What Is Bobtailing?
Bobtailing means operating a tractor (cab) without a trailer attached. The term comes from the short, "bobbed" appearance of a truck driving without its back half.
Common bobtailing scenarios include driving from your home to a shipper to pick up a trailer, returning after dropping a trailer at a receiver, or repositioning between loads.
According to the FMCSA, bobtailing is one of the higher-risk driving configurations due to the weight distribution problems it creates.
What Is Deadheading?
Deadheading means driving with an empty trailer attached to the tractor. The trailer is connected but carries no cargo.
Common deadheading scenarios include repositioning an empty trailer from a receiver to a shipper, returning a trailer to a terminal, or moving to a pickup location where the load requires a specific trailer type.
While deadheading generates no revenue (hence "dead" miles), it maintains better vehicle stability than bobtailing because the trailer adds weight to the rear axles.
Key Differences at a Glance
| Factor | Bobtailing | Deadheading |
|---|---|---|
| Trailer | No trailer attached | Empty trailer attached |
| Revenue | None | None (usually) |
| Safety Risk | Higher | Moderate |
| Braking | Significantly impaired | Near normal |
| Stability | Poor — light rear end | Good — balanced weight |
| Insurance | Bobtail or NTL policy | Primary liability |
Deadheading (empty trailer)
- +Near-normal braking — the empty trailer keeps weight on the drive and trailer axles
- +All 18 brakes are available for stopping power
- +Better stability and cornering than running bobtail
- +Typically covered by your carrier's primary liability when done under dispatch
Bobtailing (no trailer)
- −Drive axle is nearly unweighted, so the rear brakes lose most of their traction
- −Stopping distances increase roughly 20-40% versus a loaded truck
- −Higher risk of skidding, jackknifing, and wind-related instability
- −Off-dispatch bobtailing usually requires separate bobtail or NTL coverage
Why Bobtailing Is More Dangerous
A semi-truck's braking system is engineered to stop a fully loaded vehicle weighing up to 80,000 pounds. When you remove the trailer, you eliminate roughly 60-70% of the vehicle's intended weight — but the brake system was designed for that full weight.
Key Safety Fact
The FMCSA reports that bobtailing accidents, while less frequent than loaded truck accidents, often involve loss of vehicle control. The physics are simple: less weight on the drive axle means less tire grip, longer stopping distances, and reduced stability in turns.
Bobtailing Risks Include:
- Stopping distances increase 20-40% compared to a loaded truck
- Rear wheels can lock up and cause skidding in wet conditions
- Wind gusts affect the high-profile cab with no counterbalancing trailer weight
- Cornering stability is reduced — higher rollover risk in turns
- Loss of rear-axle braking power since brakes were designed for trailer weight
Braking Physics Explained
A typical semi-truck has 10 brakes — 2 on the steer axle and 8 on the drive axles. When a trailer is attached, it adds another 8 brakes on the trailer axles for a total of 18 brakes working together.
When bobtailing, you only have 10 brakes, but more importantly, the drive axle brakes have very little weight pressing the tires to the road. Brake effectiveness depends on friction, and friction depends on weight. Less weight means less friction means longer stopping distances.
With deadheading (empty trailer), you have all 18 brakes and the trailer adds enough weight to maintain reasonable traction on the drive and trailer axles. The braking performance is closer to normal, though not as effective as a fully loaded truck.
Pro Tip
Insurance Coverage Differences
The insurance that covers you while bobtailing is different from what covers you while deadheading. Understanding which policy applies in each scenario prevents dangerous coverage gaps.
Bobtailing Coverage
When you are bobtailing and NOT under dispatch, you need either a bobtail insurance policy or non-trucking liability (NTL).
Your motor carrier's primary liability typically does NOT cover you when bobtailing off-dispatch. As required by FMCSA insurance regulations, you need separate coverage.
Deadheading Coverage
When deadheading under dispatch (repositioning for a load), your motor carrier's primary liability policy typically covers you since you are performing a business activity.
If you are deadheading for personal reasons (not under dispatch), the coverage depends on whether the activity qualifies under your NTL or bobtail policy terms.
Important Distinction
Safety Tips for Each Scenario
Bobtailing Safety Tips
- Increase following distance by 50% — you need more room to stop
- Reduce speed in rain, snow, or ice — rear tires have minimal grip
- Avoid sudden lane changes — the cab is less stable without a trailer
- Brake gently and early — hard braking can cause skidding
- Take turns wider and slower than you would with a trailer
- Be extra cautious on downhill grades — engine braking is less effective
Deadheading Safety Tips
- Secure all trailer doors and equipment — loose items can cause problems
- Check tire pressure on the empty trailer before heading out
- Be aware that empty trailers are more susceptible to wind gusts
- Reduce speed in crosswind conditions — the empty trailer acts as a sail
- Monitor your cost per mile — deadhead miles reduce profitability
How Dispatchers Minimize Both
A good dispatcher reduces both bobtailing and deadheading by finding efficient backhaul loads and minimizing deadhead miles.
At O Trucking, we plan routes to keep our carriers loaded as much as possible, reducing the time spent bobtailing or running empty. Every deadhead mile costs you money, and every bobtailing mile adds unnecessary safety risk.
Our dispatchers use load boards, broker relationships, and route optimization to find loads that minimize repositioning time. When bobtailing or deadheading is unavoidable, we factor that into the rate negotiation to protect your cost per mile.
Tracking Your Deadhead Percentage
The single most useful metric for measuring empty-mile waste is your deadhead percentage — the share of your total miles that are unpaid empty miles. It is a simple ratio you can calculate yourself:
Deadhead % = (Empty Miles ÷ Total Miles) × 100
Example: a driver who runs 400 empty miles out of 2,400 total miles in a week has a deadhead percentage of (400 ÷ 2,400) × 100 = roughly 17%.
Lower is better — every percentage point you shave off is fuel and drive time spent earning instead of running empty. Track it weekly so you can spot lanes and brokers that consistently leave you repositioning. Use our deadhead miles calculator to run the numbers, and pair it with smart backhaul strategies to keep the figure trending down.
How Our Team Keeps You Safe and Covered
Route Planning to Minimize Risk
We plan loads to reduce bobtailing and deadheading, keeping you loaded and earning revenue while staying safer on the road.
Insurance Guidance
We help carriers understand their insurance coverage gaps and ensure they have proper bobtail or NTL coverage for off-dispatch driving.
Backhaul Optimization
Our network of brokers and shippers helps us find return loads so you spend less time running empty or bobtailing.
Frequently Asked Questions
Ahmad Qazi
Founder & CEO, O Trucking LLC
Written by Ahmad Qazi, founder of O Trucking LLC, drawing on 9+ years dispatching for owner-operators. Learn more about us.
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