Wendy Fonarow from the Guardian's Ask the Indie Professor says women face a "different set of challenges" when touring:
"The most fundamental one is that she is basically exiled in guyville, a female visitor to the boys' club (which as we know can be fun as a tourist, but hard as an ex-patriot). Masculine cultural norms are constantly displayed in vans, tour buses and venues. Thus, to avoid criticism, women keep the female stuff to themselves (I'm violating this principle right now). Female professionals are vigilant about not reinforcing gender stereotypes. This means women often conform their behaviour to masculine stereotypes and circumscribe "feminine" behaviour. If a female professional does anything that conforms to a female stereotype, she is pilloried. Take something as simple as preparing to go on stage. Western assumption is that attention to looks and presentation is a female characteristic. Therefore, a female artist's need or desire for some privacy and time to attend to her looks before going on stage is viewed as an irritant and liability. However, in some genres such as goth or death metal, male performers need and often take more time to put on makeup and clothing than their female counterparts. If the male artist does so, he is teased that he took longer to get ready than 'a girl'."
Not being a touring musician, I have nothing to add, but the lack of parity becomes really apparent on the production end, something that few people mention. Of all the shows I've been to in the past decade or so, I can count on one finger the number of times I've seen a woman as part of a road crew or working as a guitar tech.