Central line (London Underground) interchange, it was ruled out on grounds of cost, the disruption it would cause to the Central line while being built and because the platforms would be too close to sidings at Liverpool Street and would not be developed until after Crossrail is fully operational. The developers of the "First Central" business park at Park Royal, west London, were planning a new station between North Acton and Hanger Lane. This would have served the business park and provided a walking distance interchange with Park Royal station on the Piccadilly line. This is not being actively pursued; London Underground has said
Circle line (London Underground) the stations are shared with one or more of the three other sub-surface lines, namely the District, Hammersmith & City and Metropolitan lines. On the Circle and Hammersmith & City lines combined, over 114 million passenger journeys were recorded in 2011/12. The first section became operational in 1863 when the Metropolitan Railway opened the world's first underground line between Paddington and with wooden carriages and steam locomotives. The same year a select committee report recommended an "inner circle" of lines connecting the London railway termini, and the Metropolitan District Railway (commonly known as the District Railway) was formed to build