The main line, or mainline in American English, of a

railway Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

is a track that is used for through trains or is the principal artery of the system from which branch lines, yards, sidings, and spurs are connected. It generally refers to a route between towns, as opposed to a route providing suburban or metro services. It may also be called a trunk line, for example the

Grand Trunk Railway The Grand Trunk Railway (; ) was a Rail transport, railway system that operated in the Provinces and territories of Canada, Canadian provinces of Quebec and Ontario and in the List of states and territories of the United States, American sta ...

in Canada, or the Trunk Line in Norway. For capacity reasons, main lines in many countries have at least a double track and often contain multiple parallel tracks. Main line tracks are typically operated at higher speeds than branch lines and are generally built and maintained to a higher standard than yards and branch lines. Main lines may also be operated under shared access by a number of railway companies, with sidings and branches operated by private companies or single railway companies. Railway points (UK) or switches (US) are usually set in the direction of the main line by default. Failure to do so has been a factor in several fatal railway accidents, for example the Buttevant Rail Disaster in Ireland, and the Graniteville train crash in the US.

References

Rail transport operations Railway line types {{Rail-transport-stub