There’s this story where a truck owner had a tyre changed, only for his driver to subsequently refuse to drive the truck because the changed tyre was dangerous.
What would a “driverless” truck do in this case?
If you think about it, you come at the core of the meaning of “driver” and “driverless”. The driver is not just someone who monitors the road ahead and decides when to press the brakes. The driver is the person responsible for the vehicle while it is on road. While there have been trains with no on-board personnel for some time, they aren’t driverless; there’s a human somewhere who controls them remotely, and has cameras and other equipment to monitor them.
That’s why the word “driverless” is misleading. Unless we can achieve level-5 autonomous driving—which we can’t with current and foreseeable technology—trucks might only reach the stage of being unmanned, not driverless.