What's more likely is the computer will load the container using automated forklifts (already in use in many Amazon warehouses). Then, the robo-truck will dray it to a suitable transload and a computerized crane will drop it on a ship or a train. Then the train or boat (by then single-operator (train) or minimal crew (boat) essentially supervising an automated operation similar to BART) will move the box to another transload near its destination where a robo-truck will take over again.

You & George are right that it will be difficult for robo-trucks to handle unpredictable weather conditions; a driver will be needed at those times, using the robo-features for cruise control once things are settled. Wonder where we'll find them?

This is capitalism at its finest - substituting capital (robots) for labor. Considering how often humans are needed to manage automated BART trains (at every station, usually), I'm not counting on it working all that well in a pure configuration. It is duly noted, however, that Vancouver BC has run its "Skytrain" system from the beginning with no human train operators, so in principle it's possible.