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Free CO CDL Double/Triple Trailers Practice Test 2025

  • Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
  • Based on 2025 CO commercial driver's license manual
  • Triple-checked for accuracy
  • Updated for October 2025

Did you know that in Colorado you cannot tow more than one trailer or vehicle unless it’s for commercial purposes and you have obtained the Double/Triple Trailers endorsement? If you’re looking to add this endorsement on your Colorado Commercial Driver’s License (CDL), the key requirement is passing a 20-question multiple-choice knowledge test. The test requires a score of 80% (or 16 correct answers) to pass. Once you’ve achieved this certification, you receive a “T” endorsement on your CDL, which authorizes you to pull two or three trailers (where legal) and operate combination vehicles that require this added skill and knowledge (Colorado CDL Handbook 2025).

This endorsement covers double pup trailers, which are legal throughout the United States. Adding this credential significantly enhances your CDL, making you capable of transporting more freight and immediately more marketable in the industry. Goods that are often shipped by way of double trailers in Colorado include agricultural products, industrial goods, consumer goods, and Colorado’s natural resources like coal and timber. You may be saying to yourself, “That sounds incredible! But how can I best prepare for this test?”

There is an abundance of online resources, but too much information can be overwhelming. What you need is a clear and systematic approach, which is where our online Colorado CDL Double/Triple Trailers practice test comes in. It is up to date as of October 2025 and includes 20 multiple-choice questions that resemble what you will face at the DMV on your actual test day!

As you work through our online practice test, you’ll receive instant and detailed feedback on your answers. If you make a mistake, you’ll immediately see the correct answer along with a clear explanation of why it is the better choice. This method reinforces the material in real-time, instead of bombarding you with the entire assessment at the end.

Colorado only requires the passing of this knowledge test in order to add the “T” endorsement to your already existing Class A or Class B CDL. Once you have prepared, passed our free practice tests, and feel ready to go, you simply apply at the DMV, provide the required documentation, and pay the fee prior to taking the official test.

Looking for other Colorado-based CDL endorsements? Find tons of valuable information and practice tests here.

Pass the first time with Premium
CO commercial driver's license
  • Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
  • Triple-checked for accuracy

What you need to know

4.75 out of 5 • 4 votes
6 min to complete
Available in EN and ES
Verified by Steven Litvintchouk, M.S., Chief Educational Researcher, Member of ACES. See our detailed commitment to accuracy and quality in our practice tests.
Ensuring the accuracy and quality of our program is paramount. Learn more about our rigorous standards in our Commitment to Accuracy article.

What to expect on the actual CO DMV exam

20

questions

16

correct answers to pass

80%

passing score

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