Traffic control, including what vehicles can use which roads is a solved problem. There are standard road signs that tell human drivers the rules of the road. Car companies have spent a fortune in developing computer vision algorithms to read signs meant for humans.
As semi and fully autonomous vehicles become more prevalent, traffic control signage should adapt. The addition of QR codes to existing signs, or additional signs, that specify rules of the road seems to be an obvious (to me anyway) progression. The codes can provide traffic control information, including no autonomous vehicles operation this road, this road between (time) and (time) etc.
But what about people defacing the codes to give improper directions? Well, what about people who deface current signs that people read? Removing traffic control signs, altering the speed limit, is already a thing, and there are legal consequences for doing so.
Technology has progressed, signage just needs to catch up.