After two months on the street, New York's first bike-sharing program Citi Bike is starting to yield some interesting data about how riders are actually using the service. Citi Bike has made this kind of data surprisingly transparent — it's simple to see real-time information on where bikes are available – but the New Yorker went one step further, measuring usage at fifteen-minute intervals from June 8th through July 8th and plotting it on an interactive map.

On the surface it might just look like a bunch of pulsating bubbles, but upon looking further you can see the city come alive: a herd of commuters traveling south to the Financial District, or meandering weekend journeys, or a westward trek just before the July 4th fireworks on the Hudson river.