Oh dear!
I think there's probably some information missing here. I looked on Google and the hebrew posters were probably put up before a special event, maybe a new Torah scroll, or a funeral, or a wedding, when there are hundreds, even thousands, of Jews milling around. Roads are closed to traffic (with police permission) and for safety for women and girls they should keep out of the way. There was a huge funeral recently for a highly respected Jewish lady.
So someone forgot to take them down. Normally there's no need for people to walk on different sides of the road.
We lived in a very orthodox area for some time, these events are very lively.
But not to deny that the roles of men and women are clearly defined.