The growth of bike sharing is phenomenal. At last count, there were at least 500 schemes worldwide, from the largest (Paris, with 18,380 bikes), to many small schemes (for example, Civitavecchia, a town outside Rome, has just 40 bikes). More schemes are coming online all the time. Chicago, for example, launched its bike-share, called Divvy, this month.
To get a dynamic sense of bike-sharing around the world, take at a look at this tool from Oliver O’Brien, a university researcher from London. O’Brien has collected live data from 100 schemes, including most of the biggest ones. In the "global view," you can see which initiatives are most in use at any time. Then, you can zero in on a particular city and get a dock-by-dock snapshot. Using an animation feature, you can also relive the last 24 hours of activity, and speed up and slow down the frames as you like.
In total, the tool covers almost 10,000 docking stations, and more than 21,000 individual docks. Based on the first few weeks of comparison, the busiest bike schemes at the moment (by percentage of bikes used) are in Moscow, Rio, Mexico City, Taipei City, and New York City. Paris and Mexico City (3,408 bikes) generally have the greatest number of bikes in use at any one time.