Weight limitations on class “A” highways
Wis. Stat. § 348.15
in effect(1) In this section “class ‘A’ highway” includes all state trunk highways and connecting highways and those county trunk highways, town highways and city and village streets, or portions thereof, that have not been designated as class “B” highways pursuant to s. 349.15.
(3) Subject to any modifications made by a 1st class city under s. 349.15 (3) and except as provided in s. 348.17 (5) or (6), no person, without a permit, may operate on a class “A” highway any vehicle or combination of vehicles unless the vehicle or combination of vehicles complies with the following weight limitations:
(a) The gross weight imposed on the highway by any one wheel or multiple wheels supporting one end of an axle may not exceed 11,000 pounds.
(b) The gross weight imposed on the highway by the wheels of any one axle may not exceed 20,000 pounds or, if the vehicle or combination of vehicles is an implement of husbandry or agricultural commercial motor vehicle, or is a 2-vehicle combination transporting by trailer or semitrailer an implement of husbandry or agricultural commercial motor vehicle to or from a farm-related destination, 23,000 pounds. In addition, the gross weight imposed on the highway by the wheels of the steering axle of a truck tractor may not exceed 13,000 pounds unless the manufacturer’s rated capacity of the axle and the tires is sufficient to carry the weight, but not to exceed 20,000 pounds.
(bg) In the case of a vehicle or combination of vehicles transporting exclusively milk from the point of production to the primary market and the return of dairy supplies and dairy products from such primary market to the farm, the gross weight imposed on the highway by the wheels of any one axle may not exceed 21,000 pounds or, for 2 axles 8 or less feet apart, 37,000 pounds or, for groups of 3 or more consecutive axles more than 9 feet apart, a weight of 2,000 pounds more than is shown in par. (c), but not to exceed 80,000 pounds. This paragraph does not apply to the national system of interstate and defense highways, except for the I 39 corridor and the I 41 corridor.
(br) In the case of a vehicle or combination of vehicles transporting exclusively peeled or unpeeled forest products cut crosswise or in the case of a vehicle or combination of vehicles transporting exclusively scrap metal, the gross weight imposed on the highway by the wheels of any one axle may not exceed 21,500 pounds or, for 2 axles 8 or less feet apart, 37,000 pounds or, for groups of 3 or more consecutive axles more than 9 feet apart, a weight of 4,000 pounds more than is shown in par. (c), but not to exceed 80,000 pounds. This paragraph does not apply to the national system of interstate and defense highways, except for the I 39 corridor and the I 41 corridor.
(bv) In the case of a vehicle or combination of vehicles used primarily for the transportation of septage, as defined in s. 281.49 (1) (m), the gross weight imposed on the highway by the wheels of any one axle may not exceed 21,500 pounds or, for 2 axles 8 or less feet apart, 37,000 pounds or, for groups of 3 or more consecutive axles more than 9 feet apart, a weight of 4,000 pounds more than is shown in par. (c) or, for groups of 4 or more consecutive axles more than 10 feet apart, a weight of 6,000 pounds more than is shown in par. (c) or, for groups of 5 or more consecutive axles more than 14 feet apart, a weight of 7,000 pounds more than is shown in par. (c), but not to exceed 80,000 pounds. This paragraph does not apply to the national system of interstate and defense highways, except for the I 39 corridor and the I 41 corridor.
(c) The gross weight imposed on the highway by any group of 2 or more consecutive axles of a vehicle or combination of vehicles may not exceed the maximum gross weights in the following table for each of the respective distances between axles and the respective numbers of axles of a group: [See Figure 348.15 (3) (c) following]
(d) Notwithstanding pars. (c) and (g), 2 consecutive sets of tandem axles may impose on the highway 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.
(e) Notwithstanding pars. (a), (b) and (c), in the case of a vehicle or combination of vehicles transporting exclusively livestock, the gross weight imposed on the highway by the wheels of any one axle or axle group may exceed the applicable weight limitation specified in pars. (a), (b) and (c) by 15 percent if the gross weight of the vehicle or combination of vehicles does not exceed the maximum gross weight specified for that vehicle or combination of vehicles under par. (c). This paragraph does not apply to the national system of interstate and defense highways, except for the I 39 corridor and the I 41 corridor.
(f)
1. In this paragraph:
a. “Heavy-duty vehicle” has the meaning given in 42 USC 16104 (a) (4).
b. “Idle reduction technology” has the meaning given in 42 USC 16104 (a) (5).
2. Notwithstanding pars. (a) to (c) and (g), sub. (4), and ss. 348.17 and 349.16, and subject to subd. 3., in the case of a heavy-duty vehicle equipped with idle reduction technology, the gross weight of the vehicle, and the gross weight imposed on the highway by the wheels of any one axle or axle group of the vehicle, may exceed the applicable weight limitation specified in pars. (a) to (c) or (g) or posted as provided in s. 348.17 (1) by not more than 550 pounds or the weight of the idle reduction technology, whichever is less.
3. This paragraph applies only if the heavy-duty vehicle operator, upon request, proves, by written certification, the weight of the idle reduction technology and, by demonstration or certification, that the idle reduction technology is fully functional at all times.
(g) Notwithstanding par. (c), if the vehicle or combination of vehicles is an implement of husbandry or agricultural commercial motor vehicle, or is a 2-vehicle combination transporting by trailer or semitrailer an implement of husbandry or agricultural commercial motor vehicle to or from a farm-related destination, the gross weight imposed on the highway by any group of 2 or more consecutive axles of the vehicle or vehicle combination may not exceed the maximum gross weights in the following table for each of the respective distances between axles and the respective numbers of axles of a group: [See Figure 348.15 (3) (g) following]
(h) Notwithstanding pars. (a) to (c) and (g), sub. (4), and ss. 348.17 and 349.16, in the case of a vehicle operated by an engine fueled primarily by natural gas, the gross weight of the vehicle, and the gross weight imposed on the highway by the wheels of any one axle or axle group of the vehicle, may exceed the applicable weight limitation specified in pars. (a) to (c) or (g) or posted as provided in s. 348.17 (1) by not more than 2,000 pounds, or an amount equal to the difference between the weight of the natural gas tank and fueling system and the weight of a comparable diesel tank and fueling system, whichever is less.
(4) Notwithstanding the possibility of increased weight on a particular wheel or axle or group of axles due to practical operating problems, including, but not limited to, accumulation of snow, ice, mud or dirt, the use of tire chains or minor shifting of load, the maximum weights set forth in sub. (3) include absolutely all weights allowable.
(5) For enforcement of weight limitations specified by this chapter the gross weight, measured in pounds, imposed on the highway by any wheel or any one axle or by any group of 2 or more axles shall be determined by weighing the vehicles and load, either by single draft or multiple draft weighing on certified stationary scales or on portable scales in good working order which are tested in comparison to certified stationary scales within 180 days immediately prior to any weighing operation by the department of agriculture, trade and consumer protection or other authorized testing agencies for accuracy to within standard accepted tolerances. The weighing operation shall be performed in accordance with and under conditions accepted as good weighing technique and practice. In multiple draft weighing the sum of the weight of respective components shall be used to establish the weight of a combination of the components. It is recognized that the weight, determined in accordance with methods prescribed in this chapter, includes all statutory weights and represents the momentary load force or reaction imposed on the scale at the time of weighing. Such weights include any variation due to the following factors:
(a) Positioning or tilt of the vehicle on the scale platform and adjacent bearing surface;
(b) Momentary position of axle centers with respect to wheel bearings and vehicle body;
(c) Temporary distribution of loading on the wheel or axle; and
(d) Miscellaneous variable factors of spring flexure, shackle friction, clutch engagement, brake pressure, tire compression and other variable factors.
(5m) The distances between axles and between the foremost and rearmost of a group of axles shall be measured between axle centers to the nearest even foot, and when a fraction is exactly one-half foot, the nearest larger whole number shall be used.
(5r) Irrespective of sub. (5), in determining overweight under sub. (3) the results of weighing by means of either portable scales or certified stationary scales shall be admissible as evidence.
(6) At any state weighing scale where a vehicle is found overloaded, the driver may request its reweighing at the same scale. Upon reweighing the state officials shall supply the tabulated weight ticket to the driver. All weight tickets for any vehicle shall be supplied to the court in case the matter goes to trial.
(8) Unless the department provides otherwise by rule, any axle of a vehicle or combination of vehicles which does not impose on the highway at least 8 percent of the gross weight of the vehicle or combination of vehicles may not be counted as an axle for the purposes of sub. (3) (c) and (g).
(9)
(a) Except as provided in pars. (c), (cm), (e), and (f), the increased weight allowance for implements of husbandry and agricultural commercial motor vehicles under sub. (3) (b) and (g) applies in lieu of, not in addition to, any other increased weight allowance for implements of husbandry or agricultural commercial motor vehicles authorized under this chapter.
(b) Except as provided in par. (e), the maximum gross weight for an implement of husbandry or agricultural commercial motor vehicle operated on a highway without a permit may not exceed 92,000 pounds. Except as provided in par. (e), the maximum gross weight for a 2-vehicle combination transporting by trailer or semitrailer an implement of husbandry or agricultural commercial motor vehicle to or from a farm-related destination, and operated on a highway without a permit, may not exceed 92,000 pounds.
(c)
1. Notwithstanding sub. (3) (a), (b), (c), and (g), there is no weight limitation per wheel, axle, or group of axles for an implement of husbandry that is an empty potato harvester if, subject to subd. 2., the potato harvester is accompanied by one or more escort vehicles operating with hazard lights activated, except that such a potato harvester is subject to any weight limitation posted as provided in s. 348.17 (1). Except as provided in par. (e), a potato harvester is subject to the maximum gross weight limitation for implements of husbandry specified in par. (b).
2. A potato harvester is not required to be accompanied by any escort vehicle under subd. 1. if the potato harvester is traveling to or from a farm-related destination and is operated on the highway for a distance of 0.5 miles or less.
(cm)
1. Notwithstanding sub. (3) (a), (b), (c), and (g), there is no weight limitation per wheel, axle, or group of axles for a 2-vehicle combination transporting by trailer or semitrailer an empty potato harvester to or from a farm-related destination if, subject to subd. 2., the 2-vehicle combination is accompanied by one or more escort vehicles operating with hazard lights activated, except that such a 2-vehicle combination is subject to any weight limitation posted as provided in s. 348.17 (1). Except as provided in par. (e), such a 2-vehicle combination transporting a potato harvester is subject to the maximum gross weight limitation for 2-vehicle combinations transporting implements of husbandry specified in par. (b).
2. A 2-vehicle combination transporting a potato harvester is not required to be accompanied by any escort vehicle under subd. 1. if the potato harvester is being transported to or from a farm-related destination on a highway for a distance of 0.5 miles or less.
(d) The increased weight allowance for implements of husbandry and agricultural commercial motor vehicles under sub. (3) (b) and (g) does not apply on any highway that is a part of the national system of interstate and defense highways, except for the I 41 corridor. The increased weight allowance for 2-vehicle combinations transporting implements of husbandry or agricultural commercial motor vehicles under sub. (3) (b) and (g) does not apply on any highway that is a part of the national system of interstate and defense highways.
(e)
1. Notwithstanding par. (c) and sub. (3) (a), (b), (c), and (g), but subject to subd. 3., there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation, for an implement of husbandry or agricultural commercial motor vehicle while being operated or transported by an implement dealer or farmer for purposes of delivery, repair, or servicing of the implement of husbandry or agricultural commercial motor vehicle if the implement of husbandry or agricultural commercial motor vehicle is being operated or transported under either of the following circumstances:
a. Directly from a farmer’s owned or leased land to the business location of an implement dealer that is within a 75-mile radius of the farmer’s owned or leased land.
b. Directly from the business location of an implement dealer to a farmer’s owned or leased land that is within a 75-mile radius of the implement dealer’s business location.
2. Notwithstanding par. (c) and sub. (3) (a), (b), (c), and (g), but subject to subd. 3., there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation, for an implement of husbandry described in s. 340.01 (24) (a) 1. b., or for an agricultural commercial motor vehicle used as described in s. 340.01 (1o) (e) 1., that is traveling to or from a farm-related destination and is operated on the highway for a distance of 0.5 miles or less.
3. Subdivisions 1., 2., and 4. do not apply on any highway that is posted with a weight limitation as provided in s. 348.17 (1). Subdivision 1. does not apply on any highway that is a part of the national system of interstate and defense highways, except for the I 41 corridor. Subdivision 2. does not apply on any highway that is a part of the national system of interstate and defense highways, except for an implement of husbandry operated on the I 41 corridor. Subdivision 4. does not apply on any highway that is a part of the national system of interstate and defense highways.
4. Notwithstanding par. (cm) and sub. (3) (a), (b), (c), and (g), but subject to subd. 3., there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation, for a 2-vehicle combination transporting by trailer or semitrailer an implement of husbandry described in s. 340.01 (24) (a) 1. b. or agricultural commercial motor vehicle used as described in s. 340.01 (1o) (e) 1. to or from a farm-related destination, on a highway for a distance of 0.5 miles or less.
(f)
1. Notwithstanding par. (c) and sub. (3) (a), (b), (c), and (g), and except as provided in subd. 3. and par. (e), there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation other than that specified in par. (b), for an implement of husbandry described in s. 340.01 (24) (a) 1. b., or for an agricultural commercial motor vehicle used as described in s. 340.01 (1o) (e) 1., being operated on a highway that is not designated under subd. 2. a.
1m. Notwithstanding par. (cm) and sub. (3) (a), (b), (c), and (g), and except as provided in subd. 3. and par. (e), there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation other than that specified in par. (b), for a 2-vehicle combination transporting by trailer or semitrailer an implement of husbandry described in s. 340.01 (24) (a) 1. b. or agricultural commercial motor vehicle used as described in s. 340.01 (1o) (e) 1. to or from a farm-related destination, on a highway that is not designated under subd. 2. a.
2.
a. The governing body of a municipality or county may, by resolution or ordinance, designate highways under the municipality’s or county’s jurisdiction, for maintenance purposes, on which the statutory weight limits prescribed under this section, other than this paragraph, for implements of husbandry or agricultural commercial motor vehicles apply to implements of husbandry described in s. 340.01 (24) (a) 1. b., and to agricultural commercial motor vehicles used as described in s. 340.01 (1o) (e) 1., that are operated or transported on the highway and to 2-vehicle combinations transporting them. If a resolution or ordinance is adopted under this subd. 2. a., any weight limit resulting from the resolution or ordinance is considered to be a weight limit imposed by this chapter and any violation is considered to be a violation of the applicable weight limits prescribed under this section.
b. For a resolution or ordinance under this subdivision to be effective in any calendar year, the resolution or ordinance must be adopted on or before November 30 of the prior year. A resolution or ordinance adopted under this subdivision shall be valid for at least one calendar year. No amendment to a resolution or ordinance is effective in a calendar year unless the amendment was adopted on or before November 30 of the prior year.
c. No later than January 20 of the year after it adopts or amends a resolution or ordinance under this subdivision, each municipality or county that designates highways under subd. 2. a. shall forward to the department a copy of the resolution or ordinance, and the department shall publish the resolution or ordinance on the department’s Internet site.
3. Subdivisions 1. and 1m. do not apply on any highway that is a state trunk highway or that is posted with a weight limitation as provided in s. 348.17 (1).
(10)
(a) Notwithstanding sub. (3) (a), (b), and (c), but subject to par. (b), there is no weight limitation per wheel, axle, or group of axles, and no gross weight limitation, for skidders, forwarders, harvesters, and wheeled feller bunchers operated for logging purposes at times other than hours of darkness and operated unladen on the highway for a distance of 0.5 miles or less.
(b) Paragraph (a) does not apply on any highway that is posted with a weight limitation as provided in s. 348.17 (1) or that is a part of the national system of interstate and defense highways.
Source: WI Statutes (Official Site)URL: https://docs.legis.wisconsin.gov/document/statutes/348.15Fetched: 10/7/2026