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
R25 (London) Gospel Oak to Barking Line and a provision for a stop at Renwick Road (if needed) and states that a further extension across the Thames should be provisioned. R25 (London) R25 is a possible railway orbital around the Zone 3 area of London, England. The proposed line would use some existing lines by National Rail and London Overground. Issue 755 of "Rail Magazine" (20 August 2014) says that the Mayor of London has started consulting on a new Zone 3 orbital railway, the 'R25'. The nickname alludes to the M25 orbital motorway. The idea featured in news media when the