What does bobtail mean in trucking?

Driving a tractor with no trailer attached. It happens between loads — after dropping a trailer, on the way to the next one, or going home at the end of a run.

Is bobtailing on-duty time?

When it is to pick up another load, yes: FMCSA's personal conveyance guidance excludes bobtailing to retrieve a load. A short trip to rest after being relieved of all work can be personal conveyance.

What is bobtail insurance?

Cover for a leased tractor when it is not working under the carrier's dispatch. US leasing rules require the lease between carrier and owner-operator to say who provides it.

Term

Bobtail

Bobtail is a tractor driven without a trailer — after dropping one, on the way to collect the next, or heading home. A bobtail handles worse than a loaded rig: US commercial driver training warns it takes longer to stop. Driving bobtail to pick up another load is on-duty driving, not personal time.

Also called bobtailing, bobtail truck, bobtail insurance, tractor without trailerApplies in USUpdated 13 October 2026

What bobtail means

The commercial driver's licence manual that US states teach from, written by AAMVA, describes bobtail tractors simply as tractors without semitrailers. The word covers any trip in that state: running to a yard to hook a loaded trailer, leaving a trailer at a drop lot, or driving home after the last delivery of the day.

Why it handles differently

With no trailer over the drive axles, a tractor has little weight on the wheels doing the braking. The manual is blunt about the result: tests have shown bobtails can be very hard to stop smoothly, and they take longer to stop than a tractor-semitrailer loaded to maximum gross weight. Drivers are taught to leave more room ahead and brake earlier.

Worked example: on duty or personal conveyance

Trip	How it counts	Why
After delivering and being relieved of duty, driving bobtail 8 miles to a motel	Personal conveyance, off duty	Allowed for personal reasons, even if the truck is laden
Driving bobtail 40 miles to collect the next loaded trailer	On-duty driving	The guidance excludes bobtailing to retrieve another load
Pulling an empty trailer back to the yard to be loaded	On-duty driving	Excluded in the same way

FMCSA's personal conveyance guidance (2018). On-duty driving counts toward the 11 hours a driver may drive after 10 hours off

Who insures it

That depends on the lease. When an owner-operator leases a tractor to a carrier, US rules require the lease to say who provides other insurance for the leased equipment, naming "bobtail insurance" as an example (49 CFR 376.12(j)). The cover matters for exactly the trips the carrier is not dispatching.

The mistake people make

Logging a bobtail run toward the next pickup as personal conveyance. FMCSA's guidance lists bobtailing to retrieve another load as a business purpose, so those miles belong in the driving log and count against the 11 hours.

FAQ

Bobtail: common questions

What does bobtail mean in trucking?: Driving a tractor with no trailer attached. It happens between loads — after dropping a trailer, on the way to the next one, or going home at the end of a run.
Is bobtailing on-duty time?: When it is to pick up another load, yes: FMCSA's personal conveyance guidance excludes bobtailing to retrieve a load. A short trip to rest after being relieved of all work can be personal conveyance.
What is bobtail insurance?: Cover for a leased tractor when it is not working under the carrier's dispatch. US leasing rules require the lease between carrier and owner-operator to say who provides it.