The New York Times has a piece about women cycling, and their perception of safety. It is suggested that a high proportion of women cycling for everyday transport is one of the best indicators of how safe the road environment is for vulnerable road users.
This is disputed in this article by Elly Blue, who argues that the low participation rates of women cycling commuters is due to economic factors and gender disadvanteges.
I go for the safety argument…..
Note Sydney cycling participation hugging the left frame ….