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
London, Tilbury and Southend Railway London, Tilbury and Southend Railway The London, Tilbury and Southend Railway (LTSR), also known as Essex Thameside, is a commuter railway line on the British railway system which connects Fenchurch Street station in central London with destinations in east London and Essex, including , , , , Tilbury, Southend and . Its main users are commuters travelling to and from London, particularly the City of London which is served by Fenchurch Street, and areas in east London including the Docklands financial district via London Underground and Docklands Light Railway connections at and . The line is also heavily used by