Ever hear of PTC? Positive train control. I install those systems on 3 to 4 locomotives a week. It’s a system designed to stop a train if the crew fails to follow a tightly controlled schedule. The train is controlled by a back office hundreds to thousands of miles away from the train.
The technology at this point is as reliable as the weather.
Automated freight trains will be viable just as soon as remote control tractor trailors, ships, and passenger vehicles are mandated.