Volvo Trucks is doing a lot of work on that. There are various "tricks" like going along a fixed route, or several automatic trucks following a leader truck with a driver.
Arguably so, but freight trains (outside of large countries like the US) have taken a total battering from the truck market.
In the UK for example it's just not worth putting stuff from port -> train -> truck -> store. Much easier to do port -> truck.
Combine that with the EU's very strict laws on driving time and this is a giant market.
When people complain about how insanely sci-fi it feels. I often get the DLR (docklands light railway) in London. It's totally automated - you can sit in the drivers seat if you want. I have no idea how crazy people would of thought of this idea in the 1960s.
PS: I am a huge fan of getting rid of trucks on the road, but in the UK it doesn't make any sense.
The UK is pretty compact. If you have a distribution center in the middle of it, then just about everywhere you could possible want to get stuff to is less than a 6-7 hours drive away.
All of the above, really. It's a crowded country which strenuously objects to building across the countryside, so re-expanding the rail network is hard and the existing network is fairly full of passengers. The key ports don't necessarily have good rail links. Generally once containers are landed they're taken to a distribution center in the Midlands, taken out of the container and re-packed onto pallet trucks to individual stores.
And able to go to places (within a few meters, or less) where there are no rails, variable size (when was the last time you had a train deliver a single refrigerator), and flexible to change where to drive and where to without the decade or so it takes to get a new railway and stations planned, approved, build and operationalized.
