Thirty days and turn em' loose comes to mind. I recall a couple of instances while living in eastern PA. All of these bridges were well marked. The 8 ton limit between Riverton, PA and Belvidere, NJ replete with officer on duty. The "free bridge" between Phillipsburg, NJ and Easton, PA, again with weight signs and "officer on duty". I think there was at least one over the bridge in Reiglesville. I can also recall at least one einstein taking out a covered bridge in the eastern PA area.
Perhaps reading ability should be a CDL requirement? Then there are the fines which run into several thousands of dollars just for crossing. Destroying the bridge? O'man!