430 ILCS 70/3
It is unlawful for any person, group or organization to conduct or participate in any march, assembly, meeting, parade, or gathering on roadways in more than one specific area of or location in, any municipality or the unincorporated area of a county, on any given day, unless it is acting under authority of a duly issued municipal or county parade or demonstration permit if local ordinance or regulation requires a permit, or, if not, with permission of the principal law enforcement officer for the area. Only the person, group, or organization responsible for organizing the march, assembly, meeting, parade, or gathering is required to obtain a permit or the permission of the principal law enforcement officer, which shall be sufficient to encompass all participants. If a march, assembly, meeting, parade, or gathering on roadways involves the act of crossing or traversing over or upon active railroad tracks, the municipal or county authority or principal law enforcement officer, as part of its permit or permission process, may prohibit any portion of the route that involves the act of crossing or traversing over or upon active railroad tracks.
430 ILCS 70/3