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Milepost 31 marks first anniversary, eyes a big 2013

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Date:  Wednesday, December 05, 2012

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

Information center preps Seattle for arrival of the SR 99 tunnel-boring machine

SEATTLE – Last December, Milepost 31 opened its doors and welcomed its first guests. One year and 7,000 visitors later, the Washington State Department of Transportation's first-ever public information center is eager to welcome one guest in particular: the world's largest-diameter tunneling machine.

In conjunction with Pioneer Square’s First Thursday Art Walk, Milepost 31 will mark its one-year anniversary at 6 p.m. Thursday at 211 First Ave. S. The event includes a presentation on the city of Seattle's Elliott Bay Seawall Project and opportunities to view exhibits and talk to staff about the record-breaking machine that will dig a tunnel to replace the waterfront section of Seattle's Alaskan Way Viaduct.

“The tunnel project is about to reach historic proportions,” said WSDOT's Alaskan Way Viaduct Replacement Program Administrator Linea Laird. “The world has never seen a tunneling machine this big, and Milepost 31 is a great way for the public to connect to the project and track its progress.”

Currently being assembled in Japan, the 57.5-foot-diameter machine is scheduled to arrive in Seattle in March 2013 and begin digging next summer. An interactive, 10-foot-long replica of the machine is on display now at Milepost 31, alongside exhibits about the seawall and the city’s plans for the post-viaduct waterfront.

It's been a busy year for Milepost 31, which pairs tunneling technology with local history as part of a federal requirement to mitigate the effects of construction to replace the viaduct. In addition to keeping regular hours and hosting monthly speakers and special events, the center collected a number of awards in 2012, including the King County Executive's John D. Spellman Award for Exemplary Achievement in Historic Preservation, the Washington Museum Association for Project Excellence and the American Association for State and Local History merit award.

Visitors to Milepost 31 – named for the point at which SR 99 enters Pioneer Square – can find historic artifacts, 3-D models and pieces of tunneling equipment. Interactive exhibits show how Seattle’s landscape and shoreline have changed during the past 20,000 years, and how crews are building the massive tunnel that will replace the viaduct and reshape the SR 99 corridor.

Milepost 31 is open 11 a.m. to 5 p.m., Tuesday through Saturday. For more information on the Alaskan Way Viaduct Replacement Program, visit


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