Based on 2024 DC commercial driver's license manual
Free District of Columbia CDL Combination Practice Test 2024
This CDL practice test is a great place to start if you’re after the DC Combination Vehicles endorsement. Each of the 25 questions is based on the official 2024 CDL manual. The test is designed to prepare you for the Combination Vehicles portion of your 2024 Commercial Driver’s License exam. There are several answer options, but only one of them is correct. Every time you answer a question, you’ll get immediate feedback with a detailed explanation, so you won’t need to wait until the end of the test to know the correct answers.
Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
Triple-checked for accuracy
What you need to know
9 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.
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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Our commitment to accuracy and quality in our practice tests
Explore our rigorous, multi-tiered verification process that ensures each question mirrors the official manual for unparalleled accuracy.
Written by Andrei ZakhareuskiUpdated over a week ago
At Driving-Tests.org, we understand the importance of reliable and accurate practice tests to help you prepare for your DMV exam. That's why we've developed a meticulous process to create and continually update our practice questions, ensuring they reflect the most current driving laws and regulations.
Here's an inside look at how we maintain the highest quality in our practice tests.
Content Creation and Verification Process
Alignment with Official Manuals: Every question we develop is based on the most recent version of each state's official driving manual. Our team regularly monitors each state DMV's website for the latest updates to ensure our practice tests are always aligned with the most current information.
Community Feedback Integration: We leverage feedback from our vast community of users to understand which topics are most frequently tested. This helps us focus on the areas that are most relevant and beneficial for your preparation.
Expert Content Creation: Our in-house editor, Steven, who has extensive experience in driver education, crafts each question with precision. He conducts a thorough review of each question against the official manuals to ensure accuracy.
Rigorous Review Process: Once Steven has finalized a set of questions, our team conducts a joint review session. This second level of scrutiny involves content accuracy, proofreading, and fact-checking to eliminate any errors.
User Feedback Mechanism: After a question goes live on our site, we keep the lines of communication open. Each question features a feedback button, inviting users to report any issues or errors. This continuous feedback loop allows us to address and rectify any concerns promptly.
Responsive Updates: In line with our commitment to accuracy, we quickly update our practice questions to reflect any changes in the DMV manuals. Additionally, we update the free electronic copy of the state's driver's license manuals on our site, typically within a few days after the DMV publishes them.
Our thorough quality control process ensures that you have access to practice tests that are as accurate and up-to-date as possible. We believe in the power of well-prepared drivers and are dedicated to providing you with the best study tools to help you succeed on your DMV exam.
