605 ILCS 5/3-105
Except as otherwise provided in the Treasurer as Custodian of Funds Act, all money received by the State of Illinois from the federal government for aid in construction of highways shall be placed in the Road Fund in the State treasury . For the purposes of this Section, money received by the State of Illinois from the federal government under the Recreational Trails Program for grants or contracts obligated on or after October 1, 2017 shall not be considered for use as aid in construction of highways, and shall be placed in the Park and Conservation Fund in the State treasury.
Whenever any county having a population of 500,000 or more inhabitants has incurred indebtedness and issued Expressway bonds as authorized by Division 5-34 of the Counties Code and has used the proceeds of such bonds for the construction of Expressways in accordance with the provisions of Section 15d of "An Act to revise the law in relation to roads and bridges", approved June 27, 1913, as amended (repealed) or of Section 5-403 of this Code in order to accelerate the improvement of the National System of Interstate Highways, the federal aid primary highway network or the federal aid highway network in urban areas, the State shall appropriate and allot, from the allotments of federal funds made available by Acts of Congress under the Federal Aid Road Act and as appropriated and made available to the State of Illinois, to such county or counties a sum sufficient to retire the bonded indebtedness due annually arising from the issuance of those Expressway bonds issued for the purpose of constructing Expressways in the county or counties. Such funds shall be deposited in the Treasury of such county or counties for the purpose of applying such funds to the payment of the Expressway bonds, principal and interest due annually, issued pursuant to Division 5-34 of the Counties Code.
605 ILCS 5/3-105