(A) The driver of a commercial vehicle, as defined in § 70.001 of this code, is prohibited from operating or actuating any engine braking system that emits excessive noise. Signs shall be posted indicating the prohibition.
(B) The sign shall state, “EXCESSIVE ENGINE BRAKING NOISE PROHIBITED”. The State Department of Transportation shall adopt rules providing for the erection and placement of these signs.
(C) This section does not apply to the use of an engine braking system that has an adequate sound muffling system in proper working order that prevents excessive noise.
(D) It is a defense to this section that the driver used an engine braking system that emits excessive noise in an emergency to avoid a collision with a person or another vehicle on the highway.
(E) A violation of this section is an equipment violation punishable as provided in § 70.999.
(625 ILCS 5/12-602.1) Penalty, see § 70.999