Free practice test
CDL Doubles/Triples practice test
The free test below follows the real Doubles/Triples test: 20 questions, 16 right to pass, about 20 minutes. It is a short test about handling more than one trailer.
FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.
How the Doubles/Triples test is scored
You need 16 of 20 right, which is 80%. That means you can miss 4. Drivers who want the T endorsement to pull doubles or triples. There is no extra skills test or background check for it beyond the written test.
What is on the Doubles/Triples test
- Pulling doubles and triples: space, speed and turns
- Rearward amplification, also called crack the whip
- Coupling and uncoupling twin and triple trailers
- Inspecting the converter dolly and the extra coupling points
- Which trailer goes where
What trips drivers up
Rearward amplification
Each trailer adds to the swing. The last trailer swings the most in a sudden lane change, so steer gently.
Trailer order
Put the heaviest trailer in front and the lightest at the rear.
Coupling steps
Doubles add a converter dolly. The test asks about the steps for using it.
Rollover
More trailers means more risk in a curve. Slow down before you enter it.
Numbers come from the CDL manual and federal rules. A few differ by state or manual edition, so check your own state's manual. See our sources.
More practice tests
Common questions
How many questions are on the CDL Doubles/Triples test?
The national default is 20 questions, and you need 16 right (80%) to pass.
Do I need Combination Vehicles to take Doubles/Triples?
You need a Class A license, which means you have passed or are taking the Combination Vehicles test. Ask your state about the order.
What is a converter dolly?
It is a small frame with a fifth wheel that lets you hook a second trailer behind the first.
Is there a skills test for Doubles/Triples?
Many states do not require one beyond the written test. Check your state's rules.