Create a Safe Space for Rally to Play

Hi! Meet Rally. Rally is 6 years old with level 3 Autism. We need to install a fence in our yard for Rally to have a safe space to play outside. Part of Rally's problems is elopement, which means he will take off running without concern for safety. Once he takes off running, he does not stop until he is caught, which can take a little bit because he is very fast. Everyone who has ever had to one-on-one him can verify this child has a need for speed in those little feet! When he is on a mission, he goes for it. So please help me give this guy a safe spot at home to play.