top of page

Bring The Noise, Or Don’t

Several years back, a stereo company produced a commercial to advertise the audible power of their stereo systems.  It featured what appeared to be two business men dressed in black suits driving a luxury vehicle.  The driver put a CD in the stereo and ‘Another One Bites the Dust’ by Queen came on.  The commercial goes on to show the superior sounds the speakers are producing.  The camera eventually pans out so the audience can see the men are driving the lead hearse in a funeral procession!  As entertaining as the commercial was, it turned out that the excessive noise was not a good idea.  Sometimes in the trucking industry, excessive noise can also carry consequences.

Last month the ITEA published an article about engine braking.  Part of that article covered how the ‘excessive noise’ from engine braking can get truck drivers into trouble.  The article this week will mention how Illinois feels about other excessive noises coming from vehicles upon their highways.

Exhausts Every internal combustion engine produces a byproduct generically referred to as exhaust.  In a petrol engine, the exhaust coming out of the pipes is nothing more than nitrogen, water vapor, and carbon dioxide.  While carbon dioxide is a greenhouse gas, none of these compounds are toxic.  In a diesel engine, the exhaust is a source of atmospheric soot, which is a component of the air pollution implicated in human cancer.  While these facts are important, they are for another discussion.

As exhaust gases travel through the exhaust pipes, they begin to expand and create noise.  This process is inevitable, as all internal combustion engines in commercial vehicles need to expel their exhaust gases.  It is clearly spelled out in the Federal Motor Carrier Safety Regulations (FMCSR) under 393.83.  What’s not spelled out is the noise the exhaust is allowed to make.  The FMCSR does clearly explain how much noise a commercial vehicle can make, but only when measured from inside the vehicle.  However, Illinois says something different, and possibly more confusing.  Illinois law reads:

(625 ILCS 5/12-602) Mufflers, prevention of noise. “Every motor vehicle driven or operated upon the highways of this State shall at all times be equipped with an adequate muffler or exhaust system in constant operation and properly maintained to prevent any excessive or unusual noise. No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all the requirements of this Section.”

According to the last sentence of the law, it is illegal to modify the exhaust of any commercial vehicle that will cause an increase in noise.

How many trucks are driving though Illinois right now with aftermarket custom chromed out six inch pipes?  Thousands…  Does this mean that thousands of trucks in Illinois are breaking the law?  The letter of the law says “yes”.  The spirit of the law will hopefully mean something different to those charged with enforcing it.

Horns Every commercial motor vehicle needs a horn.  This is common sense and is clearly spelled out in the FMCSR under section 393.81.  This section is very vague and simply states that every truck and truck tractor shall be equipped with a horn.  To no surprise,

Illinois law is more complicated on the matter.  Illinois law reads:

(625 ILCS 5/12-601) Horns and warning devices. “Every motor vehicle when operated upon a highway shall be equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than 200 feet, but no horn or other warning device shall emit an unreasonable loud or harsh sound or a whistle. The driver of a motor vehicle shall when reasonably necessary to insure safe operation give audible warning with his horn but shall not otherwise use such horn when upon a highway.”

Perhaps easy reading, but Illinois yet again fails to define what an unreasonable loud or harsh sound is.  Is it a loud electronic horn?  It is an air horn?  This is another situation where we all hope that common sense and good discretion comes to the rescue.

Truckers – What does your exhaust sound like?  Are you able to control the noise it emits when engine braking or downshifting?  Do your surroundings dictate you should keep the noise to a minimum? Is your need to use the horn for the safety and well being of the motoring public, or to remind a driver to get off the phone and pay attention?  Should you go electric or air?

Police Officers – Remember, for truck drivers, especially owner operators, their truck is not only their office, but their home as well.  Most drivers take pride in their mobile offices and customize them as they see fit.  That may often include smoke stacks which stand tall and scream American pride.  Ask yourself if an electric horn is adequate to let the motoring public know that there is a problem with an eighty-thousand pound mobile office barreling down the highway.

62 views0 comments

Recent Posts

See All


bottom of page