We'll have arrived at the automated transit network when they stop putting up road signs. The cars know where they are, and how to get there. Signs are for fallible ignorant humans.
not if they're in a tunnel or a highrise canyon, or there is weather-related interference, or the maps have not been updated to reflect reality, or there is a detour for construction, etc.
Maybe in a 100% automated system we would replace the icons with QR codes or something but physical markers will likely be here to stay.