70 ILCS 1905/5
As soon as possible after the filing in the office of the recorder of the resolution organizing the Railroad Terminal Authority, the mayor of the city shall appoint 7 commissioners. One of the persons so appointed as Commissioner shall be designated by the mayor as chairman of the Board of Commissioners and shall be appointed for a term of 6 years, and the remaining commissioners shall be appointed for initial terms of 1, 2, 3, 4, 5 and 6 years. The appointment of the Chairman of the Board of Commissioners and the other 6 members thereof shall be subject to the approval of the city council of the city. Upon the approval of such appointments, as aforesaid, the persons so appointed shall constitute the Board of Commissioners of the Railroad Terminal Authority and upon taking the oath of office as hereinafter provided shall be deemed to have qualified and be empowered to exercise the powers and authority prescribed in this Act.
At the expiration of the term of each of the Commissioners, including the Chairman, and of each succeeding Commissioner, or in the event of a vacancy, resignation, removal or refusal to act, the Mayor of the city shall appoint a successor, in the same manner as hereinabove provided for the appointment of initial members, to hold office in the case of a vacancy occurring for whatever reason for the unexpired term, or in the case of expiration, for a term of 6 years, and until his successor is appointed and has qualified. Any commissioner may be appointed to succeed himself.
70 ILCS 1905/5