John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.
Jo Wood's map of five million British bike rides looks like it came from outer space.
What is this thing, a new species of bioluminescent blob dredged up from the Mariana Trench?
Actually, it's us – a visualization of how humans travel by bicycle around central London. The entrancing video was created by Jo Wood, a professor of visual analytics at City University who writes papers with names like "Interactive visual exploration of a large spatio-temporal dataset: Reflections on a geovisualization mashup." Clearly, he knows his stuff.
Wood's animation shows a year of rides among users of the bike-sharing program Barclays Cycle Hire. The program today involves 570 stations and about 8,000 bikes, so Wood's data set was huge, encompassing some 5 million journeys that occurred in the year after Barclays launched in 2010.
The model starts at a point where scads of bike users are skedaddling around willy-nilly like radium-doused ants. But the frenzied orgy of pedaling soon transforms into a more minimal network of strong, glowing loops. The professor explains the reason for the metamorphosis:
Origins and destinations of each journey recorded and animated along a curved trajectory. This animation shows the effect of changing the length of the 'trail' left by each journey (starts to increase from 15 seconds into the animation).
By changing the prominence given to more common journeys (from 45 seconds onwards), structure emerges from the apparent chaos of journeys. Three major systems become apparent (from 1 minute onwards) - Hyde park to the west, commuting to/from King's Cross St Pancras to the north and Waterloo to/from the City to the east.
Like that visualization of a full day of airline routes, the way people travel by bike en masse is oddly beautiful. Practical, too: According to Douglas Heaven at New Scientist, who talked with a colleague of Wood's, the researchers next hope to add anonymous data on individual users, which would "lead to better placement of new docking stations and help balance load across the network."