I’m not in the hijacking business, but I would think a truck on a lonely stretch of road is a better candidate for theft if there is no driver. No witness, and the crime is a much lower priority for cops if there is no dead or injured driver. Have you invested in the robot technology by chance? I’m not against it, but I can see that there will be lots of problems, some of which have not been foreseen.
There would be no cops at all if the rig is human-driven. It is possible to stop the vehicle without alerting the driver - and then it's too late. For example, park two of your cars so that they look like crashed one into another (and block the road.) The trucker will stop and exit the cab to see what's up. If he doesn't, an accomplice with a handgun may jump onto the tractor and point a gun at him. No dialing 911 in this situation. But a robot would send the signal to the HQ, gun or no gun.
Have you invested in the robot technology by chance?'
I have exactly zero investments into stock market. I am not a gambler. I have some bonds, though. I am not working on robots myself, but I work with similar equipment and have a rough idea what robot builders are up to. Sure there are problems... but what would you say in the year 1880 if someone tells you that soon people will be riding in horseless carriages, ten times as fast as a horse can run, and hundred times as far? A journey of a thousand miles begins with a single step.