Historically, the problem was solved by not allowing women in public at all. In nearly all higher cultures, women lived in completely segregated and controlled world. Let's not forget that what is novel is not that a tiny minority of men are sex-obsessed low-inhibition asshats, but what is novel is that women casually sit in the bus right next to them. By this, of course, I do not intend to downplay the severity of some experiences some women make.