Transport for London (TfL) is a local government body responsible for most of the transport network in London, England. TfL has responsibility for various rail networks including the London Underground and Docklands Light Railway, as well as London's buses, taxis, principal road routes, cycling provision, trams and river services. It does not control all National Rail services in London, although it is responsible for London Overground and TfL Rail services. The underlying services are provided by a mixture of wholly owned subsidiary companies (principally London Underground), by private sector franchisees (the remaining rail services, trams and most buses) and by licensees (some buses, taxis and river services). TfL is also responsible, jointly with the national Department for Transport (