I let my 5 year old do this. Our neighbors have a few kids. We are not close with the parents but we have had a few conversations. I sit out front and read my Kindle while she is playing. Sometimes she is out of eyesight because big cars block the way. Yesterday I went in the house for something but when I came out she went in the road to play football with a new kid who just arrived. She took one look at me and ran back to the side. Then she got time-out later. I'm going to give her another chance. But just wondering if people are more lenient or more supervision in this situation.