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 Rail Rail Silverlink franchise in 2007. It has since taken on more services through a former London Underground line and over other network rail lines. London Rail lets a concession to operate the Overground. Operation is contracted to Arriva Rail London (owned by Arriva UK Trains) until 2024. London Trams is responsible only for the Croydon Tram known as Tramlink. Tramlink was set up in 2000 by a private finance initiative. It was bought by TfL in 2008 and is operated on its behalf by FirstGroup. London Trams has been working on proposals for other tram schemes in west and central