The higher frequency, which has increased capacity on the line 21%, has been made possible following the completion of a £1bn project to modernise the Victoria Line which included the installation by Invensys of Communications-Based Train Control (CBTC) with automatic train protection and automatic train operation, and a new fleet of 47 eight-car trains supplied by Bombardier.

TfL also says the reliability of the Victoria Line, which is used by around 200 million passengers a year, has improved during the last four years with delays cut by about one-third.

Further improvements to the Victoria Line are already underway with a £700m scheme to increase capacity at Victoria station. A new north ticket hall will open at the end of 2016, followed by completion of work to double the size of the existing south ticket hall in 2018.