The Piatt County Highway Department is responsible for the supervision of 85 miles of designated county highways. In addition to the county roads, the Department also assists the eight townships in Piatt County by providing engineering work and administration of their Motor Fuel Tax funds and the Township Bridge Program funds. The Piatt County Highway Department is also responsible for inspection of all 189 structures over 20 feet in length located in the County.

The mission of the Piatt County Highway Department is to provide and manage with a professional work force the best highway system within available resources. This highway system must meet the needs of the public and sustain and enhance the environment and economic climate of Piatt County.