Dr. Thompson really helps clarify why children with an ASD may respond to their environment in a less than socially acceptable manner. He also addresses what to do when this happens - including when out in public.
Regarding this topic, I also added a template of public awareness cards (or Public Awareness "Needed" Cards for young children and for teenagers). These cards can be handed out when you don't feel like giving an explanation. :) I placed them under "resources", but I'll add them here also.
Hope you are having a great day!