London Underground infrastructure Tube Programme, investigating replacing the trains for the Bakerloo and Piccadilly lines, is looking for trains with better energy conservation and regenerative braking. The Underground serves 270 stations. Fourteen Underground stations are outside Greater London, of which five (Amersham, Chalfont & Latimer, Chesham, and Chorleywood on the Metropolitan line and Epping on the Central line) are beyond the M25 London orbital motorway. The longest distance between two stations is between Chalfont & Latimer and Chesham on the Metropolitan line. The shortest distance between adjacent stations is the between Leicester Square and Covent Garden on the Piccadilly line. The station furthest
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