We probably all agree that freedom to play depends on the individual child, their family and the safety of the area they live in. The following is my personal experience. I am not recommending anything to anyone! That out of the way, here goes:
My 7-year old son has been playing out since he was four-and-a-half. At that time we lived in a minute terraced house with a 12 ft x 12 ft living room and virtually no garden. My very lively, gregarious son has no space to let off steam and it was difficult to invite his friends over for extended play times. Right outside our living room window was a small road. It was narrow, too, so any cars that came down it had to go quite slowly. Across the road was a piece of grass and a small playground. It was in full view of our house. Children aged about 5 upwards regularly played there, mostly without their parents, much to the interest, and later frustration, of my 4 year old son.
From the age of 3 or so,I began to take him to the playground regularly and by the time he was
four-and-a-half (one summer), he knew the children well, as I did. Most were OK, some I was less sure about.I began to stand some distance away for the playground, still within sight and monitoring things closely. I gave my son very clear boundaries regarding behaviour etc. If he did what he shouldn't do or went where he shouldn't go, he got grounded. As the months progressed, I began to stay in the house and not watch his every move. Along with his friends, he was allowed to play out on the pavement next to our house. He was allowed to take out his bike and rollar blades, keeping away from the roads. By the time he was 5 and a half, he was allowed to explore the small wood and football pitch, along with his trusted friends. Both these places were not within sight but a 2-minute walk away.
At this point I should say that we were friendly with a lot of our neighbours and so my son had a network of familiar people around him.
My son definitely benefited from this free time. It gave him his own space and allowed him to get more socially adept with his peers. I believe in unstructured play without constant adult supervision. I also think it was good for my son have lots of playtime that wasn't centered around expensive toys. (we quickly learned that toys he took out to show his friends risked being broken or fought over, so we allowed footballs but no beastwars models!)
However, I did worry. How could I not? There were scary moments, too, like the time some older boys persuaded my son (then 5) to go to our local off licence/shop and get them some sweets. He crossed a busy road by himself, walked in and asked the shopkeeper to give himn some sweets 'on tick'!!.
The shopkeeper knew him and us very well so they saw him safely back across the road and told us later. Needless to say he and his friends were severely told off and he was grounded for weeks.
It is hard to set rules. We made sure his friends always knew what rules we set our son, and what geographical boundaries we gave him so they would know if they were getting him into trouble. He always had to tell us if he wanted to play out of sight of the house, and get our premission.We drummed these rules into him daily. He was not allowed to cross roads without an adult watching. We told him the dangers: He was small so car drivers might not see him. Also we told him he was too young to judge speed and distances accurately. We read that it takes boys until 9 years of age to be able to do this. Girls can do it earlier. That might be a lot for a 5 year old to take on, but we wanted to instill a sense of danger in him. We also told him that he had a lot of freedom compared to many 5-year olds.
When he was approaching 6 we moved house.The move was partly prompted by our wish to give our son more safe playspace both indoors and outdoors. We deliberately chose and area where lots of children played out in the streets. I wouldn't have moved to a place that didn't offer this.
Again, once we had all got to know the children in in the neighbouring houses, he was allowed to play out. As he gets older, its gets easier to 'let go' of him. You never stop worrying, though. I was never cooped up inside and marshalled around outside as a child and I don't want my son to be either. He's never been a child who loves playing with his toys alone in his room.
But by the age of 5 he could ride a two-wheeled bike and rollar blade very proficiently.
Over a typical winter weekend, he plays out for about 4 hours,- longer in the summer. As always he regularly 'touches base' with us and we know where he is. He invites his friends back as well.
He is better behaved now, and more street-wise. There are lots of girls nearby and they act as a civilising influence. There's not much play-fighting now.
I don't think it has made him grow up more quickly, but perhaps a bit more differently, compared to some of his more home-bound friends. He's very fond of being outdoors, loves being in a group of children, prefering this to toys. It has definitely made him happy.
Sorry this is such a long note!