The Alaskan Way Viaduct replacement tunnel, is a $3.3 billion , double-decker bored highway tunnel under Downtown Seattle. Construction began in July 2013 using "Bertha", at the time the world's largest earth pressure balance tunnel boring machine, with a cutterhead diameter. After several delays, tunnel boring was completed in April 2017, and the tunnel opened to traffic on 4 February 2019.
The Alaskan Way Viaduct replacement tunnel is a $33 billion  double-decker bored highway tunnel under Downtown Seattle Construction began in July 2013 using "Bertha" at the time the world's largest earth pressure balance tunnel boring machine with a cutterhead diameter After several delays tunnel boring was completed in April 2017 and the tunnel opened to traffic on 4 February 2019