HOV and Express lanes make this easy. They have well established markings, limited access, and traffic goes in one direction. So industry and regulators would work together to solve standardization of markings for travel and entry and exiting.
Then you take it to the rest of the interstate system and then to limited access highways. Eventually you get down to the neighborhoods and city driving.
I see real promise in Tesla's beta system which has a few thousand drivers. What it tracks is far more advanced than what my current software does in my 3. They finally went to a persistent model and far better labeling. Now where my car shows cones around a parked vehicle they show the vehicle as well. They show all parked and stationary objects. Something the current software does not always do if at all.
Just within the US the lane markings, signage, and even signaling, is not consistent from state to state. Worse the rules for what is an acceptable lane is not consistent either. So the first step there is to standardize it all across the nation.