Funnily enough, I was talking about this with my sister last night.
When she was five and I was seven, I used to take her to school (well, we walked together, with me nominally in charge) about half a mile away. My mum was heavily pregnant and my brother was born the month after my sister started school.
My own children had a middle school system and changed schools at 9 after being at a primary where we took them to and from. The summer before, parents used to let them go to a sweet shop, then to Woolworth's, then to somewhere a bit further, until they learned to make the journey and cross the roads in time for starting school. They met up with friends at pre-arranged places on the way.
Once there, though, they were not allowed to leave until home time. I once locked myself in the sitting room (another story!) and rang the school to ask if my son (then 13) could come and let me out at break time, as he had a key. They wouldn't let him, even with my permission, which I thought was ridiculous, although I suppose they didn't know it was actually me on the phone. We lived maybe 10-15 minutes away.
I agree that they are disempowered these days, and also feel that parents can't win. People complain if they don't see children play outside, yet they worry when they are making regular journeys at times when lots of other children will be on the streets going in the same direction.