In a "futuristic" society (think Ghost in the Shell or Human Revolution), where you have AI driving vehicles that carry goods in a reliable way, is there any reason to have a human traveling with the cargo? Is there any reason to have a cabin for that matter?
The "hauler" unit is capable of sending a distress signal if anything goes wrong along the road, which in this case means something out of the control of the AI happened.
The AI is connected to a Network, but is perfectly capable of finishing the travel in case of a disconnection. Technicians can remotely control the unit at any time. They use airless tires so no punctures.The vehicle is electric, and no recharge is required for the distances they are meant to travel.The cargo container can only be opened at the intended destination, until then is practically sealed.
The setting for this is that I need cargo disappearing from containers in a mysterious way, no witnesses, so I need the human out of the formula, but I want to have a good reason for it to not be there. This type of transport is commonplace and cheap as can be. This is just for city to city transport, local delivery trucks would still require people. Note that this is for regular stuff, it is to be understood valuable cargo would still go escorted.