London Underground 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. Of the 32 London boroughs, six (Bexley, Bromley, Croydon, Kingston, Lewisham and Sutton) are not served by the Underground network, while Hackney has Old Street and Manor House only just inside its boundaries. Lewisham used to be served by the East London line (stations at New Cross and New Cross Gate). The line and the stations were transferred to the London Overground network in 2010. London
M25 motorway are in Buckinghamshire, 17–25 are in Hertfordshire, and 26–31 are in Essex. Policing of the road is carried out by an integrated policing group made up of the Metropolitan, Thames Valley, Essex, Kent, Hertfordshire and Surrey forces. The M25 is one of Europe's busiest motorways. In 2003, a maximum of 196,000 vehicles a day were recorded on the motorway just south of London Heathrow Airport between junctions 13 and 14. The idea of an orbital road around London was first proposed early in the 20th century. An outer orbital road around London had first been proposed in 1913, and was