605 ILCS 5/5-105
Temporary closings of county highways, or changes in highways making up a part of the county highway system, including additions to and deletions from such system, may be made by resolution of the county board, subject to the approval of the Department. Highways permanently removed from the county highway system which do not become part of the State highway system shall become part of the township and district road system if in a rural area, or the municipal street system if in a municipality. Such permanent changes shall be indicated on the map provided for by Section 5--103 of this Code or a corrected map may be substituted therefor. The provisions of this Section do not apply to the vacation or relocation of a county highway or part of it pursuant to Sections 5--107, 5--109 or 5--110 of this Code. However, a change occasioned by the vacation or relocation of a county highway or part of it pursuant to Sections 5--107, 5--109 or 5--110 of this Code shall be indicated on the map provided for by Section 5--103 in the same manner as changes made under this Section.
605 ILCS 5/5-105