What's the safest way to brake when I'm towing?

A tractor trailer crash
Trailers can be tricky to maneuver, so caution and careful braking are critical.
Sandra Mu/Getty Images

The majority of the driving population -- those whose vehicles are having a good day, anyway -- takes a lot of things for granted. Their vehicles speed up, slow down, back up and turn when they require them to and with relative ease. Barring a slick road or other natural interruption, everything usually goes as planned. But if you add a couple thousand pounds onto the back in an independent vehicle, everything gets a little more complicated.

This additional weight makes itself known during almost every stage of a trip, but perhaps none so much as when you need to hit the brakes. One of the reasons braking while towing is such a challenge stems from the notion of inertia -- because nobody likes change, right? Inertia means objects feel the same way; if something is resting, it tends to stay at rest. If something is moving, it tends to stay moving unless another force interferes with its motion. Braking a trailer, especially if it doesn't have any brakes of its own, is messing with its inertia in a big way. The tow vehicle might be slowing down, but the trailer is still raring to go, and this can cause it to swing dangerously. Also, any cargo that's not strapped down will probably go flying.


Whether you've never towed anything before or you have but you're a little unsure about a new load, an important consideration to remember is that it never hurts to practice. Take a spin around some back roads where traffic is light and do a little experimenting. As you drive along, get a feel for how long it takes you to stop and how your trailer responds to braking at different speeds.

Another thing to note is that the advice of someone with experience in towing can be invaluable for a beginner or even a veteran who needs a refresher. Plus, there's always the chance he or she might have some gripping tales of emergency braking nightmares that'll scare you into taking it slow the first time.

Let's level the playing field with the forces of inertia a bit and learn about the types of brakes your trailer can be equipped with on the next page.


Gimme a Brake!

Trailer brakes are often activated in tandem with the tow vehicle's brakes.
Phil Banko/Photographer's Choice/Getty Images

Trailers can have a couple of different kinds of brakes, especially for heavier payloads, and these brakes are often required by law. When your goal is to achieve the safest possible braking experience, trailer brakes are definitely recommended -- the more the merrier.

Trailer brakes generally fall into two categories:


  • Electric brakes are basically the same as the brakes you'll find in the tow vehicle. They're usually disc brakes or drum brakes -- the key is that they're electrically activated by the driver of the tow vehicle. Wiring from the tow vehicle's electrical system runs through a controller located between the two vehicles and signals the brakes of the trailer as needed. The driver can manually activate the electric brakes -- say if the trailer begins to sway -- or the brakes can be set to function automatically, typically operating in one of two ways:
  • In one setup, the brakes are set to react to the driver's brake pedal with a slight delay, and with a predetermined level of stopping action. That level is set according to the weight of the trailer. These systems are often more user-friendly and are usually cheaper.
  • In another system, the brakes of the trailer automatically mimic the actions of the brakes in the tow vehicle. This makes for a smoother brake and can be very helpful when you need to make an emergency stop.
  • Hydraulic surge brakes are not specifically driver-controlled; they kick into effect automatically whenever the driver slows the tow vehicle. This happens because of inertia, with the surge brakes working hydraulically through the hitch. As the tow vehicle slows, the trailer presses harder against the hitch and compresses the braking actuator. The more the tow vehicle decelerates, the more stopping power the surge brakes generate.

On the next page, we'll go over a few practices that can greatly improve your braking and increase the safety of the towing experience.


And Then All Hell Brakes Loose

Unless you're trying to get to Oz, pack carefully and avoid slamming on the brakes, otherwise your hitch might dive.
Steve Satushek/Photographer's Choice/Getty Images

By keeping a few things in mind, braking with a trailer doesn't have to be traumatic at all. After you've had a little practice on some quiet streets getting accustomed to braking with the trailer, you're ready for the big day.

You'll definitely want to pack carefully so no surprises pop up along the way. For example, if you have too much weight on the hitch or a load with a high center of gravity, slamming on the brakes can send the front end of your trailer into dive, taking your tow vehicle's rear axle down with it. Unless you're looking to go somewhere over the rainbow, this is a bad thing. So definitely take the time to make certain everything's stowed carefully. You can get more tips on how to do this by reading How to Load and Unload Towed Vehicles.


You're finally underway, but nobody else on the road seems to understand how eager you are to get to the lake! It's a pity, but it's just something you'll have to accept. Some of the worst things you can do while driving a trailer are drive too fast or follow too closely, let alone ride someone's bumper. Stopping with a trailer takes roughly double the time it takes to stop a solo vehicle, and it can take even longer depending on the weight of the load. Plus, with more speed you get more sway (swing from side to side). If you do experience sway, taking your foot off the gas and gently applying the trailer brakes can help ease this movement; slamming on the brakes of the tow vehicle can be a disaster. Always keep your driving slow and controlled, with ample distance between you and anyone you're driving behind.

If lesson one was all about space and speed, lesson two focuses on anticipation. Keep an eye out for anything that might mean you need to brake ahead. Did somebody just pull out of a parking lot in front of you? Are people merging onto the highway? Is there a traffic jam up ahead? You always want to have a heads-up for a potential need to brake.

Another thing you want to keep in mind is the use of engine braking, also commonly called compression braking. Engine braking (using lower gears to slow a vehicle instead of the brakes) not only helps your brakes last longer, it also spares them from overheating, something that happens much more quickly when you add the weight of a trailer to a vehicle. If you're doing a lot of braking, say in order to go down a hill, you'll probably want to practice engine braking along the way. You can use it at other points in your drive as well. Your brakes will last longer and you'll know they'll be there when you need them. But over time, it will increase the wear and tear on other parts of your vehicle, as well as cost you more in fuel.

One other thing to note in relation to the brakes -- you don't ever want to keep your foot resting on the brake pedal when you aren't trying to slow down. The smallest pressure will cause the brakes to operate at a low level and wear them out that much faster.

So basically, the trick to safe braking when you're towing is to get a feel for it ahead of time, use a redundant brake system in case something unexpected goes wrong, pack your cargo carefully, don't speed, leave yourself plenty of space to brake while anticipating the need to brake ahead of time, and last but not least, take it easy on your brakes -- they'll make or break your trip!

For lots more links about towing, braking and the laws of motion, stop on the links on the next page.


Lots More Information

Related HowStuffWorks Articles

More Great Links


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