Mowing Wisconsin's roadsides

The Wisconsin State Highway System includes about 11,800 miles of numbered state, federal and Interstate highways. In the 1950’s reflecting the fiscal impracticality of mowing the entire highway right of way the natural roadsides philosophy was adopted. This philosophy encourages minimal mowing with the use and preservation of native vegetation when possible. 

In 2009, routine maintenance work priorities were further redefined in response to budgetary constraints. Consistent with the natural roadsides philosophy, the mowing policy was curtailed to safety locations such as vision corners when needed and roadside shoulder cuts to once a season.

In the same year, 2009, Invasive Species Rule (NR 40) was passed. This rule lists and regulates a number of non-native invasive species and requires control of these invasive species. To accomplish this control, mowing completion dates were included as part of the philosophy.

In 2014 the mowing policy was revised to add an urban mowing component. The urban mowing policy is used in combination with the natural roadsides philosophy and allows for increased mowing frequency in specified urban areas to produce a closer match in vegetation management to adjacent land uses.

The actual mowing is done by county highway crews.

General mowing policy goals

  • Support public safety, especially at intersections and curves
  • Provide safe areas for vehicles to pull off roads in emergencies, and clear recovery zones for errant vehicles that leave the roadway
  • Balance the need to manage invasive species with overall aesthetics and budgetary limitations
  • Protect wildlife, preserve and encourage native wildflowers and grasses
  • Preserve Wisconsin's natural beauty


Trans 280, Roadside Vegetation Management, establishes uniform procedures to maintain, enhance and protect roadside vegetation and ecology (maintenance of trees, shrubs, grasses and forbs).

NR 40 Invasive Species Identification, Classification and Control. This is the Department of Natural Resources Administrative Code.


Contact the Region Maintenance Supervisors for the county you have a mowing activity question about.  Contact the Bureau of Highway Maintenance landscape architects for questions regarding mowing policies.