I guess it all depends on a lot of factors. When I was a kid I used to play on the street but there weren't that many cars and if there was a car passing by we'd clear the road.

I'm thinking that if it were a compound technically cars shouldn't be driving too fast, the headlights should be enough, plus there should be a couple of speed bumpers around so it should be OK. If you've assessed all factors and deemed it unsafe then I guess you should discourage kids from playing on the road.