Long-haul is more than just driving. Will smart trucks be able to put chains on and pull them off when necessary? Handle unloading of items of weighing process proves problematic? Call for pick up of items removed during weighing? Handle snow? Handle loss of sensors? Handle run away down hill on a steep incline. None of these are insurmountable, but all are well out of the current horizon. Heck, just refueling is hard.
Most of those can be solved by changes to the truck or delivering spot local drivers. For weighing the trucks could run different trailers with load cells to weigh itself to ensure they're under the weight limit for their route. For snow there are automatic chain systems used on buses today those might be adaptable. Run away ramps are usually marked so a combination of good mapping data for route planning and finding run offs and vision/driving they'll have anyways.
