>>105985063
This. You could just slow down in front of those, have a couple people hop out and stand in its way while you unload it at your leisure. At least with a human driver involved the stakes are raised for potential privateers (violence, kidnapping and murder are very serious crimes compared to theft) and the vehicle/driver safety being tied together gives the cargo another layer of protection (a human driver can decide to just run someone over or smash into another vehicle to escape danger).