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 ticket has been resold can be a difficult and time-consuming process. In an attempt to reduce the numbers of Travelcards being used by more than one person, an experiment took place at Brixton station in 2002. A box was provided at the station exit into which passengers were encouraged to deposit Travelcards that were no longer required, and for each ticket deposited London Underground made a small donation to local charities for the homeless. London Underground ticket machines in all stations support the following 17 languages: English, Spanish, French, German, Italian, Japanese, Arabic, Bengali, Chinese, Greek, Gujarati, Hindi, Polish, Punjabi,