Where do the children play?

> Consider some statistics on the American childhood, drawn from children aged 8-12: 62% have not walked/biked somewhere (a store, park, school) without an adult

This is really not representative for other Western countries. Where I'm from, I would say that 75% of 6 year olds walk/bike to school alone, and 100% of older kids do.

> In physical space, Western children are almost comically sheltered.

I think the author should stick with "kids in the USA" when he means that.

I think a lot of this simply depends on the distance between home and school (or other places kids need to go to) – so it's the difference between a compact city and sprawling suburbs.

Where I live (central Europe), the density of public elementary schools in cities is high, so kids walk there alone. The density of secondary schools is lower, so most kids use bicycles or trams / buses.

Interestingly, there are a few private elementary schools (usually english speaking) for children of expats, where cars queue up in the morning, while parents drop off their children. I've never seen this at public schools. I believe this is because there are only a handful of those schools, so they are further apart – and maybe also because the parents (growing up in the US or UK) are already conditioned that this is a normal thing to do.