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:
Central line (London Underground) and realigned and the stations lengthened, but it proved impossible to modify Wood Lane station to take 8-car trains and a new station at White City was authorised in 1938. The line was converted to the London Underground four-rail electrification system in 1940. The positive outer rail is higher than on other lines, because even after reconstruction work the tunnels are slightly smaller. Most of the tunnels for the extensions to the east of London had been built by 1940, but work slowed due to the outbreak of the Second World War until eventually suspended in June. The unused tunnels