Commercial motor vehicles play an important part in speed control. With the advent of slower vehicles, your reckless speed demons will stomp the gas even more. Right now law enforcement and big rig trucks are the only thing keeping you safe on the highways. Removing big rig trucks is a recipe for disaster and violence.
You know those trucks? They're dirty, smelly, big and get in the way of you just trying to go to work or school or whatever, right? Well, without those trucks, you wouldn't have the supplies you need at work or school. You wouldn't be able to get food at the store. Or cheap goods at WalMart. Restricting them to just some roads because you don't like them is impractical and will just end up costing you more in the long run. Not to mention that corporations pay taxes, too, and have a right to use the roads just like we do.