The main line or mainline (American English) of a railway 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. 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.
Railway points (railroad switches in the 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 disaster in the US.
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.
In the UK, the term "main line" may also be used to distinguish any train or track that is not part of a light-rail or underground network.
Famous quotes containing the words main and/or line:
“Of all wit’s uses, the main one
Is to live well with who has none.”
—Ralph Waldo Emerson (1803–1882)
“Our job is now clear. All Americans must be prepared to make, on a 24 hour schedule, every war weapon possible and the war factory line will use men and materials which will bring, the war effort to every man, woman, and child in America. All one hundred thirty million of us will be needed to answer the sunrise stealth of the Sabbath Day Assassins.”
—Lyndon Baines Johnson (1908–1973)