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 ticketing Tamil, Turkish and Urdu. Prior to 2009, some ticket machines were multilingual; they supported six languages and those machines had English, Spanish, French, German, Italian, and Japanese. The new languages were added as part of the Investment Programme of LU. London Underground ticketing The London Underground metro system of London, England uses a mix of paper and electronic smart-card ticketing. London Underground uses Transport for London's Travelcard zones to calculate fares, including fares on the Underground only. Travelcard Zone 1 is the most central, with a boundary just outside the Circle line and Travelcard Zone 6 is the most outlying