625 ILCS 5/11-213
In the absence of a law enforcement officer or a representative of the highway agency having jurisdiction over the highway, an officer of a fire department, in the performance of his or her official duties, has the authority to close to traffic a highway, or a lane or lanes of a highway, as necessary to protect the safety of persons or property. In order to promote the safe implementation of this Section, the fire department officer shall utilize an official fire department vehicle with oscillating, rotating, or flashing lights in accordance with Section 12-215 of this Code and proper temporary traffic control in accordance with the sections of the Illinois Manual on Uniform Traffic Control Devices concerning temporary traffic control and incident management. The officer should also receive training in safe practices for accomplishing these tasks near traffic. This Section does not apply to highways under the jurisdiction of the Illinois State Toll Highway Authority. As used in this Section, "highway" has the meaning set forth in Section 1-126 of this Code.
625 ILCS 5/11-213