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.
Which of the following is part of the electrical and air lines coupling inspection?
2.
When a vehicle goes around a corner, the rear wheels follow a different path than the front. This is called:
3.
The likelihood of a fully loaded rig turning over compared to an empty trailer is:
4.
When you open the emergency shut-off valve at the back of the last trailer after supplying air to trailer(s):
5.
For proper hose coupling, lines are often color-coded. Service lines are usually:
6.
Hose couplers are also referred to as:
7.
A function of the tractor protection valve is:
8.
When traveling under 40 mph, how much distance should you leave, at minimum, from the car in front of you?
9.
Spring brakes are not required on trailers and dollies built before:
10.
Rearward amplification is a major cause of:
11.
If you have to enter another traffic lane to complete a wide turn, you should:
12.
When pulling trailers:
13.
The locking jaws should be around:
14.
Improperly greased or lubricated fifth wheels will cause:
15.
The emergency air line is usually what color?
16.
How much space should there be between the upper and lower fifth wheel?
17.
Rocky mountain doubles have a rearward amplification of about:
18.
To test the tractor protection valve, pump the brakes with the engine off until the trailer air supply knob pops out, usually at:
19.
While driving, you should use the trailer hand valve when?
20.
A specific item to check on a sliding fifth wheel is: