London, UK: Time lapse sequence of anonymous underground passengers in station concourse, passing through the ticket barriers, getting off the escalator and along tunnels.

London, United Kingdom: London Underground tube (Victoria Line)train arriving at station platform and the train doors opening and passengers alighting.

Germany: Commuters squeeze into an overcrowded yellow underground train. Camera pulls out as the doors close and the train drives away.

London, England: Worker putting up a poster on the opposite side of the track next to the underground station platform

London, England: Close up shot of London Underground sign with scaffolding in the background, wide view of people walking down steps to enter underground station.

London, England: London Underground workers fitting new piece of rail track, welding track

London, England: Time-lapse footage of commuters walking at Victoria Underground Station.

Paris, France: Camera pans down from wrought-iron sign for Saint Michel Metro underground train station saying 'Metropolitan' in the Art Nouveau style, to show people walking up steps out of metro station

Paris, France: General view of entrance to Metro underground train for Saint-Michel with Art Nouveau sign over subway entrance seen in shadow

London, England: London Underground workers gathered on station platform being briefed by chief

London, England: Underground rail engineers at work in tunnel (wearing high-vis jackets and hardhats), pushing equipment along tracks

London, United Kingdom: train from London Underground arriving at station, interior of train carriage with commuters sitting down.

London, UK: Various low angle shots of Big Ben clock tower including one with 'Underground' sign in foreground

London, England: Metronet engineers (wearing orange work overalls) gathered on station platform at end of shift, signing time sheets

London, England: Workers repairing rail track inside tunnel

London, England: Workers laying concrete round bolted section of rail track

Paris, France: General view of wrought-iron Art Nouveau entrance to M�ƒ©tro Boissi�ƒ¨re on tree-lined Hector Guimard street with two people wearing bags talking in foreground

Entrance to a subway station in Times Square, Manhattan New York City, USA. Sign reads; 'Times Square 42 Street Station'.

London, England: Various interior shots of Kings Cross St Pancras tube station including empty ticket hall, wayfinding signage and ticket barriers.

Surrey, England: Various shots of tunnel construction including a digger breaking through the tunnel wall and shifting rubble with large prodding instrument.