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 Borough of Sutton provided by Govia Thameslink Railway under the Southern and Thameslink brands. A sizeable bus infrastructure which is part of the London Buses network operates from a main hub on the Sutton one-way system. Services are operated under contract by Abellio London, London General, London United, Metrobus and Quality Line. Route X26 is the longest route in London, operating from Croydon to Heathrow Airport via Kingston. Sutton is linked into the national motorway network via the A217 and M25 orbital motorway at Junction 8. The M25 skirts the south of the borough, linking Sutton with other parts of London and the