If we're talking commuting:

Workplace grooming/dressing standards, whether by company policy or social norm, tend to be higher for women than for men. (Judging by what I've seen, anyway.) I can imagine that it's a little daunting to figure out exactly how to make yourself look presentable (or bring clothes and shoes with you) and be not-stinky when you get to work, unless you work somewhere relatively casual or have access to showers, etc. I'm not afraid to sweat (I sweat like a pig), and I'm not terribly "fussy" about my appearance (I don't wear makeup, for example), but I don't want to go to the grocery store like that, let alone work!