Doubles/Triples
20 original practice questions across 4 topics. Every answer comes with a written explanation and a citation to the actual federal regulation, not just an answer key.
Study by topic
Frequently asked questions
What does the Doubles/Triples CDL test cover?
The Doubles/Triples knowledge test covers 4 required topics, including Pulling Double/Triple Trailers, Coupling and Uncoupling, and Inspecting Doubles and Triples. These are the required knowledge areas under 49 CFR 383.115. Practicing by topic here lets you see exactly which areas you're weak on before test day.
How many practice questions does the Doubles/Triples section have?
This section has 20 original practice questions across 4 topics, each with its own written explanation and a citation to the actual regulation behind it. Your state's real test uses its own question count; Washington, for example, uses 20 questions for its Doubles/Triples test.
Are these the real Doubles/Triples CDL test questions?
No. These are original practice questions, not the actual Doubles/Triples exam questions used by any state. They're derived from the federal knowledge requirements in 49 CFR 383.115, never copied from a real test or a competitor's practice test, and each comes with its own written explanation.
What does the Doubles/Triples endorsement knowledge test cover?
It covers assembling and hooking up multiple trailers, placing the heaviest trailer correctly, handling and stability characteristics like off-tracking and rollover risk, and traffic-operation challenges such as longer passing times, under 49 CFR 383.115. These are the specific knowledge areas required to add this endorsement to your CDL.