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
M60 motorway unsigned Euroroutes E20 and E22. In 2008, the M60 was proposed as a cordon for congestion charging in Greater Manchester, although this was rejected in a referendum relating to the Greater Manchester Transport Innovation Fund. The M60 is the only true orbital motorway in the United Kingdom; the M25 motorway in London is not, due to the Dartford Crossing being designated the A282. The M60 was developed by connecting and consolidating the existing motorway sections of the M63, M62, and an extended M66. It came into existence as the M60 in 2000, with the completion of the eastern side (Junctions