The main line, or mainlinein American English, of a railway is a track that is used for through trains or is the principal artery of the system[1][2][3] from which branch lines, yards, sidings, and spurs are connected. It generally refers to a route between towns,[4][5] as opposed to a route providing suburban or metro services. It may also be called a trunk line, for example the Grand Trunk Railway 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.[6] 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.
^"Kansas Railroad Terms". Kansas Department of Transportation. 8 January 2014. Retrieved April 17, 2019. Cites the following as its sources: Encarta 2000 Encyclopedia, The World Book Encyclopedia, UPRR-Railroad Terms, and Webster's New World Dictionary.
^"Glossary of Terms". Trains.com: World's Greatest Hobby. Waukesha, WI: Kalmbach Publishing. Archived from the original on August 6, 2020. Retrieved April 17, 2019.