No, the license would only cover you from an extra ticket. I'm not overloaded, so how would that matter in case of an accident? It would just be an extra ticket. You'd face the same charges (if at fault) no matter what license you have. Now if I had 20K lbs behind me and got into an accident, I would be in some serious sh*t if at fault in case of an accident. As far as liability, I am under the GVW for my truck's intended towing capacity.