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
History of the London Underground were first installed at Earl's Court between the District and Piccadilly line platforms, and at all deep level tube stations after 1912. The last, the Charing Cross, Euston & Hampstead (the Hampstead) opened in 1907, and ran from to Camden Town, before splitting into two branches going to Golders Green and Highgate (now Archway). To promote travel by the underground railways in London a joint marketing arrangement was agreed that included maps, joint publicity and through ticketing. UD signs were used outside stations in Central London. The UERL acquired London bus and tram companies in 1912 and the following year