I work as a physical therapist in a school district. Preschool is only at certain campuses within the district so he needs to go to the school they can provide the best services for him. The bus he will ride will have an aide to help them get on and off the bus. They will NOT let him off without you being right there to pick him up and they will not release him to anyone but one of his parents unless you make other arrangements before hand. You will not be allowed to ride the bus. He will be on the bus with only other preschoolers his age (3-5). I would let him ride the bus. If he is really small or has low tone, they provide car seats for the children. He will be supervised the entire time.