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 began in 1973. The first section, between South Mimms and Potters Bar in Hertfordshire (junction 23 to junction 24) opened in September 1975 and was given the temporary general purpose road designation A1178 (a section of motorway-standard-road, originally the M16, which eventually was incorporated into the M25) was completed and operational before this. A Watford-avoiding route between the M1 and the A40 between north Watford and Denham was locally known as the Croxley Green/Rickmansworth bypass, and was operational about 1973/4; a section south of London (junction 6 to junction 8) opened in 1976. A section of Ringway 3 south of