Totally depends on the particular kid, the group of friends they run with and the area you live in. We live in a small town and I've raised my kids to not be irresponsible or disrespectful little shits, and we don't let them hang with kids who are.
As long as they let us know where they are and check-in on occasion, our kids got "go-out-and-play privileges" that extended beyond the street we live on when they were about ten. By then they knew the safety rules and, more importantly, knew that if they misbehave it would get quickly back to us.
On Halloween night they don't stomp across lawns, kick over pumpkins or take entire bowls of unattended candy, and they know to be polite and say thank you.
That said, we trick-or-treat as a family event because we enjoy spending the time together. If the kids wanted to go without adults I would want at least one 13-14 year-old in the group because they are usually out after dark.