Hải Vân Tunnel

Road tunnel

The Hải Vân Tunnel, the longest tunnel in Southeast Asia and Vietnam at , lies on Highway 1 between the two cities of Da Nang and Huế in central Vietnam.

The Hải Vân Pass has long been recognised as a major bottleneck. The concept of a tunnel to bypass the long route over the top had long been sought.

Route planning and design work started in January 1998 by a joint venture between Nippon Koei Company Limited Japan and Louis Berger International Inc., USA with the Vietnamese Transport Engineering Design Incorporated (TEDI) providing consultation on the project.

The tunnel was split into two segments, a southern and a northern section. The southern section was constructed by a Vietnam–Japan joint venture between the Japanese Hazama Corporation and their Vietnamese partners, Cienco 6. The northern section was constructed by a joint venture between Korea's Dong Ah construction company and Vietnam's Song Da Construction Corporation. The tunnel officially opened on June 5, 2005. The main tunnel is wide. A second tunnel running alongside the main tunnel is currently used for maintenance and emergencies but it is planned to expand this at a later date as traffic increases. It is connected to the main tunnel by 15 cross tunnels. The tunnels have lighting, fire alarms, communication, water supply and treatment, ventilation fans, and radio broadcast systems. The tunnel subsequently has received an award for quality by the American Construction Management Association.