Earlier quoted context omitted.
Well, if truck driving were automated, they certainly wouldn't lower then. Personally, I imagine a lot of companies will use that extra money to buy out, take over, or otherwise eliminate their competition. I doubt the consumer will win.
If transport companies don't lower prices, won't new companies enter the market and undercut the incumbents?
And so long as the cost to get into the industry is high (the up-front cost of a driver is effectively 0, whereas AI will be non-0), and the incumbents have the ability to drop their prices lower than any new startup (thanks to the efficiencies of scale), serious new competition will be rare.
Even considering all that, the cost for shipping something is remarkably low to begin with. $400 for an 40' shipping container worth of goods over 300 miles? Drop the driver from the equation entirely, and that cost would only go down by about $100. As a point of reference, a 40' shipping container full of bananas is worth in excess of $58,000 (1000 boxes per container, 100 bananas per box, $0.58 per banana).