Jay Walljasper explains the notable increase:
"The pronounced rise of two-wheel and two-feet travel between 2010 and 2011 is attributable in part to an array of street improvements - including more bike lanes and special bicycle-and-pedestrian boulevards - installed around town in the past year as part of the Nonmotorized Transportation Pilot Project. The Twin Cities was one of four communities around the country designated as transportation laboratories in the legislation, which was passed by a Congress in 2005 and signed by President George W. Bush."
Walljasper also discusses the challenges inherent in trying to get an accurate count of cyclists.