An abandoned railroad is a railway line which is no longer used for that purpose. Such lines may be disused railways, closed railways, former railway lines, even derelict railway lines. Some have had all their track and sleepers removed, and others have material remaining from the former use.
There are many hundreds of these throughout the world. Thousands of miles of railroads have been abandoned in the United States, much of it in the 40 years from 1965 to 2005. The right of way which has been established for such a line makes it useful for other transport, such as a rail trail. Other uses are possible. For example, in 1936, farmers in Aldrich, Missouri, found various uses for the land and materials of an abandoned railway. The abandoned railway stations on the line may be put to some other use too.
Many old lines have stopped making a profit. The decision to abandon a line may be taken by a railway company or by government, as with the Beeching cuts in Great Britain in the 1960s.
Railways specially built for mines or other industrial or logistical sites are abandoned if the mine is exhausted or the production ceases.
War can also lead to abandonment. In former Finnish Karelia, changes of borders due to World War 2 in 1945 led to several railways being abandoned or even demolished by their taker, the Soviet Union. A railway could become international, and without a border checkpoint, the line would become useless. Also, without connecting traffic, the traffic volume could be too low: evacuation of Finnish Karelia removed the Finnish population and international trade would not have been equally viable as domestic trade.
Bizarrely, Finland was obliged to keep the Laurila–Kelloselkä track open as a peace treaty article, although it was never used for international traffic, but only for local lumber transport. Before the war, the track ended in Kemijärvi, 270 km from the border, but the Soviet Union demanded Kemijärvi to be connected via rail to Soviet Kantalahti. However, when a metal thief stole 1.7 km of track in 2008, the government declared it was no longer required to maintain the track. It was last used in 2010.