Metropolitan line the top green light over a yellow light, and clear two green lights. The Metropolitan line's suburban rail character opposed to other London Underground lines is also shown by the long distances between stops. Eight of the top 10 furthest apart stations on the Underground are on the Metropolitan line. The section between Chalfont & Latimer and Chesham is the longest at , whilst the Finchley Road to Wembley Park section is the second longest, and Rickmansworth to Chorleywood the fourth longest overall. The Metropolitan line is the only London Underground line to operate an express service. Designed for commuters
Urban rail in the United Kingdom example Amersham and , but some stations much closer to the Greater London boundary, like and , are not in any zone. London has an integrated ticketing system via the Travelcard or Oyster Card for buses, Docklands Light Railway, suburban rail, tram, Underground and Overground. Unlike cities like Liverpool/Merseyside, Sydney and Paris, several operators provide suburban rail services. Most stations are served at least every 20 minutes, with many stations and routes having four, six or more trains per hour. c2c runs from London Fenchurch Street through east London via Basildon (or Grays and Tilbury) to Southend Central and Shoeburyness,