Airliners once flew with three people up front. Two flew the aircraft. The third, the flight engineer, watched the engines, the fuel and the systems, and kept an eye on the crew, so the pilots never had to wonder what the machine was doing.
Automation took over that seat in the 1980s. Trucks never had one.
So a truck still breaks down in the middle of a run with no one aboard who knows why. Its service runs on the average of all trucks, not on what this one needs. And its driver rides alone through the night.