By the numbers
70,000: The number of bicycles Wuhan, China, says are in its bike-share system, the largest in the world. In some Chinese cities, as much as half the population commutes by bike (in the Netherlands, it's 30%). The country also makes about two-thirds of the world's cycles.
$1,600: The average cost per year to maintain a shared bike. In New York City's setup, which makes its debut this summer (at 10,000 bikes, the largest program in North America), borrowing a bike will cost $95 a year; in London it is $70 a year; in Paris it's about $36.
$41 million: Amount paid by Citigroup to sponsor New York City's soon-to-launch 600-station service (called Citi Bike), which is being installed at no cost to taxpayers. In Europe many programs are run by advertising agencies such as Clear Channel Outdoor and JCDecaux.