Denver B-cycle launched on Earth Day 2010. During 2011, riders logged more than 431,817 miles, a nearly 97 percent increase over 2010, according to Denver Bike Sharing executive director Parry Burnap. The program debuted with roughly 400 bicycles scattered across 40 stations throughout the city’s downtown and key surrounding areas.

Since B-cycle’s debut in Denver, B-Cycle has expanded to numerous sites across the United States, including Boulder, Broward County, Chicago, Des Moines, Hawaii, Houston, Kansas City, Madison, Omaha, San Antonio, and Spartanburg.

The B-cycle website includes a tool that calculates the number of stations and bikes that would be needed for cities of a given size to implement bike-sharing. The tool also provides an estimate for the system’s emissions savings, vehicle miles saved, gallons of gas conserved, and calories burned (through exercise).