Japan–Korea Undersea Tunnel at about ₩100 trillion (approx. US$90 billion), which would produce an extremely low benefit-to-cost result. In 2014, the South Korean Busan Development Institute estimated the undersea tunnel could create ₩54 trillion won (원54T, or US$53 billion) in economic benefits and provide about 45,000 jobs. In an April 2009 editorial, former Justice Ministers Daizō Nozawa of Japan and Kim Ki Chun of South Korea remarked on some of the similarities of the proposed Japan–Korea tunnel to the world's present longest undersea tunnel. The Channel Tunnel runs for 50.45 km linking the United Kingdom and France, and opened in May 1994: At
Severn Tunnel Severn between Sharpness and Lydney opened to traffic during 1879. On 22 October 1884 laying the double tracks in the tunnel started. On 18 April 1885, the final brick was placed in the tunnel's lining. The tunnel was horse shoe-shaped in cross-section with a concave floor, its height was 6.1 meters above the rails with a maximum width of 7.9 meters. An enclosed 533mm high drainage channel, in the form of an upturned semi-circular tunnel, is built onto the tunnel invert, 1.4 meters below the rails. Around 76.4 million bricks were used in the tunnel's construction. The brickwork is between