Bridge will close nightly from 9 p.m. to 5 a.m. June 11 through June 14.

Weekend work: Both directions of the SR 99 Alaskan Way Viaduct and all on- and off-ramps will close around the clock from 11 p.m. Friday, June 15 to 5 a.m. Monday, June 18, between the West Seattle Bridge and the north end of the Battery Street.

Drivers traveling in and near downtown Seattle, including fans headed for next weekend’s Mariners games, should plan for increased congestion and consider leaving early, carpooling or taking transit. Up-to-the-minute traffic information is available at and via the Washington State Department of Transportation’s voice-activated driver information line, 511.

The tunnel boring machine is currently being manufactured in Japan and is expected to arrive in Seattle early next year. It is designed specifically for the soil and groundwater conditions along the route of the future SR 99 tunnel. Although engineers do not anticipate significant levels of ground settlement, they are monitoring structures above and near the tunnel route as a precaution.

Additionally, crews are building underground walls beneath the viaduct’s foundations to further safeguard the structure.

For more information on the Alaskan Way Viaduct Replacement program, visit

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