220 ILCS 5/4-302
The Commission shall cooperate with the Regional Transportation Authority created pursuant to the "Regional Transportation Authority Act", enacted by the 78th General Assembly, in the exercise of the powers of the Authority as provided in that Act.
Transportation Agencies which have any purchase of service agreement with a Service Board as provided in the "Regional Transportation Authority Act" shall not be subject to this Act as to any public transportation which is the subject of such agreement. Any service and business exempted from this Act pursuant to this Section shall not be considered "intrastate public utility business" as defined in Section 3-120 of this Act.
No contract between any Transportation Agency and the Authority or a Service Board or acquisition by the Authority or a Service Board of any property, including property of a Transportation Agency pursuant to and as defined in the Regional Transportation Authority Act, shall, except as provided in such Act, be subject to the supervision, regulation or approval of the Commission.
In the event a Service Board shall determine that any Public Transportation service provided by any Transportation Agency with which that Service Board has a Purchase of Service Agreement is not necessary for the public interest and shall for that reason decline to enter into any Purchase of Service Agreement for such particular service, all pursuant to and as defined in such Regional Transportation Authority Act, then the discontinuation of such service by such Transportation Agency shall not be subject to the supervision, regulation or approval of the Commission.
220 ILCS 5/4-302