I have read that these women-only buses are found in Delhi, Bombay, Calcutta and Chennai. I think it's a great idea as well, we also have these women-only trains in here. And yes, I have ridden it countless of times. Even though it's still jam-packed, at least even if I get super close to someone, it's a woman and I won't be bothered as much. I don't ride the other side of the train anymore, even though it's both for men and women. Even if I'm with my boyfriend or my guy friends, I'd still separate from them and ride the train for women only.
With regards to men having their own bus, why not? I've read one article that sometimes, men board the women-only buses. In here, elderly men are allowed to ride the women-only trains, as long as they're above 65 years old and that's fine with me. Men should have their own buses to avoid the confusion that they have as to why it's only women who has their own buses.
Despite the harassing issues and equality issues, it's the only way to protect the women. Not all men cross the boundaries, that's for sure. But I've been a victim of harassment in public transportation already, so I do understand the need for separating both genders from each other. And maybe if men can have their own buses, they won't feel like there's an inequality happening.
However, if the authorities can be more strict and provide more security officers in the bus, then this could solve these issues and there would be no need for separation of both genders. I long for that day though, where we can feel safe anywhere we go, without the need to constantly protect ourselves or our belongings.