According to data from the U.S. Census Bureau's 2012 American Community Survey (ACS), 0.64 percent of all commute trips were made by bicycle nationwide.  This represents an increase of approximately 9.6 percent from 2011, and is the largest year-on-year increase since the economic crisis began in 2007-08.  These estimates continue a longer-term trend -- since 2000, ACS data indicate a 61.6 percent increase in bicycle commuting.

Read more about ACS data on bicycle commuting at the League of American Bicyclists webpage.  Note that, among the nation's 70 largest cities, the City of Chicago increased its bicycle commute share by 459.7 percent between 1990 and 2012, more than any other city except Detroit.