Railway tracks are seen in the NEAT Gotthard Base tunnel near Amsteg September 3, 2014. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016. The project consists of two parallel single track tunnels, each of a length of 57 km (35 miles). The tunnel will open in 2017. REUTERS/Ruben Sprich (SWITZERLAND - Tags: BUSINESS CONSTRUCTION TRANSPORT SOCIETY)