605 ILCS 5/4-201.4

To enter into contracts covering all matters and things incident to the location, relocation, construction, repair and maintenance of State highways; including, subject to approval by the Illinois Commerce Commission, agreements with a railroad or railway company or other public utility concerning a relocation of its line, tracks, wires, poles, pipes or other facilities, where the same are not then located in a public street or highway, and such relocation is necessary as an incident to the construction of a new State highway or to the relocation, reconstruction, extension, widening, straightening, alteration, repair, maintenance or improvement of an existing State highway (including extensions of a new or existing State highway through or into a municipality upon a new or existing street). Nothing contained in this Section shall be construed as requiring the Department to furnish site or right-of-way for railroad or railway lines or tracks or other public utility facilities required to be removed from a public street or highway.