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
West London Orbital most modern standards". The transit time from Brent Cross to Surbiton was quoted as 28 minutes, with a maximum train speed of 80 km/h. The promoters cited a number of reasons why they believed an underground scheme would be cost-effective at £1.75bn: with lower tunnelling costs as the tunnel diameter would be smaller than for a heavy rail scheme; there are no other rail tunnels to avoid (as in central London); and the subsoil strata are suitable for modern tunnel boring machines (TBMs). A number of other notable orbital rail schemes for London have been previously proposed: West London Orbital