Wisconsin Department of Transportation

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Agricultural equipment and vehicles

Tractor roadway sign

Agricultural equipment is getting larger and heavier, which helps in more efficient farm production, but it can also impact pavement and road structures. Thatís why the Wisconsin Department of Transportation, in partnership with the Wisconsin Department of Agriculture, Trade and Consumer Protection, convened the Implements of Husbandry (IoH) Study Group. It involved over 20 stakeholders representing various transportation and farm organizations, equipment manufacturers, law enforcement, local officials and the University of Wisconsin-Madison/Extension.

Following months of research and discussion, the group presented preliminary recommendations at a series of town hall meetings. Feedback was also gathered through an online survey and letter and email submissions.

public hearing photo 1

After analyzing the responses, the IoH Study group amended its recommendations and submitted them to the Wisconsin State Legislature for their consideration. The study groupís final recommendations include:

  • Create a clearer, simpler definition of IoH to reflect todayís agricultural equipment, which would also include a definition for commercial motor vehicles used exclusively for agricultural operations.
  • Require all IoH that cross over the centerline of the roadway during operation to meet the lighting and marking standards of the American Society of Agricultural Engineers (ASAE S279).
  • Create a 60-foot limit for a single IoH and a 100-foot limit for combinations of two IoH. For combinations of three IoH the limit is 70 feet, but a three IoH combination may operate at lengths exceeding 70 feet, to a limit of 100 feet, at a speed no greater than 20 miles per hour
  • Create a new IoH weight limit which is up to 15 percent weight allowance more than currently established by the federal bridge formula. This equates to a maximum single axle weight of 23,000 pounds and a maximum gross vehicle weight of 92,000 pounds except where posted and during periods of spring thaw.
  • Require written authorization to exceed weight limits. On an annual basis IoH operators may submit a travel or route plan and request written authorization to exceed the weight limit from the maintaining authority of the roadways. A nominal fee may be charged and additional conditions may be set by each maintaining authority. IoH vehicles operating in excess of the 15 percent allowance will be fined for the amount in excess of standard gross motor vehicle weight or individual axle weight.
  • Support exploration of best practices to assist in reducing the wear of roadways and structures. This includes the development of emerging innovations and best practices in manure management.
  • Develop further training requirements for the operation of large IoH equipment. Age requirements are to remain as presently allowed in statute, but the group recommends developing advanced training for operating larger and heavier IoH.

The Study Group also sees the need to advance these issues to groups such as the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) to encourage the development of national standards. This approach will foster additional research where needed and encourage manufacturers to develop more road compatible equipment.

For a detailed list of the final recommendations please reference the IoH Group Phase II Addendum Report.

IoH facts and studies

Questions and comments about the report can be sent to: IoHStudyFeedback@dot.wi.gov



Large and heavy agricultural equipment and vehicles impact public roadways and structures.  Town hall meetings are seeking feedback on recommendations to restore the balance between roads and agricultural equipment.

Posted culvert photo

Broken pavement

Overhead power lines

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