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
West London Orbital Line, Bakerloo Line, High Speed 2, Crossrail and the Piccadilly Line. It is anticipated the line will be operational by the mid-2020s, reflecting the fact that it makes use of existing under-used rail infrastructure rather than requiring significant lengths of new track or tunnels to be built. An unrelated scheme of the same name was previously proposed in June 2008 by the West London Business group. That proposal involved the construction of a new underground line across West and South West London and did not progress beyond concept stage. The West London Orbital line consists of a number of distinct