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
Central line (London Underground) GER on 1 May 1903. The line has three junctions: The line has the shortest escalator on the London Underground system, at Stratford (previously at Chancery Lane), with a rise of and at Stratford and Greenford the only stations where escalators take passengers up to the trains. That at Greenford was the last escalator with wooden treads on the system until it was replaced in March 2014. They were exempt from fire regulations because they were outside the tunnel system. The line has the shallowest Tube platforms on the system, at Redbridge, just below the road, and the sharpest curve,