Central line (London Underground) Hammersmith (Grove Road) railway station. Authorisation was granted in 1920, but the connection was never built, and the L&SWR tracks were used by the Piccadilly line when it was extended west of Hammersmith in 1932. On 1 July 1933, the Central London Railway and other transport companies in the London area were amalgamated to form the London Passenger Transport Board, generally known as London Transport. The railway was known as the "Central London Line", becoming the "Central line" in 1937. The 1935–40 New Works Programme included a major expansion of the line. To the west new tracks were to be
London a major international air transport hub with the busiest city airspace in the world. Eight airports use the word "London" in their name, but most traffic passes through six of these. Additionally, various other airports also serve London, catering primarily to general aviation flights. The London Underground, commonly referred to as the Tube, is the oldest and third longest metro system in the world. The system serves 270 stations and was formed from several private companies, including the world's first underground electric line, the City and South London Railway. It dates from 1863. Over four million journeys are made every