(a) As used in this Code section, the term:

(1) "Federal bridge formula" means:

LN W = 500 --- + 12 N + 36 N-1

Where W = the overall gross weight on any group of two or more consecutive axles to the nearest 500 pounds, L = the distance in feet between the extreme of any group of two or more consecutive axles, and N = the number of axles in the group under consideration.

(2) "Lift axle" means any axle on any vehicle manufactured after July 1, 1978, which axle may be raised or lowered with respect to the horizontal plane of the vehicle.

(3) "National highway" means any highway which constitutes a part of The Dwight D. Eisenhower System of Interstate and Defense Highways as used in Section 127 of Title 23 of the United States Code.

(4) "Single axle" means all the wheels whose centers may be included between two parallel transverse vertical planes 40 inches apart.

(5) "State bridge formula" means:

LN W = 500 --- + 12 N + 36 N-1

Where W = the maximum allowable gross weight of the vehicle or combination of vehicles to the nearest 500 pounds, L = the distance in feet between the first and last axles of the vehicle or combination of vehicles, and N = the number of axles on the vehicle or combination of vehicles.

(6) "Tandem axle" means, until April 1, 1988, two or more consecutive axles, excluding the steering axle, which extend across the full width of the vehicle and whose centers may be included between parallel vertical planes spaced more than 40 inches apart but not more than 96 inches apart.

(7) "Tandem axle" means, after April 1, 1988, two or more consecutive axles, excluding the steering axle, which extend across the full width of the vehicle and whose centers may be included between parallel vertical planes spaced more than 40 inches apart but not more than 216 inches apart.

(b) Except when authorized by a permit issued pursuant to Code Section 32-6-28 and except as otherwise provided in this Code section:

(1) No vehicle equipped with high pressure pneumatic, solid rubber, or cushion tires and operated upon any public road of this state shall carry a load on any wheel which exceeds 8,000 pounds by more than 13 percent or a load on any single axle which exceeds 16,000 pounds by more than 13 percent; and

(2) No vehicle equipped with low pressure pneumatic tires and operated upon any public road of this state shall carry a load on any wheel which exceeds 9,000 pounds by more than 13 percent or a load on any single axle which exceeds 18,000 pounds by more than 13 percent.

(c)(1)(A) On all highways within this state which are not national highways, the maximum total gross weight authorized for any vehicle and load shall not exceed 80,000 pounds; the maximum load authorized on any single axle shall be as provided in subsection (b) of this Code section; the maximum load on any tandem axle shall be 40,680 pounds; and subject to subparagraph (B) and subparagraph (C) of this paragraph, the maximum total gross weight authorized for any vehicle and load shall be the maximum load authorized on any single axle multiplied by the number of axles with which the vehicle is equipped.

(B) For vehicles and loads with an actual total gross weight between 73,280 pounds and 80,000 pounds, the maximum total gross weight authorized for the vehicle and load shall be determined by applying the state bridge formula.

(C) For any vehicle equipped with four axles, the maximum total gross weight authorized for the vehicle and load shall be 70,000 pounds.

(2) Reserved.

(3) After April 1, 1988, no lift axle may be used in computing the maximum total gross weight authorized for any vehicle or load.

(d)(1)(A) On all highways within this state which are national highways, except as provided in paragraph (2) of this subsection, the maximum total gross weight authorized for any vehicle and load shall not exceed 80,000 pounds; the maximum load authorized on any single axle shall be as provided in subsection (b) of this Code section; and, except as provided in subparagraph (B) of this paragraph, the maximum overall gross weight in pounds on a group of two or more consecutive axles shall be determined by applying the federal bridge formula. In applying the formula, no lift axle shall be counted as an individual or additional axle when determining the maximum overall gross weight.

(B) Notwithstanding the provisions of subparagraph (A) of this paragraph, the maximum load authorized on any tandem axle shall be 34,000 pounds, and any two consecutive sets of tandem axles may carry a gross load of 34,000 pounds each if the overall distance between the first and last axles of such consecutive sets of tandem axles is 36 feet or more; however, except for vehicles and combinations of vehicles exceeding 55 feet in length, the maximum gross weight authorized on a tandem axle for a vehicle or combination of vehicles carrying a gross weight of less than 73,280 pounds shall be 40,680 pounds. (2)(A) Any vehicle registered with the Department of Revenue prior to April 1, 1983, shall be exempt from the provisions of paragraph (1) of this subsection until April 1, 1988, upon obtaining a special permit from the department or upon being otherwise exempt under an agreement entered into pursuant to the provisions of subsection (e) of this Code section. This permit shall be issued for identification purposes, shall be nontransferable, and shall be terminated on April 1, 1988. For vehicles operating on highways within this state which are national highways under a permit issued under this paragraph, the maximum total gross weight authorized for any vehicle and load shall not exceed 80,000 pounds; the maximum load authorized on any single axle shall be as provided in subsection (b) of this Code section; except as provided in subparagraph (B) of this paragraph, the maximum load on any tandem axle shall be 40,680 pounds; and, except as provided in subparagraph (C) of this paragraph, the maximum total gross weight authorized for any vehicle and load shall be the maximum load authorized on any single axle multiplied by the number of axles with which the vehicle is equipped.

(B) For vehicles or combinations of vehicles carrying a gross weight of more than 73,280 pounds or for vehicles or combinations of vehicles exceeding 55 feet in length, the maximum gross weight authorized on a tandem axle shall be 34,000 pounds.

(C) For vehicles or combinations of vehicles carrying a gross weight of more than 73,280 pounds, the maximum total gross weight authorized for any vehicle and load shall be determined by applying the federal bridge formula. In applying the formula, no lift axle shall be counted as an individual or additional axle.

(3) If at any time federal law authorizes any weight greater than that authorized by this subsection, such greater weight under federal law shall be authorized on the national highways within this state.

(e)(1) Subject to the provisions of this article, the department shall be authorized, on behalf of the state, to enter into agreements with the United States Secretary of Transportation as provided in Section 127 of Title 23 of the United States Code, relating to the control of vehicle weight and width limitations, which agreements shall exempt certain vehicles from the requirements of subsection (d) of this Code section. The department shall be authorized to take action in the name of the state to comply with the terms of any such agreement and to promulgate any rules and regulations necessary to ensure the department's compliance with federal laws and to provide for the issuance of the special permits required by this Code section.

(2) The department shall include in any agreement with the United States Secretary of Transportation a provision which ensures that any vehicle registered with the Department of Revenue prior to April 1, 1983, shall be exempt from the application of the federal bridge formula as required by subsection (d) of this Code section if the vehicle otherwise complies with the provisions of paragraph (2) of subsection (d) of this Code section and obtains a special permit from the department. The department shall also include in any agreement with the United States Secretary of Transportation a provision which ensures that any lift axle may be counted as an individual or additional axle when computing the maximum total gross weight authorized for a vehicle and load below 73,280 pounds as provided in subparagraph (d)(2)(A) of this Code section.

(3) Any agreement entered into pursuant to this subsection shall be terminated April 1, 1988.

(f) On any public road of a county road system, the maximum total gross weight of a vehicle and load shall not exceed 56,000 pounds unless the vehicle is making a pickup or delivery on such road; except that if a county road is constructed to the same standards as those highways of this state which are national highways and is authorized as a designated local truck route pursuant to official resolution of the county and approval of the commissioner, the maximum weight limits for such designated local truck route shall be the same as those for highways in this state which are not national highways as provided by paragraph (1) of subsection (c) of this Code section.

(g)(1) The weight limitations provided for in this Code section, except the limitation in subsections (f) and (h) of this Code section, may be exceeded on any public road within this state which is not a national highway, or when making a pickup or delivery on any public road of a county road system, without a permit when the load on any single axle does not exceed 23,000 pounds and the maximum total gross weight of the vehicle and load does not exceed 80,000 pounds when:

(A) Hauling forest products from the forest where cut to the owner's place of business, plant, plantation, or residence;

(B) Hauling live poultry or cotton from a farm to a processing plant;

(C) Hauling feed from a feed mill to a farm;

(D) Hauling granite, either block or sawed for further processing, from the quarry to a processing plant located in the same or an adjoining county; or

(E) Hauling solid waste or recovered materials from points of generation to a solid waste handling facility or other processing facility.

(2) Any vehicle carrying a load as authorized in this subsection at night shall be equipped with lights clearly visible for a distance of not less than 300 feet from the front and rear of the vehicle.

(h) Notwithstanding any provision of this Code section to the contrary, no vehicle or combination of vehicles shall be operated over any bridge with a posted limit which is less than the total gross weight of the vehicle and its load.

(i)(1) Any vehicle which can be made to comply with the requirements of this Code section by shifting the load and which is then loaded to comply with this Code section shall not be held to be in violation of this Code section. (2) On all highways within this state which are not national highways:

(A) Except as provided in subparagraph (B) of this paragraph, for all vehicles, fines for violations of the total gross weight limitations provided for in subsection (c) of this Code section shall be based on the amount by which the actual weight of the vehicle and load exceeds the allowable maximum weight determined under subsection (c) of this Code section.

(B) For vehicles equipped with four axles, fines for violations of the total gross weight limitations provided for in subsection (c) of this Code section shall be based on the amount by which the actual weight of the vehicle and load exceeds 70,000 pounds.

(j) Except as provided in subsections (f) and (h) of this Code section, weight limits and axle definitions for any bimodal semitrailer, semitrailers, and trailers operated on highways and public roads within this state shall be weight limits and axle definitions authorized by federal law governing national highways.