The world’s largest-diameter tunnel-boring machine will arrive in Seattle next year to carry out the tunnel building proccess for the SR 99 tunnel. On Thursday Sept. 6 the Washington State Department of Transportation is inviting the public to tour the area of the work zone for the project.

The tour is a mile-long, round-trip walk along the bicycle/pedestrian path adjacent to the construction site. Visitors will see crews dig the launch pit for the 300-foot-long tunnel-boring machine and get explanations of the equipment being used to do the work.

“There’s a lot of amazing equipment and activity happening on site right now and we want people to see and understand what’s going on,” said Linea Laird, Alaskan Way Viaduct Replacement Program administrator. “This is the first of many opportunities we’ll offer for a better glimpse of construction.”

Work crews are currently digging the 80-foot-deep pit where the machine will begin boring the tunnel. Also under construction is a new overpass and the completion of a new section of SR 99 which will replace the south end of the Alaskan Way Viaduct.

The tour will begin at Milepost 31, the Alaskan Way Viaduct Replacement Program’s information center in Pioneer Square. This center houses interactive exhibits, a model of the SR 99 tunnel-boring machine and the latest project information.

Walking tour details
6 p.m., Thursday, Sept. 6
Meet at Milepost 31, 211 First Ave. S., Seattle

For those who can’t attend, a new self-guided tour is available. Displays have been installed along the bicycle/pedestrian path to describe construction activities, machinery at work and the area’s history. Access to the path’s north entrance is available at South King Street and Alaskan Way South, a few blocks south of Colman Dock, or the south entrance is at South Atlantic Street and Alaskan Way South, west of Safeco Field. Maps are available at Milepost 31.

Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org/ and Milepost 31, which is open 11 a.m. to 5 p.m. Tuesdays through Saturdays and is open late during Pioneer Square’s First Thursday Art Walk. Admission to Milepost 31 is free.