Occam's Razor here being to create some kind of automated firearm attached to the truck, the deadly superhuman speed and accuracy of which would act as a deterrent to freight thieves. This solution would have the extra benefit of adding some real suspense to the hijackings and robberies that do happen.

This is a serious comment and I can't think of any possible way in which this plan could backfire. There is nothing dystopian about automated trucks with AI-powered, high-precision guns filling America's highways 30 years in the future.