An animation of touch ins and outs of Oyster Cards, London's travel smartcards, at tube and rail stations across a typical weekday in the city - best viewed in 720p.
The in/out numbers are for each 10-minute interval. For stations where the in/out numbers are roughly equal at that time, the colour is white. Red stations indicate a strong flow into the network and green stations show a predominately outward flow. The Oyster card data was supplied by Transport for London and a version of this animation was created and shown at the London Transport Museum during its "Sense and the City" exhibition in 2011/2. The video here is a screen capture of a OpenLayers map which was produced by me at UCL CASA for the exhibition. The background map is based on data from Ordnance Survey Open Data (Crown Copyright) and OpenStreetMap contributors (ODbL). Background imagery created using Mapnik.
May 2014 update: Added a cheesy soundtrack from the YouTube Audio Library: On the Bach by Jingle Punks.