Central line (London Underground) that the transport benefits of a Park Royal station on the Central line are not sufficiently high to justify the costs of construction. 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,
TfL Rail and in Essex. That branch comprises the first 14 stations on the Great Eastern Main Line, with interchange at Shenfield for medium- and long-distance services beyond to East Anglia. In May 2018 TfL Rail also took over operation of the Heathrow Connect service between in central London and Heathrow Airport to the west (Heathrow Terminal 4 station being the terminus). That route has nine stations. The service is operated by MTR Corporation under contract to Transport for London (TfL). Between May 2016 and May 2017, TfL Rail carried over 47 million passengers on the Shenfield branch. In June 2013 TfL