Why Not in America?
Bogotá imported some Dutch engineers to redesign traffic flows and improve infrastructure. Cycling jumped ten-fold in two years.

Even Portland, Oregon, America’s bicycle commuting capital, is a relatively recent and somewhat unlikely success story. Neither the city’s density nor its weather suggests that it should have the highest cycling rates in the country. Nevertheless, policies designed to encourage riding have boosted cycle trips 400% since 1991.
(Via WorldChanging)