Little 7 year old girl was killed in quad bike accident day after christmas a couple of years ago. about a half a year later her father was arrested for manslaughter.
He was in his car on dark county road, escoting his 2 kids on their quad bikes back to their home, when an oncoming car, passed him and some how struck the quad bike his daughter was following on. Whether she wandered over to the other side of road, or because county lanes are so narrow and she didn't pull over for on coming car, is not known.
Maybe I am over cautious, but if I ever let my kids on one of those things, which I wouldn't, it would only be in a field, after they had all the safety lessons and with correct protective gear.