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 the Mayor's Transport Strategy was published, which includes a proposal for this 'orbital' connection to Old Oak between Hounslow and Brent Cross. The London Mayor's Transport Strategy (MTS), published on 28 February 2018 and ratified by the London Assembly on 8 March 2018, includes plans for a West London Orbital railway line under Proposal 88. The mayor’s proposal for the service highlights that utilising new and existing orbital connections in west London could also improve public transport connections in the city centre. It reads: “Most Londoners want to move around London – rather than in and out of the centre