The Canadian city of Ottawa currently has the highest usage of its public transportation system if any city of its size in North America, and that usage is expected to continue to grow.
In order to meet the demand, the city is building a new line that includes a 2.5-kilometer tunnel with three underground stations in the downtown area.
Construction began in 2013. The project is using three Sandvik MT720 roadheaders to excavate the tunnel. The MT720 machines were chosen for their economy as well as the low levels of noise and dust they produce. The Confederation Line will open to the public in 2018.