mine run around but everybody's situation is different.
i have two that fly but have never run away. one has flown to the other side of a fence once and then come right back and the other has done it twice. the second they see you with food they're back of their own accord. i think they sort of establish their natural boundaries. for instance, mine have one area of the yard where they never go even though they could. so i imagine there is not enough cover there and they are afraid of predators or maybe hey there are no good bugs over there. i don't know.
i am not a chicken cuddler but they still know this is their home. even if one did get out, chances are it would come home at night. the habit behind the saying,,,,,,,his chickens came home to roost.