This is a screenshot of a heatmap of runs carried out in central London, using the Nike+ training “app” which utilises a phone’s built-in GPS to record the route. Many runs are aggregated and then combined into this heatmap, which is overlaid on the regular Google Maps...

People often say “I waited ages for a bus and then they all turned up at once”. As the map above shows if all the timetabled buses in London literally did show up at the same time you would be stuck in an impressive traffic jam. It represents the 114 thousand or so bus trips that...