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 2009 Stock FICAS technology, giving a thinner bodyshell and hence (along with the larger size) more internal space for passengers. They are the first London Underground trains to be designed since the Rail Vehicle Accessibility Regulations were introduced, so they have more facilities for people with impaired mobility, including multi-purpose areas with tip-up seats and space for wheelchairs and pushchairs, and offset centre door poles for wheelchair access. The trains were the longest deep-level tube trains on the system when introduced, at , longer than the 1967 Stock. The more recently introduced sub-surface S Stock, which is also part of Bombardier's Movia