we lived in a house with a fenced yard front and back. They played outside 3 seasons of the year from the time they could walk. Once they were about 3 I didn't feel like I had to supervise them every minute. We lived on a quiet one-block street with basically no traffic, so from the age of 4 or so they could run up and down with playmates even though there were no sidewalks. They knew not to go into anyone's house without asking me for permission first, and whose houses were off limits (adults with no kids). They also knew not to go off the block.
They couldn't walk to their elementary school because it was over a mile away and through a questionable neighborhood (it wasn't that it was a housing project, it was a few of the people who lived on that street) and past the high school, also two very busy intersections. I also didn't let my son walk to the high school. Other son went to high school across town. And unfortunately there were no grocery stores nearby.
When we moved they were teenagers. We bought a house in a more or less self-contained subdivision that had just a couple of entry points off a busy highway. In retrospect I would not do that again, but there we are. Nobody could walk anywhere. Son was driving, so he drove to school. Daughter rode a van and was picked up at a point nearby; I dropped her off. Other son was dropped off by his dad. But there was a convenience store just up the highway and I let the kids walk up there. Now my daughter lives in that house and the neighborhood has changed. There are more kids, and some play outside the way mine did growing up. There's a Dollar General Store at the bottom of the subdivision (ugh) and some kids are sent down there walking or on their bikes to pick up stuff for mom, or they go to get cold sodas and snacks for themselves. It's a little more like a neighborhood than it was.
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