Replaces everything after the enacting clause. Amends the Illinois Vehicle Code. Provides that the use of green oscillating, flashing, or rotating lights, whether lighted or unlighted, is prohibited except on specified vehicles. Provides the conditions that must be satisfied for the lights on certain specified vehicles with green oscillating, flashing, or rotating lights to be lighted. Provides that fire department vehicles of local fire departments and State or federal firefighting vehicles, police vehicles of State, federal, or local authorities, and vehicles designated by local or State authority, while parked at an emergency scene, may use a steady-on illumination or steady-burn, or flashing green beacon or beacons if such steady-on, steady-burn, or flashing beacon is used to indicate an emergency operations command post or incident command location.