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
London Underground 1986 Stock consultation results show that the blue prototype was the favoured, and provided the core design basis for the 1992 Stock that was built for London Underground's Central line and Network SouthEast's Waterloo & City line. London Underground 1986 Stock The London Underground 1986 Tube Stock consisted of three prototype electric multiple units built for London Underground that led to the development of the 1992 Stock. In 1984, London Transport ordered three different prototype trains to test new materials, construction methods and seating layouts. Two were built by Metro-Cammell at its Washwood Heath factory, and the third by British Rail Engineering