Wisconsin Department of Transportation

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Implement of Husbandry (IoH) new size and weight information

View Wisconsin Act 377 definitions for IoH

Width

  • No width limitations however additional lighting and marking requirements are effective Nov. 1, 2015.
  • Also applies for IoH being operated or transported for delivery, service, or repair by dealer or farmer within 75-mile radius of business or farm.

Height

  • No height limitations.
  • Operator of IoH remains responsible for ensuring safe clearance of any overhead obstructions.

Length

  • Single vehicle
    • 60 feet
    • No-Fee permit may be required over 60 feet
  • Two vehicle combination
    • 100 feet
    • No-Fee permit may be required over 100 feet
  • Three vehicle combination
    • No more than 100 feet with speed restriction of 25 mph or less OR 70 feet at a speed greater than 25 mph.
    • No-Fee permit may be required if exceeding 100 feet in length.
    • Towed units being drawn by a motor truck, truck tractor, or Ag CMV must be empty. “Empty” means less than 20 percent full.
    • Length limits also apply to IoH being operated or transported for delivery, service, repair by dealer or farmer within 75-mile radius of business or farm. Beyond these dimensions, standard commercial (single or annual) permits are required.

To operate at lengths greater than those listed above, you may need to apply for an IoH/Ag CMV Permit from the maintaining authority for the roads on which you are proposing to operate.

Weight

  • New maximum IoH/Ag CMV weight limits table applies. This allows for a maximum single axle weight of 23,000 pounds and a gross vehicle weight of 92,000 pounds dependent on number of axles and axle spacing.
  • No-Fee permit may be required if gross vehicle weight or axle weight is greater than the IoH weight table.
  • All operators must abide by seasonal or other special postings.
  • IoH weight limits do not apply on Interstate highways. §348.15 (9)(c)2.(d)
  • Exemptions
    • Empty potato harvester is exempt from axle weight limit. Also exempt from Class B road postings.
    • Category B is:
      • Exempt from axle weight limits unless local road authority passes ordinance or resolution limiting self-propelled IoH axle weight.
      • Exempt from 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.
      • Exempt from Class B road postings.
    • IoH 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.

To operate at weights greater than those listed above, you may need to apply for an IoH/Ag CMV Permit from the maintaining authority for the roads on which you are proposing to operate.

Other Changes

  • Limits on hours of operation are eliminated.
  • As of Nov. 1, 2015:
    • All vehicles exceeding 15-feet must have front and rear warning lights on and reflective material visible anytime on highway, unless operating in daylight with an escort vehicle and two orange or red flags marking the outside edges.
    • All vehicles exceeding 22 feet must have an escort vehicle with hazard flashers activated. Escort is not required for incidental travel of 1/2 mile or less.

IoH dimensions

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