We visited family in Europe earlier this summer. So much has changed there compared to only 10-15 years ago. We were never once worried for our kids wandering around alone, because streets were designed so drivers had to drive slow. Also no monster trucks and monster SUVs everywhere. Also lot's of segregated bikelanes. Lots of walkable neighborhoods. A lot fewer casual sociopaths, you know, the sort of people you see here driving on bald tires with their bumper ripped off, jagged pieces of metal sticking out from the front of their car.

Yes, kids brains are underdeveloped, but streets accommodate that there, it's not a death sentence.

It's absolutely unreal how far America seems to have fallen behind, compared to just 10-15 years ago, and how far ahead new traffic calming measures have gotten there in that same timeframe. That's the main thing that strikes us on our return. The absolute complete solipsism on this issue, how trashy and violent the public realm is here.

You obviously don't have kids. Even as 3/4 year olds they have great spatial skills when running, climbing, jumping. Better than most adults. They have less boundaries, that's for sure.

Nah. It's very kid dependent. Some kids that age have great physical skills, others not so much and don't develop until later.

It goes in spurts - right after a "growth spurt" the kid will be quite uncoordinated until their mind gets the hang of the suddenly larger body.