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 including by Modern Railways magazine and the independent blogging community A number of routes have previously been examined for new orbital tube lines and improved connectivity across West and North London. It was considered that the most likely route of the previous proposal would be a north-south route running from Brent Cross to Surbiton, via Wembley Park, Ealing Broadway, Richmond and Kingston fully underground, connecting several London Underground and National Rail lines, including the forthcoming Crossrail 1 at Ealing Broadway. The proposal envisaged an underground driverless light rail train system similar to the Docklands Light Railway, and updated "to the