What Is Bobtail in Trucking?
Also called: Bobtailing, Bobtail Tractor, Bobtail Insurance
Bobtail means driving a semi tractor with no trailer attached, and it is also the name for a tractor running alone. A bobtail is lighter and shorter than a full rig, so it can brake and handle differently. Bobtail insurance is a policy for liability while you drive the tractor without a trailer, and it usually does not cover you when you are hauling freight.
Last reviewed September 23, 2026
Key Points
- Bobtail means a semi tractor running without a trailer. A tractor with a trailer is a combination
- The power unit's GCWR is not used to define a commercial motor vehicle when it is not towing (49 CFR 390.5). Its own GVWR decides the CDL group
- A single vehicle with a GVWR of 26,001 pounds or more is in Group B under 49 CFR 383.91. A Group A CDL covers it too. Ask your state before you bobtail on a lower license
- A bobtail has less weight on its drive axles, which can change braking and handling. Leave more following distance
- Bobtail insurance usually covers liability when you drive the tractor without a trailer and are not hauling for a carrier. Your policy sets the exact rules
- A bobtail is still a heavy truck. Weigh station rules are set by each state, so follow the signs
What does bobtail mean in trucking?
Bobtail means a semi tractor driving without a trailer. Drivers say they are bobtailing when they run the tractor alone, such as after a drop, on the way to pick up a trailer, or on a trip to the shop. A bobtail is lighter than a full rig. It is also shorter, so it takes a different line in a turn and has a different feel on the road.
Do you need a CDL to drive a bobtail?
Yes, for a typical tractor. Federal rules put a CDL group on the rating of the vehicle. A power unit's GCWR is not used when it is not towing (49 CFR 390.5), so a bobtail is a single vehicle. A single vehicle with a GVWR of 26,001 pounds or more is in Group B (49 CFR 383.91). Most Class 8 tractors are rated well above that. A Group A CDL covers Group B vehicles too. States issue the license and may set their own rules, so check with your state before you drive a bobtail on a Class B.
Does bobtail insurance cover you?
Bobtail insurance covers liability if you hit something while driving the tractor without a trailer, and usually only when you are not under dispatch. When you are hauling a load for a carrier, the carrier's insurance is the policy that applies. Policies and leases differ, and some have gaps. Some carriers require owner-operators to carry bobtail or non-trucking liability coverage. Read your lease and your policy, and ask your agent what is covered and when.
Is a bobtail harder to drive than a full rig?
It can be. With no trailer, there is less weight on the drive axles, so the tires have less grip. Hard braking can lock the wheels, and the tractor can feel skittish on wet or icy roads. Many drivers leave extra following distance, brake earlier and take turns slowly when bobtailing. A bobtail also sits shorter, which helps in a tight yard, but a tractor with a long wheelbase still needs room.
Does a bobtail have to stop at weigh stations?
It depends on the state and the sign. Each state sets its own scale rules, and many apply to commercial vehicles above a set weight. A bobtail tractor is a heavy truck. Follow the signs for open scales, and check the state's rule if you are not sure. Our scale guide explains what scales check.
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Frequently Asked Questions
What is a bobtail truck?+
A bobtail is a semi tractor driving without a trailer. Drivers also call it bobtailing. It is lighter and shorter than a full rig, so it brakes and handles differently.
Can you bobtail a semi without a CDL?+
In most cases no. A tractor rated at 26,001 pounds GVWR or more needs a CDL, even with no trailer (49 CFR 383.91). Most Class 8 tractors are rated well above that. Check your state for any other rules.
Can you bobtail with a Class B?+
Under the federal groups, a bobtail tractor is a single vehicle, and a single vehicle with a GVWR of 26,001 pounds or more is in Group B. A Group A CDL also covers it. States issue the license and may have their own rules, so ask your state before you do it.
Does bobtail insurance cover you?+
Bobtail insurance covers liability when you drive the tractor without a trailer, usually when you are not under dispatch. When you haul a load for a carrier, the carrier's policy applies. Read your lease and policy, and ask your agent what is covered.
Does a bobtail truck have to stop at scales?+
It depends on the state and the sign. Many states apply scale rules to commercial vehicles above a set weight, and a bobtail tractor is a heavy truck. Follow the posted signs and check the state's rule.
Is bobtailing dangerous?+
It can be harder to control. With no trailer there is less weight on the drive axles, so the wheels can lock under hard braking and the tractor can slide on wet or icy roads. Leave extra space, brake earlier and slow down in turns.
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This is industry terminology and typical practice. It is not legal or tax advice. Rates, fees, and rules mentioned are general ranges. Confirm the details on your rate confirmation, carrier agreement, or a current official source.