Ohio 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

After the dolly is under and locked to the rear trailer, you connect:

Answer: Safety chains, air hoses (glad hands), and the light cord — Connect the safety chains, the air hoses (glad hands), and the electrical/light cord between the dolly and the rear trailer.

Glad hands are:

Answer: Air-line coupler fittings that must be clean and seal properly — Glad hands join the air lines; keep them clean, sealing, and not crossed.

After backing the dolly under the rear trailer, you should raise the rear trailer's landing gear:

Answer: Slightly off the ground so the trailer isn't damaged if it moves — Raise it just slightly during coupling to prevent damage if the trailer shifts.

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: Ohio Bureau of Motor Vehicles

CDL licensing in Ohio is administered by the Ohio Bureau of Motor Vehicles. Fees, scheduling, forms, and the official Ohio CDL manual live on the official site: Ohio BMV — official CDL page (verified 2026-08-09).

Truckcess is not affiliated with or endorsed by the Ohio Bureau 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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