Non-revenue track
Non-revenue track, or a non-revenue route, is a section of track or transport route that is not used to carry passengers or revenue-earning freight or goods. The term is used to refer mainly to sections of track or routes in public transport systems, such as rapid transit and tramway networks, but non-revenue track or routes can also be found in other transport systems. Non-revenue tracks may be used for revenue service during temporary reroutings.