Buggy advice for 2yr escape artist

Does anyone have any advice on buggies my little boy is 2 he has been diagnosed with autism has very high sensory needs and is a runner See no evil, he still fits in a standard size buggy fine but we are yet to find anything that keeps him in we have a out about nipper which he has a extra strap attached but still manages to climb out, we had a little pop up buggy but he would tip the whole thing over leaning out forward im getting abit desperate at I need to get my older child to school any ideas tips or buggy suggestions very much appreciated x