The Europeans have tested automated trucks as a "train", with one driven by a human in front and the others following along. A test was done with this "train" crossing Europe, and it worked. The story I saw seemed to show the trucks essentially tailgating each other; there really wasn't enough space between them for other vehicles to safely merge/weave, though an aggressive driver in a small car could probably accomplish it, so essentially it was a single truck several hundred feet long for traffic purposes. With all of the angst in the past about convoys of doubles and triples clogging the right lane, think about that happening with HAL at the wheel of most of them (probably more reliable, as noted) and the "convoy" being arbitrarily long.

The spacing thing probably needs to be worked on for this to be socially acceptable, but that's a technical detail. Once HAL figures out how to follow the leader, adjusting spacing to allow safe weaving by other drivers can be done. So now we have, what, one driver for a dozen or more trucks? Sounds like a rubber-tired freight train...