The PACE of progress accelerates.
Every time I get into discussions of this sort I halve my estimate of how long it will take to get to any given milestone (Some sort of Moore's law ?)
I used to think 20 years in the future, then 10, 5, now 2 or 3 - but I have suspicions that a lot more is possible than is being released ...e.g. the big GM shutdowns could indicate retooling for (as Monty Python's show used to say) something completely different, Ford is supposedly getting out of gas driven cars, etc.
Sure, trucks will be first largely because of the economics - can drive tirelessly 24x7, might need a human assistant (who can be resting most of the time, but can't be drunk, could be on board but essentially on-call) once in a while.
GPS has had the country's roads all mapped out for a long time now and it isn't THAT MUCH data (by modern standards of large data).
The detail mapping is just more data - just data in more detail. That removes a lot of the need to "see" lane markings or take the correct lane when there are no markings, or snow covers everything.