I was brought up in the 70s/80s when it was the norm to play out on the street. Always in view of the house, (except for the odd trip to the sweet shop round the corner) and our road was fairly quiet.
As a result, I think it made us safer in a way as all the neighbours knew us, at least to see, even if they didn't have kids themselves. So if something had happened, a neighbour could say, ''oh yeah, I know that kid, she's one of the builder's kids, I saw her buying some Bazooka Joe when I went there for fags.'' And presumably if that same person saw us being hassled or approached they would know straight away something wasn't right.
I remember my sister going missing when she was about 3, (not for long, probably about 15 minutes all in.) The neighbours all knew her and were out looking for her straight away. One of them found her in the churchyard round the corner happily picking daisies. She was brought back just as the police arrived. Although thats an extreme example by todays standards, at least it shows how everu=yone knew all the kids.
I don't have kids but I'm happy for the neighbours kids to play in the street. I hardly know them to see and I think that can be dangerous in a way.