The term bobtail has a lot of meanings, depending on what industry or field you are talking about. Today, we’re going to find out what bobtail means in relation to trucking and whether it is positive or negative in the profession.

What does bobtail mean in trucking: The term bobtail refers to the absence of a trailer with a semi-truck. The cab is detached from the trailer and usually, a driver is going from one location to another to pick up their load. Drivers need to be extra careful when bobtailing as the load of the cab is not distributed equally, so there is more strain on the front tires. Braking can take a lot longer, especially in slippery weather.

What is bobtailing?

There are two parts to a tractor-trailer, which you can probably realize means the tractor and the trailer. The tractor, or truck part, tows the trailer, which is full of goods and products.

When a trailer is no longer connected to the truck and you just have the truck on its own, this is referred to as bobtailing.

Why does bobtailing occur?

Bobtailing most often occurs if you need to drive your semi-truck to a pickup location. Many owner-operators will store their trucks in special yards and then will need to drive them to a depot where a trailer is attached.

The trailer part is owned by the company, so if you drive a truck on your own, you won’t also have a trailer attached to it when not in use.

Why is it called a bobtail?

The origins of the term bobtailing are a little muddy, but there are a few cute theories.

The first goes back to the song “Jingle Bells,” which includes the line “bells on bobtails ring.” In the song, it refers to a type of sleigh and this was enough of a transportation link to transfer to trucking.

Another theory is that a bobtail refers to a type of cat that has a short stub for a tail. Without a long trailer attached to it, a semi-truck does look a bit like a cat with no tail.

How long is a bobtail?

A bobtail is just the cab part of a semi-truck. This total length will vary because different cabs are different sizes.

For example, you can have some cabs that are extra long if they have a larger sleeping compartment and more storage.

A bobtail is usually 20 feet long. This is measured from the wheelbase or the front wheel axle to the back wheel axle. In comparison, the total length of a semi-trailer with a trailer is between 70 and 80 feet long.

Types of a bobtail truck

Types of a bobtail truck

Small Bobtail Truck

These are small to medium trucks and are unique because their wheel axles are connected to the same chassis. They have a smaller load than full-size semi-trucks.

Running Bobtail Truck

This term relates to smaller semi-trucks that don’t have a trailer.

Straight Propane Truck

Propane is transported in rounded takes that sit atop a semi truck’s trailer. They are different than semi-truck bobtails because they still have their load attached to the back.

Why do truckers dislike bobtailing?

You would think that a semi-truck cab with no trailer attached to it, which is what bobtailing is, would be easier to drive. After all, there is no heavy trailer slowing things down.

However, bobtail driving can be quite dangerous and so truck drivers like to minimize the amount of driving to stay safe.

Bobtailing is dangerous because a semi-truck is designed to carry a trailer. The weight distribution is more even with more weight behind it.

A lot of this has to do with the weight distribution of the truck. More weight now goes on the front wheels instead of the back wheels, because the truck cab is more forward.

The problem is the semi-truck is designed to have more power on the back wheels when towing a trailer. The front wheels are meant to steer but the reverse happens with bobtailing.

While skilled truck drivers will still be able to maneuver a bobtail truck, those with little experience can find it overwhelming. If you add in bad weather such as rain and slippery road surfaces, this is where accidents can happen.

How to prevent accidents while bobtailing

Part of your driving education will cover bobtailing, so you should learn important strategies. Still, it can take months if not years to really become comfortable with the experience.

When braking, always go slowly. Too much force on the brakes can cause the truck to fishtail.

Be sure to leave more room between the cars around you on a highway, especially with the car driving in front of you. This way if you have to brake, you have more time to stop and can do so more slowly.

Is bobtailing the same as deadheading?

There are a lot of trucking terms, so it can be confusing to keep them all straight. Deadheading is when you have a semi-truck that doesn’t have a load on the trailer.

Deadheading happens when you need to transport your trailer to another location but don’t have anything to replace it with. However, the empty trailer will still be attached to the truck.

The biggest difference is that you can see the empty trailer attached to the truck with deadheading. It will look like an empty flatbed truck. With a bobtail, however, it will just be the wheels.

The two terms are further confused because a semi-truck has a lot of wheels attached to the truck. The trailer actually only has back wheel axles, and the front wheel axles are attached to the truck itself. So, you may see a truck with three sets of wheels and think it is towing a trailer when in actual fact, that is just how a semi-truck is designed.


Bobtail trucks are usually just semi-trucks that don’t have a trailer attached to them. Bobtailing can be dangerous because the weight distribution is off, so drivers need to exercise more caution and ensure there is more space around them while driving.