The Central line is a London Underground line that runs between West Ruislip or Ealing Broadway in the west, and Epping or Woodford via Hainault in the north-east, via the West End, the City, and the East End. Printed in red on the Tube map, the line serves 49 stations over 46 miles (74 km), making it the network's longest line. It is 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 traversing narrow tunnels, Central line trains are smaller than those on British main lines.
The line was opened as the Central London Railway in 1900, crossing central London on an east–west axis along the central shopping street of Oxford Street to the financial centre of the City of London. It was later extended to the western suburb of Ealing. In the 1930s, plans were created to expand the route into the new suburbs, taking over steam-hauled outer-suburban routes to the borders of London and beyond to the east. These projects were mostly realised after the Second World War, when construction stopped and the unused tunnels were used as air-raid shelters and factories. However, suburban growth was limited by the Metropolitan Green Belt: of the planned expansions one (to Denham, Buckinghamshire) was cut short and the eastern terminus of Ongar ultimately closed in 1994 due to low patronage; part of this section between Epping and Ongar later became the Epping Ongar Railway. The Central line has mostly been operated by automatic train operation since a major refurbishment in the 1990s, although all trains still carry drivers. Many of its stations are of historic interest, from turn-of-the-century Central London Railway buildings in west London to post-war modernist designs on the West Ruislip and Hainault branches, as well as Victorian-era Eastern Counties Railway and Great Eastern Railway buildings east of Stratford, from when the line to Epping was a rural branch line.
