50 ILCS 750/6
All systems shall be designed to meet the specific requirements of each community and public agency served by the system. Every system shall be designed to have the capability to direct dispatch or to transfer in response to emergency calls. The General Assembly finds and declares that the most critical aspect of the design of any system is the procedure established for handling a telephone request for emergency services.
In addition, to maximize efficiency and utilization of the system, all pay telephones within each system shall enable a caller to dial "9-1-1" for emergency services without the necessity of inserting a coin. This paragraph does not apply to pay telephones located in penal institutions, as defined in Section 2-14 of the Criminal Code of 2012, that have been designated for the exclusive use of committed persons.
50 ILCS 750/6