625 ILCS 5/11-203: Obedience to police officers.

No person shall wilfully fail or refuse to comply with any lawful order or direction of any police officer, fireman, person authorized by a local authority to direct traffic, or school crossing guard invested by law with authority to direct, control, or regulate traffic. Any person convicted of violating this Section is guilty of a petty offense and shall be subject to a mandatory fine of $150.