Free District of Columbia CDL Combination Vehicles Practice Test 2022

You have to pass the CDL combination vehicles endorsement to get ready for propelling your career with your license. You are looking for a good DC CDL practice test source for your coming CDL test? You are in the right place. Our practice test is a great resource for beginners. The CDL practice test is designed for you to have exactly the experience of the exam as you will be more familiar with both the test format and the subject. They cover topics ranging from combination vehicle maintenance to safely driving a complex rig. Each question is based on the official DC CDL Manual so you can be sure that the information in our test is accurate and relevant to your examination. In addition, each question has a detailed explanation so that it is very useful for you to learn from your mistakes. Preparing well before test day with questions and content that we cover. Start with our Free District of Columbia CDL Combination Vehicles Practice Test today and walk out with your endorsement!

Our CDL practice tests:
Based on 2022 DC commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
DC CDL Combination Vehicles Test format:
20 questions
16 correct answers to pass
80% passing score
List of questions
1.
The air lines on a combination vehicle are often colored to prevent them from mixing up. The emergency line is _____, the service line is _________.
2.
After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in what position?
3.
The higher the center of gravity of your truck, the:
4.
The shut-off valves at the back of the last trailer should be:
5.
After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is done by:
6.
The trailer service brakes should be tested with the hand control, and controlled during normal operation by:
7.
There are two things that a driver can do to prevent a rollover. They are: (1) keep the cargo as close to the ground as possible and (2):
8.
To help prevent rollover, keep the center of gravity of the load as low as possible, and:
9.
A major leak in the trailer emergency line will cause:
10.
When driving a combination vehicle with multiple trailers or dollies, all air shut-off valves except the last one at the back must be:
11.
To stop other drivers from passing you on the right when turning wide:
12.
The trailer hand valve should be used:
13.
The emergency air line controls the emergency brakes on combination vehicles, and:
14.
If the wheels of the trailer lock up and the trailer swings around, it could cause a:
15.
Converter dollies:
16.
You are coupling a tractor to a semitrailer and have backed up, but are not under it. What should you hook up before backing under?
17.
In normal driving, some drivers use the hand valve before the brake pedal to prevent a jack-knife. Which of the statements is true?
18.
After you have coupled the trailer you should raise the landing gear by using:
19.
What gear should the tractor engine be in after you uncouple the trailer and are inspecting the trailer supports?
20.
While checking if the trailer is securely coupled to the tractor, the landing gears should be: