There are a number of issues with this. The biggest one is that there is already a solution to the long distance safe movement of goods with minimal human involvement.
It is called a t-r-a-i-n.
Trucking companies already use long distance trains as alternatives to long distance truckers. It is far cheaper and less technologically risky to simply increase the amount of long distance freight that moves via railroad.
With driverless trucks, :
* each truck needs complex (expensive) electronics that need to be kept repaired and up to date
* regulatory hurdles
* liability issues
What happens when a computer has a memory corruption issue and shuts down halfway across Nevada?
For driverless trucks to be a real thing, the very real competition from the railroad industry needs to be addressed.
Based on past history, the railroad industry is going to be reminding all the regulators of how dangerous trucking (and now unmanned trucks) can be --- and how safe and proven the railroad alternative is.