We need to make a clear distinction here between crime rates in general and crimes where a child is involved and the perpetrator(s) and strangers.
As far as I'm aware the biggest dangers to children are their cohabitating relatives followed closely by non-resident family and friends.
The solution to this issue for me was to move away from the big city I was in to a much smaller one, where the kids next door and a few houses down play in the street and my neighbors talk to me.
Yeah, kids walk more when adults walk more. It makes sense: more pedestrian infrastructure, and people are more used to pedestrians. When drivers aren't used to pedestrians, they don't look for them.
A lot of places in the US people are wary of adult pedestrians. They see someone walking and assume something is wrong--a car broke down, or the pedestrian is somehow up to no good. If people have the attitude that walking is weird and a cause for alarm, they won't want their kids doing it.
Plus, in lots of suburban areas, there's nowhere for kids to walk to. Wooded areas, if they exist, generally belong to somebody who doesn't want strangers messing around on their land. If there are Main Street shops, that could work, but a lot of Main Streets now are either pawn shops and check cashing outlets or high end restaurants and boutiques, with nothing really there for kids. And it seems less pleasant to send kids to a corporate store like CVS than to a mom and pop business.
I also think there are fewer kids in lots of suburban neighborhoods than there used to be, with family sizes shrinking and fewer retirees leaving the neighborhoods where they raised their kids. And kids seem to form cliques around interests earlier and earlier, which means their friends could be halfway across town. Adults don't automatically hang out with their neighbors much anymore, and neither do kids.
I bet if there exists statistics on how much time children spend alone outside you will see it decrease as car use increase.
Cars are my biggest fear when the kids go outside alone. Soon the oldest will begin school and I want her to go by her self, but the amount of cars on the road is scary. Especially around the school it's mayhem caused by parents driving their kids 400 meters to school.
