Coloured dark blue, the Piccadilly line of the London Underground is the fourth busiest line on the network; it has 210 million passengers each year. It is mainly a deep level line, running from the north to west of London via zone 1. The line serves 53 stations of which 25 are below ground. It is the second longest line on the network after Central line, and it has the second most stations after District line.
Before becoming a line of the London underground, Piccadilly line began as the Great Northern, Piccadilly & Brompton Railway (GNP&BR), one of several railways controlled by the Underground Electric Railways Company of London. On 1 July 1910, the GNP&BR was merged with the Backer Street and Waterloo Railway, the Charing Cross, Euston and Hampstead Railway by private Act of Parliament, to become the London Electric Railway Company. The Piccadilly Circus Station was rebuilt and opened on 10 December 1928. The new station included a sub-surface booking hall and eleven escalators. During the 1930’s the Piccadilly line was extended north to Cockfosters as well as west to Uxbridge.
In 1975 the Heathrow extension was added on the the Piccadilly line. During the planning stages of the Victoria line, a proposal was put forward to transfer Manor House station to the Victoria line, and also to build new “direct” tunnels from Finsbury Park to Turnpike Lane station, thereby cutting the journey time in and out of central London. This idea was eventually shelved due to the inconvenience to passengers that would have been caused during rebuilding, as well as the costs of the new tunnels. Even so, the Piccadilly line was still affected at Finsbury Park by the construction of the Victoria line. The westbound service was redirected through new tunnels, to give cross-platform interchange with the Victoria line on the platforms previously used by the Northern City Line. This work was completed in 1965, and the diversion came into use on 3 October 1965, three years before the opening of the first stage of the Victoria line.
210.169 million (2011/12) passenger journeys