Signs that read “Trucks Please No Jake Brake” or “No Jake Brakes Within City Limits” are common near residential neighborhoods along popular trucking routes, especially preceding a traffic signal. You may have seen one and wondered what it meant. Not being familiar with big rig terminology, many people don’t know what this means or how it affects them.
What is a Jake brake? “Jake Brake” refers to compression release engine brakes. A feature on large diesel-powered vehicles like semi-trailers, it works by releasing the compressed air in the engine via the exhaust valves to quickly reduce speed, resulting in a loud noise.
In hilly areas and routes with traffic signals on high-speed roads, you’ve likely heard plenty of Jake braking, even if you didn’t know what to call it before. Let’s delve into where the term comes from, why eighteen-wheelers need compression release engine brakes, whether or not Jake braking is legal, why we put up signs against them, and if there are any risks associated with using them.
Where Does the Term “Jake Brake” Come From?
The name comes from the first iteration of the compression release engine brake, which was developed by Jacobs Vehicle Systems. It was initially called the Jacobs Engine Brake Retarder. So, the first version’s name was shortened and referred to as the Jacob Brake. The nickname further developed into the Jake brake.
It was invented in 1957 by Clessie Lyle Cummins as a way to improve semi
highway safety. The idea was to create a braking system that would reduce
overheating and fires due to large, heavy vehicles descending on extreme grade
downhill stretches of road.
Why Do Trucks Have Jake Brakes?
Semi tractor-trailers have a lot of wheels, which means a lot of brake system parts. They also carry great loads of weight. So, all of those brakes have to slow a fast-moving, heavy rig which means an awful lot of friction.
Imagine the wear on the brakes of an eighteen-wheeler heading down a mountain, trying to maintain a safe and controlled speed. Now, imagine if, instead of having to apply a break that used friction to slow their vehicle, all they needed to do was lift their foot off the gas for the engine slow itself down.
That’s what the compression release engine brake is designed to do.
When the driver removes their foot from the gas, with the Jake brake engaged, compressed air builds with the piston at the top of the cylinder. The open exhaust vent means that pressure prevents the piston from powering the down-stroke of the crankshaft. This means that the engine itself creates drag on the wheels to slow the rig down.
So, by slowing the vehicle down without applying a brake, the temperature on the brakes stays low, and the brake pads stay cushioned for another day. It also reduces the amount of time it takes to bring the truck to the desired lower speed (or a full stop). Unfortunately, it’s really loud and obnoxious for anyone around to hear it.
Are Jake Brakes Illegal?
Specifically, in the United States, Canada, and Australia, communities have taken to posting signs in areas where residents are not pleased with the annoyingly loud exhaust noise associated with Jake braking.
However, while there are signs up against Jake braking (or engine braking) in certain areas, it’s definitely not illegal everywhere. It is up to cities to work with the state government to assess their power over creating laws against it.
For example, in 2004, the state of New York determined that “villages” were not in the ownership of the roads (that were state-owned), and therefore couldn’t enact laws against engine braking.
However, places like Chesterfield, Missouri (2016), have been allowed to create laws banning Jake braking, punishable by a $500 fine and up to 90 days in jail.
The best way for a trucker to stay out of trouble is to keep an eye out for signage. It’s important to respect the local community’s wishes.
If there is a particular stretch where the laws seem to hinder to semi driving safety, write to the local community’s council board with the argument. While it’s vital to make sure that the roads are safe and everyone’s voice is heard, it’s also important for a trucker to avoid penalties.
What Good Are No-Jake-Brake Signs?
Some regions have noise by-laws that restrict the use of Jake brakes. This is why you’re likely to see signs near a particular hill or traffic signal. If a local government has determined there is a need to rein in noise pollution, be it for the benefit of the community or animal habitat, they will put up a sign.
This is much to the annoyance of many truckers who’ve reported signs on roads where the speed limit drops from 55mph to 30mph with no warning, and then suddenly, there is a “Please No Jake Brakes” sign. In their collective opinion, using the standard brakes is less safe to slow down their very large and heavy haulers.
This frustration has, however, been addressed with a number of local governments. While residents may fight for signs to go up so that they are not awakened in the middle of the night by the loud horn-like blasts of trucks trying to slow down to residential speed quickly, truckers can usually sway a board with a safety argument.
Should you find yourself in a deciding situation, remember, both sides have a valuable opinion in the argument. It’s worth having the discussion to figure out a solution that will create a compromise. This may be a No Jake Brakes sign, or it might be a speed limit change warning sign.
Signage Examples
Because “Jake break” is a nickname for the compression release engine brake, and since that is a long name, the wording on the signs varies quite a lot. Here are some examples:
- No Jake Brakes
- Compression Braking Prohibited
- No Engine Breaks
- Brake Retarders Restricted
- Unmuffled Compression Brakes Prohibited
There are even variations off of these examples. The above listings are meant to show how many different names there are.
Are There Any Risks to Using a Jake Brake?
Jake brakes are safe enough to use in dry conditions when the engine is at operating temperature with the appropriate level of oil. However, there are conditions that are not optimal for using them.
The most notable risky situation for jake-braking is on a slippery road. Whether wet or icy, if a trucker applies the compression release engine brake without having their rig 100% straight, they risk jackknifing. However, for the truck driver, this about the only real risk to using a jake brake.
Where most people see the risk in Jake brakes is when rude truckers use the loud noise to scare others. Reports of Jake braking to startle bicyclists, pedestrians and even small children are widespread and have resulted in the heavily unfavorable opinion that most of the public has of the safety feature.
Wrapping It Up
They’re loud and frankly kind of annoying, especially if you live near a highway, but in hilly areas with speed variations, compression release engine brakes, or “jake brakes” might be the best way for a trucker to slow their rig down without extra wear on their brakes. Unless there is a sign against it, they are within their rights to do it.