Why is it forbidden to use these types of brake ?

In my understanding, it’s because those types of brakes are incredibly noisy. They are typically only on semi-trucks (or other large vehicles) that need a lot of stopping power. Often the only place they are prohibited is in towns and residential areas, where the sound would be particularly disturbing.

Again, this is just off the top of my head, I could be wrong.

They are much too loud! They can be used on a highway, but not in residential area.

Jake brakes are f***ing loud!

Here is a more in-depth look at the Jake brake and why they are outlawed in certain municipalities.

It’s all about the noise.

Also read this and report any signs that specifically say “Jake Brake.”

Signs will also say “No engine braking”.

Physical brakes, like those on the wheels of your car, use friction to stop your vehicle. Friction builds up as heat. If too much heat is built up, those brakes can cease functioning properly. And you can’t stop then.

On a tractor trailer, they’re subject to the same laws of physics. The problem hits them most directly on mountain roads with really long down hills. If the trucker rides his physical brakes the entire time, they could overheat, cease functioning and he’d be in real jeopardy.

And so enters the engine/jake/compression brake. It simply uses the compression of the truck’s engine to slow the vehicle. It’s not using friction on a brake surface. It’s directly slowing the wheels via the transmission. And it’s also very loud. Essentially, it’s unmuffled engine noise vented out.

As a general rule in residential areas around most cities and towns, there’s no need for engine braking as the truck isn’t taxing its physical brake system much at all.

they’re really loud. have you ever heard a tractor trailer go by making that extremely loud fart noise? i believe thats a jake brake.