(A)(1) The gross weight of a vehicle or combination of vehicles, operated or moved upon any section of highway, including the interstate highway system, except where the formula in item (4) allows for a higher weight, shall not exceed:

(The following weight limits do not include applicable tolerances)

(a)Single-unit vehicle with two axles35,000 lbs. (b)Single-unit vehicle with three axles46,000 lbs. (c)Single-unit vehicle with four axles63,500 lbs.

except, on the interstate, vehicles must meet axle spacing requirements and corresponding maximum overall gross weights, not to exceed 63,500 lbs., in accordance with the table in item (4).

(d)Single-unit vehicle with five or more axles65,000 lbs.

except, on the interstate, vehicles must meet axle spacing requirements and corresponding maximum overall gross weights, not to exceed 65,000 lbs., in accordance with the table in item (4).

(e)Combination of vehicles with three axle50,000 lbs. (f)Combination of vehicles with four axles65,000 lbs. (g)Combination of vehicles with five or more axles73,280 lbs.

The gross weight imposed upon any highway or section of highway other than the interstate by two or more consecutive axles in tandem articulated from a common attachment to the vehicle and spaced not less than forty inches nor more than ninety-six inches apart shall not exceed thirty-six thousand pounds, and no one axle of any such group of two or more consecutive axles shall exceed the load permitted for a single axle. The load imposed on the highway by two consecutive axles, individually attached to the vehicle and spaced not less than forty inches nor more than ninety-six inches apart, shall not exceed thirty-six thousand pounds and no one axle of any such group of two consecutive axles shall exceed the load permitted for a single axle.

The ten percent enforcement tolerance specified in § 56-5-4160 applies to the vehicle weight limits specified in item (1), and subsections (B) and (C). However, the gross weight on a single axle operated on the interstate may not exceed 20,000 pounds, including all enforcement tolerances; the gross weight on a tandem axle operated on the interstate may not exceed 35,200 pounds, including all enforcement tolerances; the overall gross weight for vehicles operated on the interstate may not exceed 75,185 pounds, including all enforcement tolerances except as provided in item (4).

(2) Enforcement tolerance is fifteen percent for a vehicle or trailer transporting unprocessed forest products only on noninterstate routes.

(3) Enforcement tolerance is fifteen percent for a vehicle or trailer transporting sod only on noninterstate routes.

(4) Vehicles with an overall maximum gross weight in excess of 75,185 pounds may operate upon any section of highway in the Interstate System up to an overall maximum of 80,000 pounds in accordance with the following:

The weight imposed upon the highway by any group of two or more consecutive axles may not, unless specially permitted by the Department of Public Safety, exceed an overall gross weight produced by the application of the following formula:

W = 500 (LN/N-1 + 12N + 36)

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

As an exception, two consecutive sets of tandem axles may carry a gross load of 68,000 pounds if the overall distance between the first and last axles of the consecutive sets of tandem axles is 36 feet or more. The formula is expressed by the following table:

Distance in feetMaximum load in pounds carriedbetween theon any group of 2extremes of anyof 2 or more consecutive axlesgroup of 2 or more consecutive axles 2 axles3 axles4 axles5 axles6 axles7 axles435,200 535,200 635,200 735,200 8 and less35,20035,200 more than 838,00042,000 939,00042,500 1040,00043,500 11 44,000 12 45,00050,000 13 45,50050,500 14 46,50051,500 15 47,50052,000 16 48,00052,50058,000 17 48,50053,50058,500 18 49,50054,00059,000 19 50,50054,50060,000 20 51,00055,50060,50066,000 21 51,50056,00061,00066,500 22 52,50056,50061,50067,000 23 53,00057,50062,50068,000 24 54,00058,00063,00068,50074,00025 54,50058,50063,50069,00074,50026 55,50059,50064,00069,50075,00027 56,00060,00065,00070,00075,50028 57,00060,50065,50071,00076,50029 57,50061,50066,00071,50077,00030 58,50062,00066,50072,00077,50031 59,00062,50067,50072,50078,00032 60,00063,50068,00073,00078,50033 64,00068,50074,00079,00034 64,50069,00074,50080,00035 65,50070,00075,000 36 68,00070,50075,500 37 68,00071,00076,000 38 68,00071,50077,000 39 68,00072,50077,500 40 68,50073,00078,000 41 69,50073,50078,500 42 70,00074,00079,000 43 70,50075,00080,000 44 71,50075,500 45 72,00076,000 46 72,50076,500 47 73,50077,500 48 74,00078,000 49 74,50078,500 50 75,50079,000 51 76,00080,000 52 76,500 53 77,500 54 78,000 55 78,500 56 79,500 57 80,000

(B) On the interstate and noninterstate highways of this State, any over-the-road bus as defined in Title 49 of the United States Code, motorhome, or any vehicle which is regularly and exclusively used as an intrastate public agency transit passenger bus as defined in Title 49 of the United States Code, is excluded from the axle spacing requirements in subsection (A). However, these vehicles are limited to a maximum single axle weight limit of twenty-four thousand pounds, including all enforcement tolerances.

(C) Except on the interstate highway system:

(1) Dump trucks, dump trailers, trucks carrying agricultural products, concrete mixing trucks, fuel oil trucks, line trucks, and trucks designated and constructed for special type work or use are not required to conform to the axle spacing requirements of this section. However, the vehicle is limited to a weight of twenty thousand pounds for each axle plus scale tolerances and the maximum gross weight of these vehicles may not exceed the maximum weight allowed by subsection (A)(1) for the appropriate number of axles, plus allowable scale tolerances.

(2) Concrete mixing trucks which operate within a fifteen-mile radius of their home base are not required to conform to the requirements of this section. However, these vehicles are limited to a maximum load of the rated capacity of the concrete mixer, the true gross load not to exceed sixty-six thousand pounds. All of these vehicles shall have at least three axles each with brake-equipped wheels.

(3) Well-drilling, boring rigs, and tender trucks are not required to conform to the axle spacing requirements of this section. However, the vehicle is limited to seventy thousand pounds gross vehicle weight and twenty-five thousand pounds for each axle plus scale tolerances.