By Bob Paterson Decorative underglow lighting is generally not legal for use while driving on public highways in Illinois. Illinois tightly controls the types of lights that may be displayed on motor vehicles and prohibits lighting or combinations of lighting that are not specifically authorized by the Illinois Vehicle Code. Additional restrictions apply to red, blue, flashing, oscillating, and rotating lights because these colors and lighting patterns are associated with emergency and authorized vehicles.
What Does Illinois Law Say About Underglow?
Vehicle lighting in Illinois is regulated primarily under Chapter 12 of the Illinois Vehicle Code, 625 ILCS 5.
The most important provision is Section 12-212, which contains special restrictions on vehicle lamps.
Illinois law states that, unless otherwise expressly authorized by the Vehicle Code, all other lighting or combinations of lighting on a vehicle are prohibited.
Because decorative neon or LED underbody lighting is not generally listed among the lighting equipment authorized for ordinary passenger vehicles, using underglow while driving on an Illinois highway can violate the state’s vehicle-equipment rules.
The law applies regardless of whether the lighting was installed by the vehicle owner or by an aftermarket customization business.
Are All Underglow Colors Illegal While Driving?
Illinois does not provide ordinary drivers with a general list of approved decorative underglow colors.
The Vehicle Code does specifically authorize certain types of lighting for defined purposes. For example, ordinary vehicles may have specified white or amber headlamps and certain amber or white side or running-board courtesy lamps.
However, these limited authorizations should not be interpreted as permission to install full-length amber, white, green, purple, or other decorative LED strips underneath a vehicle and illuminate them while driving.
The broader rule in Section 12-212 prohibits additional lighting that the Vehicle Code has not expressly authorized.
Therefore, simply choosing a color other than red or blue does not necessarily make driving with underglow legal in Illinois.
Is Red Underglow Legal in Illinois?
Red underglow creates additional legal concerns.
Illinois prohibits a vehicle traveling on a highway from displaying a red light that is visible directly from the front, except when specifically permitted by law.
Red lighting is also heavily regulated when it flashes, rotates, or oscillates because those lighting patterns are reserved primarily for law-enforcement, fire, ambulance, and other specially authorized vehicles.
For an ordinary passenger vehicle, red decorative lighting visible toward the front should therefore not be used.
Even steady red underglow that is not visible from the front may still fall under the general prohibition against unauthorized additional vehicle lighting.
Is Blue Underglow Legal in Illinois?
Blue underglow should not be used on an ordinary passenger vehicle.
Illinois law places particularly strict restrictions on blue oscillating, rotating, or flashing lights. Such lights are reserved for specific vehicles and personnel, including certain emergency, fire, rescue, and law-enforcement vehicles.
Illinois also separately prohibits unauthorized possession or control of certain emergency-style lighting equipment, including red and blue LEDs and other equipment that could give the appearance of emergency-vehicle authority.
Even when decorative blue underglow does not flash, an ordinary driver should not assume it is lawful. Illinois’s general rule against unauthorized additional lighting still applies.
Are Flashing Underglow Lights Legal?
Generally no.
Section 12-212 provides that flashing lights are prohibited on motor vehicles unless the Vehicle Code specifically authorizes them.
Examples of permitted flashing lights include turn signals, hazard lights, and particular emergency or service-vehicle lights operating under statutory authority.
Decorative underglow that flashes, pulses, strobes, rotates, or changes rapidly between colors does not become legal simply because it is installed underneath the vehicle.
In fact, a flashing red, blue, white, or green lighting system can create additional problems because Illinois reserves many of these lighting patterns for specific authorized vehicles.
Can You Install Underglow if You Do Not Use It on Public Roads?
The strongest Illinois restrictions concern vehicles being driven or moved on public highways.
A vehicle owner may install decorative equipment for use at car shows, exhibitions, private events, or on private property, but the lighting should not be activated while the vehicle is being operated on an Illinois public highway if it is not authorized by the Vehicle Code.
Installation itself can still become problematic if the equipment falls within Illinois’s restrictions on emergency-style lights, particularly certain oscillating, rotating, or flashing red or blue equipment.
Therefore, a show-car lighting system should be configured so it can remain completely turned off during ordinary public-road operation.
Private property owners and event organizers may also establish their own rules.
Are Running-Board or Courtesy Lights Legal?
Illinois does authorize some limited additional lighting.
Under 625 ILCS 5/12-209, a motor vehicle may have no more than two side cowl or fender lamps that emit white or amber light without glare.
A vehicle may also have one running-board courtesy lamp on each side, provided the lamp emits white or amber light without glare.
This is much narrower than general decorative underglow.
A properly designed courtesy lamp used for illumination when entering or leaving a vehicle should therefore not automatically be confused with a continuous LED system illuminating the entire underside of the car.
Can Underglow Be Used While the Vehicle Is Parked?
Using decorative underglow on private property or at a lawful car show presents a different situation from driving with it illuminated on a public highway.
However, drivers should be careful about activating lighting while parked on or alongside public roads.
Certain flashing, emergency-style, red, blue, or otherwise prohibited lights can remain restricted even when the vehicle is stationary.
Local ordinances may also regulate vehicle lighting, nuisance lighting, parking areas, or car exhibitions.
For practical purposes, decorative underglow is safest when it is used only on private property and switched completely off before entering a public road.
What Are the Penalties for Illegal Underglow?
Driving a vehicle that is equipped or illuminated in violation of Illinois vehicle-lighting requirements can result in a traffic citation.
The precise charge and penalty depend on the type of lighting involved.
A basic unauthorized-lighting violation may be handled as a vehicle-equipment offense. More serious consequences are possible when someone uses prohibited emergency-style lighting.
For example, violations involving unauthorized red, blue, white, or other oscillating, rotating, or flashing emergency lights can constitute a Class A misdemeanor under applicable provisions of Illinois law.
Police may also seize certain unauthorized emergency-lighting devices when the statutory requirements are met.
Frequently Asked Questions
Q1. Can I drive with LED underglow on in Illinois?
Generally no. Illinois prohibits vehicle lighting that is not expressly authorized by the Vehicle Code, and decorative underbody LED lighting is not generally authorized for ordinary passenger vehicles.
Q2. Is white or amber underglow legal in Illinois?
Not automatically. Illinois permits specific white or amber lamps for particular purposes, such as certain running-board courtesy lamps, but that does not create general permission for decorative underbody lighting.
Q3. Can I have underglow installed if I keep it turned off?
A decorative system that remains off while the vehicle is driven on public roads presents a different issue from actually using the lighting. However, emergency-style red or blue flashing equipment can be subject to additional restrictions even when not illuminated.
Q4. Can I use underglow at a car show in Illinois?
Potentially, particularly on private property where public-highway equipment rules are not being applied in the same way. The lights should be switched off before the vehicle is driven on public roads, and any event or local property rules should also be followed.