605 ILCS 5/5-605.1

The county board of any county may by ordinance and without referendum, issue bonds of the county for the purpose of constructing bridges under any of Sections 5-501 through 5-503 if the county first secures the approval of the Department for the bridge construction project in the manner provided by Section 5-403 for approval of highway construction projects. Such bonds must mature within 5 years and the principal and interest on those bonds must be payable, as provided in Section 5-701.4, from motor fuel tax money allotted to the county.