Louisiana Doubles & Triples (T) Practice Test
The endorsement for pulling two or three trailers. The test targets what changes when you add trailers: the crack-the-whip effect that amplifies every steering input at the last trailer, why the lightest trailer belongs in the rear, converter dollies and how coupling doubles differs from coupling a single, and the longer gaps and slower decisions that stability demands. It's knowledge-test-only — there's no separate skills test — but several states won't let you pull triples at all, so where you can use it depends on where you drive.
Who needs it: LTL linehaul and turnpike drivers pulling sets. Knowledge test only — no separate skills exam.
Sample practice questions
The ABS warning lamp on a trailer stays lit. This means:
Answer: ABS is not working on that trailer, but the normal brakes still work — A lit trailer ABS lamp means ABS isn't working on that unit; standard brakes still function — get it fixed.
To reduce rollover risk with doubles or triples, you should:
Answer: Steer gently and gradually, keep cargo low, and manage space — Gentle steering, a low center of gravity, and plenty of space are the three core rollover-prevention habits.
To check that air reaches the rear trailer, you:
Answer: Charge the system, open the emergency line shut-off valve at the rear of the last trailer (hear air escape), then close it — Hearing air escape at the rear emergency-line valve proves air made it all the way to the back trailer.
Common mistakes on the Doubles/Triples test
- Putting the heaviest trailer in the rear — the test (and physics) wants it behind the tractor
- Forgetting the dolly coupling sequence and the extra air-line connections doubles require
- Ignoring rearward amplification — the last trailer can flip from an input the tractor barely felt
- Assuming triples are legal everywhere — several states prohibit them entirely
The Doubles & Triples (T) endorsement has no federal ELDT requirement — it's a knowledge test only, so practice is the whole game.
Official source: Louisiana Office of Motor Vehicles
CDL licensing in Louisiana is administered by the Louisiana Office of Motor Vehicles. Fees, scheduling, forms, and the official Louisiana CDL manual live on the official site: Louisiana OMV — official CDL page (verified 2026-08-09).
Truckcess is not affiliated with or endorsed by the Louisiana Office of Motor Vehicles. Our practice tests cover the federal CDL knowledge standards (49 CFR Part 383) that every state exam is built on; exact question counts, fees, and procedures vary by state and change over time — the official site is always the authority.
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Full prep courses are one-time from $59 with 12 months of access — mytruckcess.com/cdl.
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