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.
When a vehicle goes around a corner, the rear wheels follow a different path than the front. This is called:
2.
You should not back a tractor under a trailer until the air system is:
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.
Hose couplers are also referred to as:
6.
When traveling under 40 mph, how much distance should you leave, at minimum, from the car in front of you?
7.
Rearward amplification is a major cause of:
8.
You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You expect the trailer brakes to come on and:
9.
If you have to enter another traffic lane to complete a wide turn, you should:
10.
There are two things that a driver can do to prevent a rollover. They are: (1) go slow around turns, and (2):
11.
The locking jaws should be around:
12.
When should you use the hand valve to park a combination vehicle?
13.
Improperly greased or lubricated fifth wheels will cause:
14.
When checking the trailer emergency brakes, the tractor protection control valve should be placed in what position?
15.
How much space should there be between the upper and lower fifth wheel?
16.
You have a major leak in the service line, and you put on the brakes. Service air will escape and cause the:
17.
The safety latch for the fifth wheel locking lever must be _____ for a coupling to be complete.
18.
Your emergency air line breaks or gets pulled apart while you are driving. The loss of pressure will cause the:
19.
The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:
20.
Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?