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 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