Section 621.206(a) does not apply to a vehicle to which this subchapter applies to the extent that section prescribes a limit on the extension of the load beyond the rear of the vehicle. Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995. Sec. 622.045. INTERSTATE AND DEFENSE HIGHWAYS. (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 those permitted under 23 U.S.C. Section 127, as amended.(b) If the United States authorizes the operation on the national system of interstate and defense highways of a vehicle of a size or weight greater than those permitted under 23 U.S.C. Section 127 on August 29, 1997, the new limit automatically takes effect on the national system of interstate and defense highways in this state. Added by Acts 2001, 77th Leg., ch. 941, Sec. 36, eff. Sept. 1, 2001.