The tunnel presents the major north-south connection in Afghanistan, cutting travel from 72 hours to 10 hours and saving about 300 km. It reaches an altitude of about 3.400 m and is 2.6 km long. The width and height of the tunnel tube are 7 m. About 1.000 vehicles pass through the tunnel daily.

In 1955 Afhghanistan and the Soviet Union signed an agreement that initiated the development of the Salang road. Built with Soviet help the tunnel was opened in 1964 and provided a year-round connection from the North and the Soviet Union to Kabul. During the Soviet-Afghan war, the tunnel was a crucial military link to the South yet prone to ambushes by the mujaheddin. On November 3, 1982 the Salang tunnel fire killed an estimated 176 people when, apparently after a collision, a tanker truck blew up in the tunnel and the fire engulfed a military convoy. After the Soviets retreated, maintenance suffered, and eventually, in the course of combat between the Northern Alliance and the Taliban in 1997-1998, the tunnel's entrances and ventilation system were destroyed, so that it could only be crossed by foot. After the defeat of the Taliban, a joint effort between agencies from Afghanistan, the United States, and Russia cleared the mines and debris and reopened the tunnel on January 19, 2002.