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 Borough of Croydon is linked into the national motorway network via the M23 and M25 orbital motorway. The M25 skirts the south of the borough, linking Croydon with other parts of London and the surrounding counties; the M23 branches from the M25 close to Coulsdon, linking the town with the south coast, Crawley, Reigate, and Gatwick Airport. The A23 connects the borough with the motorways. The A23 is the major trunk road through Croydon, linking it with central London, East Sussex, Horsham, and Littlehaven. The old London to Brighton road, passes through the west of the borough on Purley Way, bypassing the commercial