LCV Doubles Practice Test
Longer combination vehicles — a tractor with two trailers over 80,000 pounds gross. Federal training is required before you may operate one, and only some states permit them at all.
This is federal special training under 49 CFR 380, not a CDL endorsement, and it is only usable in states that permit longer combination vehicles at all.
Do you need this test?
Optional — you only need it if you will actually be driving this way. Every CDL applicant takes the general knowledge test first.
Prerequisite: you need Combination Vehicles, Doubles and Triples before this one.
Practice now
Study the material, not just the questions
Federal training for two or three trailers over 80,000 pounds.
Open the Longer Combination Vehicles moduleThe other tests you'll need
- General Knowledge — 50 questions · 80% to pass
- Air Brakes — 25 questions · 80% to pass
- Combination Vehicles — 20 questions · 80% to pass
- Hazardous Materials — 30 questions · 80% to pass
- Tank Vehicles — 20 questions · 80% to pass
- Doubles and Triples — 20 questions · 80% to pass
- Passenger Transport — 20 questions · 80% to pass
- School Bus — 20 questions · 80% to pass
- LCV Triples — 30 questions · 80% to pass
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Sample LCV Doubles questions
What spacing should an LCV keep from the vehicle ahead?
- A. Whatever the posted signs allow
- B. The same as a passenger car
- C. More than a conventional combination needs
- D. Half a second per trailer
Show answer
C. More than a conventional combination needs — Length and weight both lengthen the stop, so the gap that works for a tractor and one trailer is not enough for an LCV.
Universal rule · checked against 49 CFR Part 380 Appendix F — Appendix F: LCV Required Knowledge and Skills · verified 2026-07-30
How does an LCV behave on a steep uphill grade?
- A. It maintains highway speed easily
- B. It slows markedly and needs low gears
- C. It accelerates faster when loaded
- D. It requires no gear change
Show answer
B. It slows markedly and needs low gears — Power to weight is poor, so the combination loses speed steadily and the driver plans lane position around holding up faster traffic.
Universal rule · checked against 49 CFR Part 380 Appendix F — Appendix F: LCV Required Knowledge and Skills · verified 2026-07-30
Why does an LCV need a longer gap to cross or enter traffic?
- A. Its horn cannot be heard
- B. The whole set clears the road slowly
- C. Its lights are dimmer than normal
- D. Its mirrors face backwards only
Show answer
B. The whole set clears the road slowly — The last trailer is still in the intersection long after the tractor has passed through, so the gap is judged from the rear of the set.
Universal rule · checked against 49 CFR Part 380 Appendix F — Appendix F: LCV Required Knowledge and Skills · verified 2026-07-30
How does an LCV's braking compare with a single-trailer combination?
- A. It relies on engine braking alone
- B. It brakes in the same distance
- C. It stops faster because of more axles
- D. It needs more distance and earlier input
Show answer
D. It needs more distance and earlier input — Weight and cumulative brake lag both work against the driver, so the pedal goes down earlier and more gently than a single combination needs.
Universal rule · checked against 49 CFR Part 380 Appendix F — Appendix F: LCV Required Knowledge and Skills · verified 2026-07-30
Why does an LCV take longer to inspect than a single combination?
- A. Its tyres need no inspection
- B. Every added trailer and dolly adds checks
- C. Its lights are checked at the depot
- D. Its brakes are sealed units
Show answer
B. Every added trailer and dolly adds checks — Each trailer brings its own brakes, lights, tyres and coupling, and each dolly is another hitch, chain set and pair of air lines.
Universal rule · checked against 49 CFR Part 380 Appendix F — Appendix F: LCV Required Knowledge and Skills · verified 2026-07-30
Frequently asked questions
How many questions are on the LCV Doubles test?
30 multiple-choice questions, and you need 80% correct — so you can miss 6. The federal standard is consistent across nearly every state.
Is this LCV Doubles practice test free?
Yes. Every practice test here and everything in the DMV Prep app is free — no ads, no paywall, no account.
Where do these questions come from?
The FMCSA Commercial Driver's License Manual and 49 CFR. Every question carries its citation, which you can open from the answer explanation.
