Generally the movement of cargo at high speeds is one of those things
that I believe will have a human operator as a safety feature, simply
because humans get nervous when thinking of unsupervised blocks of
mass moving at high speed. The "gravitruck" is a ubiquitous vehicle in
my games, essentially being a manned grav vehicle with capacities in
the tens to hundreds of tons. For really big-ass mass movement without
mucking up the environment, maglev or grav-float "trains" on fixed lines
would do the job nicely and could conceivably automatically, but humans
might be handy there too.
I conceive of a situation where a trucker drives out of East Phart with
his grav-hauler groaning under a tandem cargo pallet weighing 100 tons
or more, drives it down local roads carefully, gets to larger highways w
where he can drive with impunity, and after no more than 100 Kilometres
reaches the "Mainline", where he locks into a traffic control program,
kicks up his feet, and sleeps while robots convey him across the continent
at high speed. Then, at the other end, he wakes up, gets off the Mainline,
and wends his way down smaller and smaller roads until he makes his delivery
at Pymple's Corners.....
metlay