[jaccarmac]

I live in a suburb north of Dallas and on a short walk can see footpaths at the end of cul-de-sacs, former paths walled off with bushes, and former paths walled off with brick. The places where you can see the old sidewalk under the brick wall are particularly sad, I think. Speculatively, I agree with the people who have commented on the hostility to "undesirables". Here, I think road expansion is at play, too. As the streets these cul-de-sacs face become 4+ lane 45 MPH roads, the walls become necessary to manage road noise and walking down said road becomes more and more unpleasant. Notably, the brick walls are consistently and obviously low quality, and tend to fall apart until they eventually break at the bottom, sag, collapse, and are replaced. It's a pattern I only saw when I moved here (though I was never properly suburban before that).