> To refute this, one must show that the "critical mass theory" is not significant and that driver attentiveness to cyclists is not a function of the number of

> To refute this, one must show that the "critical mass theory" is not significant and that driver attentiveness to cyclists is not a function of the number of cyclists. Not quite. The critical mass theory could be real and significant, and ridership could drop from a helmet mandate, but the question is how it stacks against the reduction of head injuries from the helmet mandate