Central line (London Underground) and Great Eastern Railway buildings east of , from when the line to Epping was a rural branch line. In terms of total passengers, the Central line is the busiest on the Underground. In 2011/12 over 260 million passenger journeys were recorded on the line. It currently operates the second-most frequent service on the network, with 34 trains per hour (tph) operating for half-an-hour in the westbound direction during the morning peak, and between 27 and 30 tph during the rest of the peak. This makes the Central line the busiest and most intensively-used railway line in the United Kingdom:
East London line line to the South London line with a terminus at , opened on 9 December 2012, creating an orbital railway around inner London. The East London Railway was created by the East London Railway Company, a consortium of six railway companies: the Great Eastern Railway (GER), the London, Brighton and South Coast Railway (LB&SCR), the London, Chatham and Dover Railway (LCDR), the South Eastern Railway (SER), the Metropolitan Railway, and the District Railway. The latter two operated what are now the Metropolitan, Circle, District and Hammersmith & City lines of the London Underground. The incorporation of the ELR took place