Notwithstanding any contrary provisions of this chapter, a motor vehicle designed and used for the hauling of refuse shall not be subject to state axle weight restrictions when hauling refuse. Nothing in this provision shall waive or modify existing state gross weight restrictions for refuse vehicles or other size and weight restrictions. To the extent that application of this section to highways which are part of the national system of interstate and defense highways would cause this state to be deprived of any federal funds for highway purposes, this section shall not be applicable to highways which are part of the system. Nothing in this section shall permit these vehicles to travel over any structure, highway, or portion of highway that is weight restricted for the vehicle load.