Branch line

The '0 kilometre peg' marks the start of a branch line in Western Australia.
A branch line is a secondary railway line. It links to a more important route, usually a main line. A very short branch line may be called a spur line. David Blyth Hanna, the first president of the Canadian National Railway, said that although most branch lines cannot pay for themselves, they are essential to make main lines pay.[1][2]
Branch Line Media
Railway connection between the new Nuremberg–Munich high-speed railway and Germany's historical rail network.