[3] Work on the Kanmon Roadway Tunnel began in 1937, but was halted in 1939 by World War II.

Work resumed in 1952, and the tunnel was officially opened on March 9, 1958.

Under terms of Article 46.3 of Road Act, driving by vehicles that carry dangerous goods are either prohibited or limited strictly.

A separate pedestrian passage exists, built directly underneath the roadway tunnel.

[4] Due to the advantage of having elevators on either side, the pedestrian segment is only 780 meters long, allowing one to walk under the strait between Honshu and Kyushu in 15-20 minutes.