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
Timeline of the London Underground eventually consolidating under the single ownership of the Underground Electric Railways Company of London (UERL), with lines stretching across London. In 1933, the UK Government amalgamated the UERL and the Metropolitan Railway as a single organisation, named the London Passenger Transport Board. The London Underground has since passed through a series of administrations, expanding further by the construction of new extensions and through the acquisition of existing main line routes, culminating in its current form as part of Transport for London, the capital's current transport administration, controlled by the Greater London Authority. This timeline lists significant dates in the history