I think for long-haul trucking it’s certainly pretty hard to stay fully tuned while driving for such long times. And for truck companies, they can save tons of money on labor when they don’t have to pay the driver for the hours on the road and just for the manual disconnect/connect docking. Maybe they can make it fully automated, but why haven’t any trucks done that already? It’s an easier problem to solve than self-driving.
* by convoy, I mean that one truck up front was driven by a human and then a few were automated to draft from directly behind to just follow the truck in front of them.
EDIT: Here's a source for the 90s, where this paper had a few authors from Volvo.
from: http://orfe.princeton.edu/~alaink/SmartDrivingCars/ITFVHA15/...
>Additionally, different applications of automated driving for trucks have been demonstrated across the globe since the 1990’s. The focus has been on proof of concept for truck platooning due to the foreseen fuel economy and traffic flow benefits.