It's the loading docks, the fueling stations, the truck scales and all the rest of the infrastructure that supports trucking.
All of those are going to need to have "automated truck" support as well, not to mention, when an 18 wheeler blows out a tire, you need some skills to bring the truck to a successful stop, but even more skills and equipment to effect the repair.
Mining operations are easier because they work on their own property and aren't required to mix with other passenger vehicles.
I know you said "eventually," but I suspect that it's going to take at least 50 years before we're anywhere even close.