Roadside Vegetation Management

The Lake County Division of Transportation (LCDOT) manages roadside vegetation along approximately 300 miles of County roads and 65+ miles of bike paths throughout Lake County. This vegetation plays an important role in the safety and aesthetics of Lake County roadsides. The composition of the vegetation varies greatly from grasslands, prairie, trees, and landscape plantings.  


Roadside vegetation is managed to provide drivers with a clear view of approaching vehicles and other hazards. Roadsides are designed to allow stormwater to quickly drain off of the road and are appropriately planted with vegetation to prevent erosion. Roadside vegetation can also be used to control blowing and drifting snow and signal drivers to slow down in urban areas. 

Vegetation control methods

Along most roadsides, there is a combination of vegetation types that may require different maintenance techniques. LCDOT uses a variety of methods and combinations of these methods to achieve effective vegetation control. 

Dilleys and Wadsworth Roundabout

Biological control 
The use of natural plants reduces the growth and establishment of invasive and noxious weeds. LCDOT works in collaboration with the Lake County Forest Preserves and Stormwater Management Commission to use native plantings on roadsides when possible. In addition to combating weeds, native plants can protect and maintain pollinator habitats, help with drainage as their deep root structures help to loosen the soil and promote the infiltration of stormwater.

Native plantings can also improve water quality as they absorb and remove some of the pollutants from the stormwater.  

Detention Basin LCDOT

Detention Basins
Detention basins hold stormwater runoff from adjacent parking lots and roadways. They may feature native vegetation to enhance water quality and provide natural habitat. Basins have been installed with several projects and LCDOT even has one in front of its admin building in Libertyville that features a bio-swale and bio-retention pond along with native vegetation. 

Mowing before and after

Summer mowing operations typically begin in May. LCDOT prioritizes sight distance over aesthetics. Typically, the first cut is finished in early July, and once the hotter and drier summer months arrive, slower growth makes the second and third rounds of work much easier.


LCDOT makes a conscious effort to limit its use of herbicides along the right-of-way. Within LCDOT, we limit herbicide use to control weed and grass growth primarily on guardrails and fences. They are used to control dangerous or unwanted vegetation such as buckthorn. LCDOT requires herbicide applicators performing work on the County’s right-of-way to maintain a current license, issued by the State of Illinois, for Applicators and Sprayers of Herbicide onto Roadway Rights of Ways. 

Tree Management

Trees serve an important function along LCDOT's transportation system. Trees can provide countless environmental benefits including, but not limited to:

  • Improved air and water quality
  • Removal of carbon dioxide from the atmosphere
  • Increased pollinator habitat
  • Increased wildlife habitat
  • Provide visual screening of the roadway for adjacent properties

Besides providing environmental and other functional benefits, trees also provide aesthetic value for those traveling on our roads. While many trees on LCDOT's roadsides occur naturally, in other instances, trees are incorporated into the roadside landscape.  

If not properly managed and cared for, trees can also cause problems for the traveling public. Trees and other woody vegetation must be properly managed at all times, including removal, to avoid becoming hazardous to motorists and pedestrians or interfering with LCDOT maintenance operations. Trees are also removed from LCDOT rights-of-way due to insect and disease issues, and from storms that damage trees. Utility companies also trim and remove trees within the right-of-way. 

LCDOT works to avoid tree impacts wherever possible and looks for opportunities to plant replacement trees along corridors, near detention basins, local parks, and other locations. As we continue to make necessary improvements to address safety, mobility, and non-motorized connectivity, tree removal for construction projects may be required for new projects. LCDOT may clear trees for projects between Oct. 1 and March 31 in accordance with the Illinois Department of Transportation's guidance to protect the endangered northern long-eared bat. The guidance still allows for tree clearing at all times of the year if there are safety concerns

Report A Concern

Inform LCDOT of concerns about sight distance, dead or diseased trees along the County right-of-way, or anything else related to LCDOT roadside vegetation management using this form. 

Wetland mitigation Bank

Caption: in 2019, LCDOT worked with the Lake County Forest Preserves to construct a new wetland mitigation bank at Buffalo Creek Forest Preserve. This project returned former farm fields to a sustainable natural condition. More than 25 acres of wetlands were created, and a new section of path was added that is part of Buffalo Creek Forest Preserve’s path system.