18-wheel trucks require Commercial Driver's Licenses (CDLs) with stricter requirements, enforced regulation, and stricter safety oversight. Originally, so did package delivery vans and trucks in many states. It was deregulated by most states so that CDLs were no longer required for several classes of large trucks and vans, and it is those same deregulations that have allowed many "residential" vehicles to grow in size to fit those older categories that used to be classed solely for commercial vehicles (with stricter licensing standards and safety oversight).

The safety problem isn't and never has been commercial vehicles, it has been that America has let the definition of commercial vehicle erode to the point that many Americans believe that exorbitantly sized commercial vehicles make decent residential vehicles.