Combination
All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice questions, and applicants will have one hour to correctly answer a minimum of 16 questions. The Combination test is not a replacement for the Double/Triple endorsement test.
8. To prevent a trailer from rolling over, you should:
To reduce the risk of a rollover when driving a combination vehicle, you should keep the weight of the cargo as low to the ground as possible and drive slowly around turns.
9. When the wheels of a trailer lock up:
A trailer may swing out and strike other vehicles if its wheels lock up. This is especially likely with lightly-loaded trailers.
10. If unsure if a trailer is equipped with ABS, you can:
Trailers and converter dollies built on or after March 1, 1998 are required to have Anti-Lock Braking Systems (ABS). This will be indicated by the presence of a yellow malfunction lamp. You can determine if older trailers have ABS by checking under the trailers for ECU and wheel speed sensor wires coming from the back of the brakes.
11. Which of the following types of vehicles is most prone to the “crack-the-whip" effect?
Double and triple combinations are the most vulnerable to turning over as a result of the "crack-the-whip" effect.
12. A shut-off valve:
Shut-off valves are used in air supply lines to control the passage of air from one trailer to another. The rear shut-off valve should always be closed to prevent air from leaving the braking system.
13. Using the trailer hand brake while experiencing a trailer jackknife will:
If you are experiencing a trailer jackknife, you can help your tires regain traction by releasing the brakes. Using a trailer hand brake while experiencing a skid will only cause the skid to continue.
14. In a sudden turn, the ____ trailer is the most likely to turn over.
When making a turn, be sure to steer gently and smoothly. Making a quick turn while pulling trailers is dangerous and can increase the risk of the last trailer rolling over.
See the exact questions that will be on the 2024 District Of Columbia DMV exam.
99.2% of people who use the cheat sheet pass the FIRST TIME
Alexa shares with us how she went in for her Class A permit and decided to get her Hazmat endorsement as a bonus!
Mark shares his feedback on his Class A CDL Cheat Sheet
