The Peoria County Highway Department utilizes seal coating and tilling to maintain Peoria County Highways. Additionally, local townships and municipalities utilize the Department's services for seal coating and tilling.
Tilling is a process of grinding and mixing the existing road surface and base. Additional gravel is then added to the existing material and all the materials are compacted and graded. The process takes several days and traffic is also used to help compact the gravel. Once the gravel is compacted, the road is graded one more time, and seal coating of the road occurs.