The Macoupin County Highway Department is responsible for the planning, design, construction, and maintenance of the 222 miles of county highways and the 41 bridges on the county highway system.

The Highway Department provides technical assistance to all 26 township highway commissioners for their 1,080 miles of road and 144 bridges. The department is also the lead agency for all township projects constructed or maintained with state Motor Fuel Tax funding. In addition, the Highway Department keeps records of contracts, purchases of materials, machinery, etc. and administers all highway and bridge funds for the county. See explanation of funds here.

The staff works closely with local citizens and agencies, as well as the Illinois Department of Transportation and the Federal Highway Administration.