61-10-107. Maximum gross weight -- when permit required. (1) An axle may not carry a load in excess of 20,000 pounds, and no two consecutive axles more than 40 inches or less than 96 inches apart may carry a load in excess of 34,000 pounds. An axle load is the total load transmitted to the road by all wheels whose centers are included between two parallel transverse vertical planes 40 inches apart, extending across the full width of the vehicle. For purposes of this section, axles 40 inches or less apart are considered to be a single axle. A vehicle or combination may not have more than nine axles. The maximum gross weight allowed on a vehicle, group of axles, or combination of vehicles must be determined by the formula:
          W = 500((LN/(N - 1)) + 12N + 36)

     in which W equals gross weight, L equals wheel base in feet, and N equals number of axles, except that 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 the consecutive sets of tandem axles is 36 feet or more.
     (2) (a) Notwithstanding a vehicle's conformance with the requirements of subsection (1), except for the steering axle, all axles weighing over 11,000 pounds must have at least four tires or have wide-base tires. The maximum load on an axle, other than a steering axle, equipped with wide-base tires is limited to 500 pounds per inch of tire width.
     (b) The provisions of subsection (2)(a) do not apply to passenger buses.
     (c) For the purposes of this section, wide-base tires are tires that are 14 or more inches in nominal width. The maximum tire weight limit is computed for wide-base tires based on the number of inches shown on the tire marking, or if the tire marking is shown by metric size, the tire weight limit is computed by conversion of the metric size.
     (3) If the gross weight of a vehicle or combination exceeds 80,000 pounds, the vehicle or combination must have a special permit. The permit may be issued in the discretion of the department of transportation based on evaluation of safety, highway capacity, and economics of highway maintenance and vehicle operation. The fee is $20 per trip permit or $100 per term permit. A term permit may not be issued for a period of time greater than the period for which the GVW license is valid. Owners of vehicles licensed in other jurisdictions may, at the discretion of the department, purchase permits to expire with their registration. Permits may specify and permits issued under 61-10-124(6) must specify highway routing.
     (4) A special permit issued under subsection (3) for the transportation of agricultural products by farm vehicles from a harvesting combine or other harvesting machinery to the point of first unloading is for the full term of the harvest season of the agricultural product transported.
     (5) This section does not apply to highways that are a part of the national system of interstate and defense highways (as referred to in 23 U.S.C. 127) when application of this section would prevent this state from receiving federal funds for highway purposes.

     History: En. 32-1123.7 by Sec. 18, Ch. 316, L. 1974; R.C.M. 1947, 32-1123.7; amd. Sec. 3, Ch. 40, L. 1981; amd. Sec. 2, Ch. 366, L. 1981; amd. Sec. 1, Ch. 392, L. 1981; amd. Sec. 2, Ch. 487, L. 1983; amd. Sec. 3, Ch. 474, L. 1987; amd. Sec. 1, Ch. 235, L. 1989; amd. Sec. 49, Ch. 16, L. 1991; amd. Sec. 3, Ch. 512, L. 1991; amd. Sec. 1, Ch. 399, L. 1993; amd. Sec. 2, Ch. 236, L. 1995.