It is a single-track metre gauge line connecting the capital Hanoi in the north to Ho Chi Minh City in the south, for a total length of 1,726 km (1,072 mi).

In 2024, Lonely Planet named the Reunification Express "one of Southeast Asia’s best-loved railways – and one of the most epic overnight train journeys in the world.

"[7] For the most part, this 1,726 km (1,072 mi) long metre gauge line follows the coastline of Vietnam, beginning in Ha Noi, passing through the provinces of Hà Nam, Nam Định, Ninh Bình, Thanh Hóa, Nghệ An (Vinh), Hà Tĩnh, Quảng Bình (Đồng Hới), Quảng Trị (Đông Hà), Huế, Da Nang, Quảng Nam, Quảng Ngãi, Bình Định, Phú Yên, Khánh Hòa (Nha Trang), Ninh Thuận, Bình Thuận (Phan Thiết), Đồng Nai and Binh Dương, before coming to an end in Ho Chi Minh City.

[9] Passengers arriving in Hanoi are able to transfer to several other railway lines, leading to Haiphong, Hạ Long Bay, Thái Nguyên, Lào Cai, Lạng Sơn and the People's Republic of China.

[5] In response, the French began using the armed armoured train La Rafale as both a cargo-carrier and a mobile surveillance unit.

[5] The U.S. Army operating in South Vietnam had considerable interest in the North–South line because of the potential it offered in the bulk movement of cargo at low rates.

The system was used to support the Military Assistance Command, Vietnam, construction program and transported hundreds of thousands of tons of rock and gravel to air base and highway sites.

The bridge was eventually destroyed by laser-guided smart bombs during separate raids on 27 April and 13 May 1972, as part of Operation Linebacker.

After the Fall of Saigon on 30 April 1975, the Communist government of the newly unified Vietnam took control of the former South Vietnamese railway.

Heavily damaged, the war-torn North–South railway line was nevertheless restored and returned to service on 31 December 1976, promoted as a symbol of Vietnamese unity.

On 7 August 2023, rocks collapsed at km 455 in Quang Binh in a tunnel, leading to massive delays (up to 16 hours 26 minutes).

More recently, rehabilitation projects sustained by official development assistance have allowed some of the most critical pieces of infrastructure along the line to be replaced, although much work still remains to be done.

For instance, heavy rains falling on Vietnam's north central coast in October 2010 swept away several sections of track in Hà Tĩnh and Quảng Bình provinces; the flooding of many of the nearby provincial roads, which remained several metres underwater, prevented repair crews from reaching the affected sections for weeks.

[8] According to a joint Japanese-Vietnamese evaluation team, the recent installation of additional auto-signal systems at key crossings along the line has contributed to a decline in railway accidents.

A researcher from Villanova University noted "There are numerous safety issues with level crossings...usually, an accident occurs every day.

"[36] Many rail bridges and tunnels have suffered deterioration since the 1970s, requiring trains passing over or through them to reduce speeds as low as 15 kilometres per hour (9.3 mph).

[2] In addition, the center of the country is subject to violent annual flooding and bridges are often swept away, causing lengthy closures.

These measures include: public awareness campaigns on railway safety in the media; construction of fences and safety barriers at critical level crossings in major cities; mobilization of volunteers for traffic control at train stations and level crossings, especially during holiday seasons; the installation of additional auto-signal systems; and the construction of flyovers and underpasses to redirect traffic.

Rail transport only became a national priority for the Vietnamese government around the mid-1990s, at which point most of the railway network was severely degraded, having received only temporary repair from damages suffered during decades of war.

Funding of the $56 billion line would mainly come from the Vietnamese government; reports suggest Japanese development aid could be made available in stages, conditioned on the adoption of Shinkansen technology.

[43] This article incorporates public domain material from websites or documents of the United States Army Center of Military History.