Over here (Finland), it is very common that a road is cul-de-sac for motor vehicles but you can get through riding bike or on foot.
This is common in USA if the cul-de-sac is a retrofit to a previously-through road. (If not by design, then in the breach, because someone has knocked a hole in the fence and it hasn't been fixed.) However, in the sorts of housing-only developments that have culs-de-sac designed in, the typical cul-de-sac is completely surrounded by houses with yards backed by other houses with yards, so there's nowhere to go.
Personally, I've never lived in such an environment, and when I've visited those who do it has driven me to distraction. You can't get anywhere directly! My impression is that this sort of development design is growing less popular, although maybe it's just that I more rarely visit people who live in such places.
Right, so the point is that property owners do not want to have anyone walk by on foot, because they fear they could be trespassers or loiterers that are not welcome in the area? And this is why a cul-de-sac stops not only cars but everything, with a fence.
But then that also stops e.g. children from moving about on their own in the neighbourhood.
This is common in USA if the cul-de-sac is a retrofit to a previously-through road. (If not by design, then in the breach, because someone has knocked a hole in the fence and it hasn't been fixed.) However, in the sorts of housing-only developments that have culs-de-sac designed in, the typical cul-de-sac is completely surrounded by houses with yards backed by other houses with yards, so there's nowhere to go.
Personally, I've never lived in such an environment, and when I've visited those who do it has driven me to distraction. You can't get anywhere directly! My impression is that this sort of development design is growing less popular, although maybe it's just that I more rarely visit people who live in such places.