Agricultural Safety & Health
Research, Outreach, and Education to improve the health, safety, and well-being of agriculture
Aerial view of the Arlington ARS taken from a drone, with a large farm building in the foreground and fields stretching in the distance

Ag CMV Information

According to s. 340.01 (1o) Wis. Stats.:

(1o) “Agricultural commercial motor vehicle” means a commercial motor vehicle to which all of the following apply:

  1. The vehicle is substantially designed or equipped, or materially altered from its original construction, for the purpose of agricultural use.
  2. The vehicle was designed and manufactured primarily for highway use.
  3. Unless the vehicle was manufactured prior to 1970, the vehicle was manufactured to meet federal motor vehicle safety standard certification label requirements as specified in 49 CFR 567.
  4. The vehicle is used exclusively in the conduct of agricultural operations.
  5. The vehicle is being used in any of the following way
    1. For directly distributing feed to livestock or for directly applying fertilizer (but not manure), lime, spray or seeds to a farm field (Category 1)
    2. For assisting another vehicle directly harvesting farm products by receiving farm products as they are harvested or for assisting another vehicle directly planting potatoes by delivering seed potatoes to the planter.(Category 2)
    3. For directly applying manure to a farm field or for off-loading manure if field conditions do not permit application by the vehicle directly to the field. (Category 3)

For vehicles exceeding these dimensions, see Permit section.

Width

  • Width limit is 10 feet including attachments or accessories
    • Exception: Pesticide sprayers, lime and fertilizer spreaders (not including manure) with extending tires, fenders and fender flares may not exceed 12 feet in width.
  • Ag CMVs over 8 feet 6 inches may not operate on interstate highways.
  • If an Ag CMV being operated or trailered exceeds width limits, see Permit section.

Height

  • The maximum height is 13 feet 6 inches.

Length

  • Single vehicle
    • 45 feet
  • Two vehicle combination – one towed unit driven by a power unit
    • 70 feet
  • Three vehicle combination – two towed units drawn by a power unit.
    • No more than 100 feet with speed restriction of 25 mph or less or 70 feet at a speed greater than 25 mph.
    • Towed units being drawn by a motor truck, truck tractor, or agricultural commercial motor vehicle must be empty. “Empty” means less than 20 percent full. [s. 348.08 (1) (d) Wis.Stats.]
  • An Ag CMV may be transported on a trailer or semi-trailer at the same  length limits as if being driven on the highway from to and from a farm-related destination.

IoH/Ag CMV Maximum Weight Limits table (s. 348.15 (3) (g) Wis. Stats.) applies. This allows for a maximum single axle weight of 23,000 pounds and a gross vehicle weight of 92,000 pounds dependent upon on number of axles and axle spacing.

Exemptions:

  • Ag CMV – Category 1 that directly distribute feed to livestock or directly apply fertilizer (but not manure), lime, spray, or seeds to a farm field are exempt from:
    • axle weight limits on local roads unless local government authority passes ordinance or resolution limiting Ag CMV axle weight.
    • gross vehicle weight and axle weight limits when operating between fields and operated on the highway for a distance of 1/2 mile or less or if it is transported by a 2 vehicle combination via trailer or semitrailer from farm to field, field to field, farm to farm.
    • Class B road posting [s. 348.16 (2) Wis. Stats.] but MUST OBEY seasonal or special weight postings and bridge postings [s. 348.17 Wis. Stats.].
  • Ag CMVs traveling for delivery, service, repair by dealer or farmer within 75-mile radius of business or farm is exempt from gross vehicle weight and axle weight limits. Also exempt from Class B road postings. MUST OBEY seasonal or special weight posting or bridge posting [s. 348.17 Wis. Stats.].

No Fee Permit may be required if gross vehicle weight or axle weight is greater than the IoH/Ag CMV Maximum Weight Limit table. See Permits.

Operators must abide by seasonal or other special road postings and bridge postings.

Weight limits do not apply on Interstate highways except for the I 41 corridor. [s. 348.15 (9) (d) Wis. Stats.]

Wisconsin crops need to be harvested and transported from field to farm or field to market. Wisconsin law allows for commercial motor vehicles (CMV), registered at a gross weight of 50,000 pounds or more, to operate by not more than 15 percent over weight limit based on the s. 348.15 (3) (c) weight table.

2015 Wisconsin Act 235, effective March 3, 2016, amended the start date for seasonal weight limit from September 1 to August 1 each year.

This weight increase can not be combined with weight limits for IoH or Ag CMVs.

s. 348.17 (5) (a) Wis. Stats.
    1. From August 1 to December 31 of each year, no permit shall be required for the transportation of corn, soybeans, potatoes, vegetables, or cranberries from the field to storage on the grower’s owned or leased land, from the field to initial storage at a location not owned or leased by the grower, or from the field to initial processing in a vehicle or combination of vehicles that exceeds the weight limitations under s. 348.15 by not more than 15 percent and that satisfies all of the following:
      1. Has a registered gross weight of 50,000 pounds or more.
      2. Is a motor truck, farm truck, road tractor, truck tractor, or farm truck tractor or such a vehicle combined with a semitrailer, trailer, or farm trailer, when the vehicle or combination is a commercial motor vehicle operated on a highway.
    2. This subsection does not apply to the national system of interstate and defense highways, except for the I 41 corridor and that portion of I 39 between USH 51 and I 90/94.
    1. From September 1 to December 31 of each year, no permit shall be required for the transportation of manure to or from a farm in a vehicle or combination of vehicles that exceeds the weight limitations under s. 348.15 by not more than 15 percent and that satisfies any of the following:
      1. Has a registered gross weight of 50,000 pounds or more.
      2. Is a motor truck, farm truck, road tractor, truck tractor, or farm truck tractor or such a vehicle combined with a semitrailer, trailer, or farm trailer, when the vehicle or combination is a commercial motor vehicle operated on a highway.
    2. This subsection does not apply to the national system of interstate and defense highways, except for the I 41 corridor.

An Ag CMV being trailered to or from a farm-related destination may operate at the same weight limits as if being driven on the highway. No Fee Permit applies to exceed gross vehicle weight or axle weight limits. Ag CMV Category 1 retain weight exceptions if transported by a 2-vehicle combination via trailer or semi-trailer to or from a farm-related destination.

The maximum length limits for an Ag CMV being transported would be determined the maximum length for Ag CMV vehicle or vehicle combination. No Fee Permit applies to exceed length.

Ag CMVs over 8 ft. 6 in. can be transported by trailer or semi-trailer during hours other than hours of darkness but limited to 8 ft. 6 in. during hours of darkness. Ag CMVs being trailered over 8 feet 6 inches in width are not allowed on the Interstate highway unless operated by permit.

Any Ag CMV being trailered wider than 8 ft 6 in requires 2 flashing amber warning lights visible front and rear at the extremities of the Ag CMV. [s. 348.09 (3) (b) Wis. Stats.]

An Ag CMV is exempt from registration under s. 341.05 (17) Wis. Stats.

An Ag CMV Self-Certification form (MV2580) is available on the WisDOT website at AgVehicles.DOT.wi.gov. MV2580 is not a required form but provides a reference for operators and law enforcement.

A registered vehicle may also operate under the Ag CMV definition without needing to remove its registration plates.

If my Ag CMV isn’t registered, can I use dyed fuel?