A look inside construction of Seattle tunnel’s double-deck highway
By MICHAEL KONOPASEK Q13 News SEATTLE -- As the tunnel-boring machine Bertha takes a break, the public is getting its first look inside the elaborate construction of the tunnel’s double-deck highway. Thousands of commuters see the surface construction work along the Alaskan Way Viaduct every day, but what they can't see is 120 feet below downtown Seattle. As Bertha continues to move forward, southbound lanes are being built on the top half of the tunnel. Northbound lanes are being constructed on the bottom half.