605 ILCS 5/4-221
To the extent allowed by federal law, the Department specifications shall allow the use of recycled asphalt roofing shingles received from facilities authorized to process asphalt roofing shingles for recycling into asphalt pavement in accordance with (i) permits issued pursuant to Section 39 of the Environmental Protection Act or (ii) beneficial use determinations issued pursuant to Section 22.54 of the Environmental Protection Act. In creating the mix designs used for construction and maintenance of State highways, it shall be the goal of the Department, through its specifications, to maximize the percentage of recycled asphalt roofing shingles and binder replacement and to maximize the use of recycled aggregates and other lowest-cost constituents in the mix so long as there is no detrimental impact on life-cycle costs.
605 ILCS 5/4-221