London Underground with smaller trains that run in two circular tunnels ("tubes") with a diameter about . These lines have the exclusive use of a pair of tracks, except for the Piccadilly line, which shares track with the District line between Acton Town and Hanger Lane Junction and with the Metropolitan line between Rayners Lane and Uxbridge; and the Bakerloo line, which shares track with London Overground services north of Queen's Park. Fifty-five per cent of the system runs on the surface. There are of cut-and-cover tunnel and of tube tunnel. Many of the central London underground stations on deep-level tube routes
London Underground Park and Charing Cross stations, and including the first stations on the London Underground to have platform edge doors. Transport for London (TfL) was created in 2000 as the integrated body responsible for London's transport system. TfL is part of the Greater London Authority and is constituted as a statutory corporation regulated under local government finance rules. The TfL Board is appointed by the Mayor of London, who also sets the structure and level of public transport fares in London. The day-to-day running of the corporation is left to the Commissioner of Transport for London. TfL eventually replaced London Regional