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 Rail to Enfield Town, Cheshunt and Chingford and Romford to Upminster Line services on 31 May 2015. London Rail London Rail is a directorate of Transport for London (TfL), involved in the relationship with the National Rail network within Greater London, UK which manages TfL's non-London Underground train services. London Rail manages the London Overground (LO), London Trams and Docklands Light Railway (DLR). It will also be responsible for Crossrail. As part of an internal restructure within TfL, it recently merged with the (previously separate) London Underground directorate, bringing all of Greater London local transport services on rails under one division.