Illinois Engine & Jake Brake Rules
No statewide ban on the engine brake itself in Illinois. Two statutes matter. The muffler law (625 ILCS 5/12-602) requires an adequate muffler, no cutout or bypass. A second law (625 ILCS 5/12-602.1) lets counties, cities, and IDOT post 'EXCESSIVE ENGINE BRAKING NOISE PROHIBITED' signs, often near weigh stations by homes, with a $75 fine. It exempts a truck with proper muffling and excuses emergency use. Obey the sign, run the engine brake on grades with none.
How Illinois handles engine braking
No statewide ban on the engine brake itself in Illinois. Two statutes matter. The muffler law (625 ILCS 5/12-602) requires an adequate muffler, no cutout or bypass. A second law (625 ILCS 5/12-602.1) lets counties, cities, and IDOT post 'EXCESSIVE ENGINE BRAKING NOISE PROHIBITED' signs, often near weigh stations by homes, with a $75 fine. It exempts a truck with proper muffling and excuses emergency use. Obey the sign, run the engine brake on grades with none.
What to watch for
- Ban scope: Local / posted
- Where posted & enforced: Local, plus a state sign law. Under 625 ILCS 5/12-602.1, counties, cities, and IDOT may post 'EXCESSIVE ENGINE BRAKING NOISE PROHIBITED' signs, especially near weigh stations next to residential areas. Towns also post their own 'no engine brake' signs on truck routes. Enforcement concentrates around those weigh-station and residential zones. Flat state, so it is about noise, not grades.
- Muffler / noise law: Yes, the real legal hook
- Fine: $75 under the state engine-braking-noise sign law (625 ILCS 5/12-602.1). Local ordinance fines may differ.
Illinois Engine Brake FAQ
Are engine brakes banned in Illinois?
Where are the "NO ENGINE BRAKE" signs in Illinois?
What is the fine for using an engine brake where it is banned in Illinois?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://codes.findlaw.com/il/chapter-625-vehicles/il-st-sect-625-5-12-602-1/. See our Terms & Disclaimer.
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