Railway goods traffic developed in the 1860s and 1870s, by which time almost every station had an associated goods yard. It then became possible to send goods from any station (or siding) in Britain to any other station. In particular, any station in the South of England could receive goods from places in northern parts. Places in the South were also able to order coal from collieries in Nottinghamshire, Derbyshire and Yorkshire, as well as other coalfields, to be conveyed to destination by rail. Such traffic had to cross London from North to South. There was also a certain amount of traffic in the opposite direction, as well as returned empty coal wagons.