48 Madcap Hours in the Life of Citi Bike

Someone in New York City hops on a Citi Bike; within minutes they could be blocks away in any random direction. But pile thousands of such rides together, and patterns in the country's largest bike-sharing system leap out.

That much is evident in an entrancing visualization of Citi Bike usage over two fair-weather days last September. Created by Jeff Ferzoco and the folks at the Rudin Center for Transportation and the Spatial Information Design Lab, the model shows roughly 75,000 rides from station of pick-up to drop-off. (They're displayed as point-to-point journeys; the street grid perhaps will enter the equation in the next version.) The rides are helpfully color-coded to show the types of Citi Bike riders, with blue for annual members and yellow for casual ones.