When the countryside is flat and good infrastructure exists at the same time, the winter is not that big issue. It's not ideal, but it's not stopping most of the people either. For example people in Sweden have no problem with it: http://www.copenhagenize.com/2010/12/winter-cycling-in-umea-... The issues of winter cycling are quite small compared to issues accociated with changing the cycling culture and building the infrastructure. So I suppose if Americans made their "flat enough cities" bike friendly, they would cycle even during winter, as other nations with good cycling conditions do.