Anecdotal:  I don't ride a bike anywhere, though as a youth I rode my bike everywhere, constantly.  Today the roads are just too unsafe for bikers, helmeted or not, in the places I've been in the USA.  The biggest exception was Madison, Wisconsin, in my experience.  But there's nowhere else I've been where I would feel safe for one minute actually using a bicycle for transportation.

Karen in Austin

'tis strange I should be old and neither wise nor valiant. From "The Maid's Tragedy" by Beaumont & Fletcher