Central line (London Underground) Central line (London Underground) The Central line is a London Underground line that runs through central London, from , Essex, in the north-east to and in the west. Coloured red on the Tube map, the line serves 49 stations over , which makes it the longest Tube line. It is also one of only two lines on the Underground network to cross the Greater London boundary, the other being the Metropolitan line. One of London's deep-level railways, Central line trains are smaller than those on British main lines. The line was opened as the Central London Railway in 1900, crossing
Medium-capacity rail system requisite ridership due to network inadequacies (e.g. single-tracking) or changing demographics. In contrast with most light rail systems, an MCS usually (though not always) runs on a fully grade separated exclusive right-of-way. In some cases, the distance between stations is much longer than typically found on heavy rail networks. An MCS may also be suitable for branch line connections to another mode of a heavy-capacity transportation system, such as an airport or a main route of a metro network. The definition of a medium-capacity system varies due to its non-standardization. Inconsistencies in international definitions are even reflected within individual countries.