It deals with many things at once. First, is the quality of life sufficient for a 5-6 year old to have a sufficient allowance to spend some on a popsicle or other similar treat? Are the streets safe enough from a parents' perspective to walk around on their own, not likely to be kidnapped, literally, robbed (then again, who robs a 5 year old?)? Is there a low risk, subjectively and statistically, of getting hit by a car or other vehicle while doing so? Is there space to walk around, space to park a bicycle at both ends? Are there local corner stores, meaning that people do not have to go too far to get their basic needs? And are they close enough to allow a child to walk or bike there, while not so close that it's like a police officer lined pedway? And are parents going to feel no stigma or get ridiculed of child abuse, neglect or similar for letting their child do this?
When almost every parent, preferably 100% of them, are in the opinion that their own children can do this at this age, and are willing to let it be in practice, and making sure that it really is statistically safe, you know that you are in a community that is safe for all, from 8 to 80, and from birth to deathbed. We can have a place where children can roam freely, where parent's don't have to spend valuable time away from work to drive their kids home, where kids can play with friends whenever they want, when they can play at parks and playgrounds, and get exercise by walking or cycling, which feels intrinsically more useful than treadmills in that you are actually getting somewhere. If it's so easy a child can do it, I'm pretty sure that adults can do it just as well. Even the hungry stoner can get home/food safely, though not in the smartest way.
When did children lose this ability to roam like this? In 1900, the street was a place for everyone, streetcars, which weren't just big slow attractions in Fort Edmonton Park, horses, buggies, bicycles which yes many people rode everyday as their everyday means of transport and they had bicycles to match, they were even called freedom machines by suffragists, pedestrians and the few car drivers who in many cities had to have someone walking in front with a bright flag, and the car driver going at walking pace. And children could go where they wanted.
It began to change as cars became much more prevalent. Already in the 1920s the US was building parkways, in the 1930s Hitler began his massive program for autobahn construction, thousands of kilometres built in just a couple years (which goes to show that when a government wants something, they can usually get it done really quickly, and cycle paths are far easier to build than a freeway), the first unlimited speed limited section of freeway in the US opened in the 1940s, the US was thinking of a freeway network in the 1950s, and the interstate highway system was approved in the 1960s, and in the 1970s, traffic deaths peaked. Children had fewer and fewer places to safely walk, and pedestrians were treated as those who were just walking from the store to the parking lot or from the house or apartment to the garage. Pedestrian guardrails began to show up in a number of cities in the world. The stranger danger and the crackdown on drug crimes by imprisoning users happened in the 1980s, anyone remember the GI joe PSAs attached to the end of episodes (even though healthy human minds want to protect children, in the same way that you never want to disturb a bear mother with her cubs, you will be in for an eating competition with you as the food and the bears eating, there are some things to do, but keeping anyone younger than 12 with someone 12 or older at all times is not the solution).
It will take time to reverse this pattern of car domination and making people know that there are ways of reducing kidnapping without needing anyone younger than 12 to stay in the house, but if we never even start, how can we have a hope of having children being able to do this: (David Hembrow)