(a) This subchapter does not authorize the operation on the national system of interstate and defense highways in this state of a vehicle of a size or weight greater than authorized in 23 U.S.C. Section 127, as amended.
(b) If the United States government authorizes the operation on the national system of interstate and defense highways of vehicles of a size or weight greater than those authorized on January 1, 1983, the new limit automatically takes effect on the national system of interstate and defense highways in this state.