I think the challenge of remotely controlling a truck is not the technology. There are lots of videos on youtube of guys who convert cars to remote controls in their garage. Mythbusters did it regularly for some of the car-related myths. (I do not mean to belittle the work of Starsky Robotics, just noting that they're "formally" doing stuff that people have already been doing for a while now).

The challenge is; who changes a flat tire? who inspects the vehicle after it's been parked? who hooks up all the break lines to the trailer? who gasses it up? who will check that the idiots on the dock loaded it correctly? who will smell the burning brakes on a steep incline? how will stranded trucks be rescued? The driver is kind of like a guardian of the freight, always looking out for the delivery's best interest, no matter the issue.

It's waaayy more of a business process and parternship problem than a technology one. You're going to have to negotiate contracts with tow truck companies and service stations across the continent. You're going to have to figure out some way to cross borders without a truck driver. You're going to have to hire all sorts of operations staff to manage the trucks. I'm actually much more curious about this aspect of the problem than the technology problem. I am tempted to think it takes more people to manage remote trucks than just having a driver.