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Free Colorado CDL Combination Practice Test 2025
Part of mandatory Entry-Level Driver Training Course Based on 2025 CO commercial driver's license manualAvailable in EN, ES
25questions
5mistakes allowed
80%passing score
Welcome! You’re probably here because you want to pass the official Combination Vehicles knowledge test on the theory of operating combination vehicles, which you must do to be allowed to drive semi-trucks and tractor-trailers. We hope you’ve been reading the official Colorado Commercial Driver License Manual (Colorado CDL Handbook 2025), especially Section 6 (Combination Vehicles), because the official knowledge test is based on it. But are you also looking for some additional help to improve your chances of passing the test?
Well, that’s what we’re here for! We’ve helped thousands of aspiring car drivers and commercial drivers pass their respective knowledge exams, and we’re going to help you too.
This free Colorado CDL Combination practice test, one of several we offer, is based on the above official study guide, just like the official Combination Vehicles knowledge test. The practice test is up to date as of January, 2025. As you practice answering questions about the stuff you’ve been reading in the manual, that material will become easier to remember, increasing your chances of passing the official exam. To make your learning easier, each of the 25 practice questions comes with a helpful hint and an explanation of the correct answer. The practice questions and answers on this test will assess your knowledge of such topics as safe driving techniques, combination braking systems, coupling and uncoupling, and pre-trip inspections. If you need help to answer a question, our automated assistant can give you a hint. If you still miss the question, the assistant can provide you with an explanation of the correct answer.
Once you obtain a Commercial Learner’s Permit (CLP), you can start practicing commercial driving of combination vehicles until you get good enough to pass the official skills test. Passing the skills test in a combination vehicle is a necessary step toward obtaining a Class A Commercial Driver’s License (CDL).
Once you hold a Class A CDL, you can start earning real money as a licensed driver of combination vehicles. Economic sectors in Colorado’s diversified economy include agriculture (hay, corn, wheat, and beef), aerospace, manufacturing, and gold mining and production. All these sectors need truck drivers to transport their products. The aerospace and mining industries also need truck drivers to deliver equipment and supplies to them.
You’ll soon become familiar with Colorado’s major truck routes. Here are some. Interstate 25, heavily used by truckers, runs from Wyoming through Denver and then to New Mexico. Interstate 70 runs from Utah to Maryland. Interstate 76 and U.S. Route 285 are heavily used by truckers to transport agricultural products.
Perfect for
- First-time CO CDL and CLP applicants
- CDL holders adding endorsements
- CO CDL renewal applicants
What to expect on the actual exam
| How many questions | 20 |
|---|---|
| How many correct answers to pass | 16 |
| Passing score | 80% |
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List of questions (classic view)
- After you lock the kingpin into the fifth wheel, how should you check the connection?
- After you connect the air lines but before you back under the trailer, you should
- Which statement best illustrates the "crack-the-whip" effect?
- When you inspect the landing gear after uncoupling the trailer, where should the tractor be?
- What is the safest way to turn right from a two-way road?
- To drive a triple combination vehicle, you must have
- To prevent a rollover, cargo should be
- Combination vehicles take longer to stop when they are empty than when they are fully loaded, because
- If your vehicle gets stuck on a railroad track, you should
- Low-slung vehicles can be risky at railroad crossings because
- On a double or triple vehicle, which wheels offtrack the most?
- When you're pulling doubles or triples, the shut-off valves should always be
- On a trailer, where is the yellow antilock brake (ABS) malfunction lamp located?
- Even before antilock braking systems (ABS) were required, some vehicles already had them. How can you check if your vehicle has ABS?
- An antilock braking system (ABS) is useful
- After coupling, make sure that the air lines are not crossed. How should you do this?
- During uncoupling, you should disconnect the electrical cable and
- Before you start to uncouple, you must
- You can confirm that air is going to all brakes in your trailers by
- To uncouple a loaded trailer, after the landing gear has made firm contact with the ground, you should
- If the trailer has antilock brakes (ABS) but the tractor doesn't,
- To test the tractor protection valve, charge the trailer air brake system, turn off the engine, and
- If your test of the tractor protection valve is successful,
- The tractor protection valve is designed to close automatically if the air pressure falls into the pressure range specified by the manufacturer, typically
- As part of your vehicle inspection test, if your vehicle is equipped with air brakes and has a trailer, you will inspect the air connections between the truck or tractor and the trailer. Make sure that the ________ are locked in place and free of damage or air leaks.
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