DB wrote:
"It will probably end up like a train engineer. They don't much while at cruising speed but they have to be present."
You might be surprised at what an engineer has to do to -keep- a train "at cruising speed", be it a passenger or freight train.
It's not like a plane that can be switched to autopilot.
There's no equivalent on trains (at least, not yet).
The faster the train is moving, the -more- there is to keep an eye on.
There are relatively few areas anywhere in the country where a railroad is built on flat, straight track. Terrain changes, upgrades, downgrades, slowdowns, curves -- all require some degree of action on the part of the engineer, even just adjusting throttle, using brakes, etc.
Addendum:
Tell me what this sentence means:
"Kid, ya gotta run the train. You can't let the train run you!"
Sounds like a play on words, right?
Took me YEARS to fully get a grip on that… ;)