My kids are 7, 9, and 11. My 11 year old has been going across the street since he was about 8. He and the neighbor's son are best friends so I used to watch him run across the street.
Now as long as I know were they are they are allowed to play outside without me. Usually the 2 older ones do, but I have not really let me youngest go very far yet. She plays outside as long as her brothers are with her or if she has a friend. She also usually stays in the back unless there is a big group playing together.
Last summer we let the older 2, as long as they were together or with friends, ride their bikes around the block.
I think as long as they are together and you trust them and have taught them well then you have your answer.
at 9:01 AM on Jan. 1, 2009