30 ILCS 178/5-10

(a) It is known that transportation funding is generated by several transportation fees outlined in Section 2 of the Motor Fuel Tax Act, Section 5-1035.1 of the Counties Code, Section 8-11-2.3 of the Illinois Municipal Code, and Sections 3-805, 3-806, 3-815, 3-818, 3-819, 3-821, and 6-118 of the Illinois Vehicle Code. (b) The proceeds of the funds described in this Act and all other funds described in Section 11 of Article IX of the Illinois Constitution are dedicated to transportation purposes and shall not, by transfer, offset, or otherwise, be diverted by any local government, including, without limitation, any home rule unit of government, to any purpose other than transportation purposes. This Act is declarative of existing law.