65 ILCS 5/11-40-2b
No municipality with fewer than 1,000,000 inhabitants may regulate or prescribe safety requirements for motor vehicles used to transport for hire students to or from a school where students are in attendance. This Section does not prohibit any municipality from which such vehicles originate their operation from registering such vehicles or requiring the purchase of vehicle stickers where no regulatory requirements are imposed.
This Section is a limitation on the power of home rule municipalities with fewer than 1,000,000 inhabitants, and the regulation and prescribing of safety requirements for such motor vehicles is declared an exclusive State function in municipalities with fewer than 1,000,000 inhabitants under Article VII, Section 6, paragraph (h) of the Constitution.
65 ILCS 5/11-40-2b