Underglow in Illinois
Underglow may not be used on public roads in Illinois. Unauthorized oscillating, rotating, or flashing lights are a Class A misdemeanor even when unlit, and only limited amber or white cowl and courtesy lamps are permitted, so underglow use on public roads is treated as illegal.
Verified against primary sources · August 2026
What the law says
Unauthorized oscillating, rotating, or flashing lights are a Class A misdemeanor even when unlit, and only limited amber or white cowl and courtesy lamps are permitted, so underglow use on public roads is treated as illegal. Mounting the lighting is not itself an offense; using it on a public road is. Private property is where it can be run.
Specific Limits
- Allowed
- parked on private property
- While driving
- prohibited
Exceptions & Exemptions
Underglow lights must not be red or blue, must not flash or strobe, and generally must not be visible while driving on public roads. White and amber lights may be more permissible but should not be distracting to other drivers.
Frequently Asked Questions
Are underglow legal in Illinois?
What are the exact underglow limits in Illinois?
Are there exceptions for underglow in Illinois?
Street-legal underglow picks
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