My friend's dad was a builder. When I went out with him and his parents, his mum used to sit in the cab of his dad's pick-up truck and friend and I would sit on cushions in the open back.
We were too poor to have a car, but my DF got the opportunity to buy a motorbike and sidecar at an absolute bargain price. The idea was that he and DM would go on the motorbike and me and the dog, a German Shepherd, would go in the sidecar. DM hated being on the back of the bike, so we ended up with her and the dog in the sidecar and 4YO me on the back of the motorbike. No crash helmet either, they weren't compulsory until the early 70s iirc.
DF got another motorbike when the first one gave up the ghost and for the last 2 terms of primary after we moved, I used to get a lift to school on the back of it, rain or shine, no helmet or protective clothing.
At 6 or 7, I was allowed to "camp out" alone in the garden all night in fine weather, with an improvised tent that was actually a clothes airer on its side with a tablecloth over it. Sometimes I had the dog for company.
At 10, I used to walk about a mile and a half, across a busy main road and a park, to my friend's house. We'd take a packed lunch and get a bus to some woods and open countryside a few miles away and play there all day, then get the bus home at teatime. No adult supervision whatsoever.
We also used to play in big derelict houses that were waiting to be redeveloped, and on building sites at the weekends when the builders weren't working. Building sites were rarely fenced off in the early '60s.
The thing that I was allowed to do that still gives me heebies was going down the hill by the flats where we lived on my roller skates. The hill got steeper as you went down it, so you went faster and faster, and there was a reflex angle at the bottom where, if you didn't make the turn, you'd go down the kerb and probably land on your face in the road.
DM told me years later that it used to worry her so much that she'd hold her breath when she heard me stomping up the hill, and not breathe out till she heard me round the corner safely at the bottom. I asked why she didn't make me stop, and she just said "You always did just what you wanted no matter what I said, so there wasn't any point".
I went back a few years ago, when DP and I were in the area, and it looked pretty hairy. DP was shocked that I had the nerve to do it. I must have been fearless when I was a kid.