Free practice test
Free CDL Practice Test
Take our free CDL practice test with 20 questions covering general knowledge, air brakes, and combination vehicles. Instant scoring with explanations.
- 100% free to practice
- No signup required
- State-specific content
This free CDL practice test includes 20 multiple-choice questions drawn from the subject areas covered on the CDL general knowledge test, air brakes test, and combination vehicles test. Topics include vehicle inspection, air brake system components and checks, coupling and uncoupling procedures, and driver qualification requirements.
After you submit, you will see your score, the correct answer for each question, and a plain-English explanation. Use missed questions to identify the areas you need to review before your exam.
These questions are for study practice only and are not official exam questions. ExamsLib is not an official licensing or certification authority. Passing this practice test does not guarantee a passing score on any exam.
These questions are for study practice only and are not official exam questions.
Question 1
Question 2
Which of these should a driver check during a pre-trip inspection of the engine compartment?
Question 3
During a pre-trip inspection, why should a driver check tire tread depth?
Question 4
What should a driver do if a pre-trip inspection reveals a cracked windshield that blocks the view?
Question 5
What is the purpose of mirrors on a large commercial vehicle?
Question 6
How often should a driver check mirrors while driving a commercial motor vehicle?
Question 7
What is a 'blind spot' on a large commercial vehicle?
Question 8
Why do large commercial vehicles have bigger blind spots than passenger cars?
Question 9
What should a driver do before changing lanes in a commercial motor vehicle?
Question 10
What is the purpose of using turn signals well before a turn or lane change?
Question 11
When should a driver use the horn as a way to communicate on the road?
Question 12
What does 'space management' mean for a commercial driver?
Question 13
Why do commercial motor vehicles need more following distance than passenger cars?
Question 14
As a general rule of thumb, how many seconds of following distance should a driver maintain at speeds below 40 mph, based on vehicle length?
Question 15
According to the following-distance rule of thumb, what should a driver do when traveling above 40 mph?
Question 16
What is 'space cushion' driving?
Question 17
Why should a driver reduce speed when approaching a curve in a large commercial vehicle?
Question 18
What is 'hydroplaning'?
Question 19
What should a driver do to help prevent hydroplaning in wet weather?
Question 20
Why is night driving generally more hazardous than daytime driving?
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Frequently asked questions
What topics does this CDL practice test cover?
The practice test covers general knowledge topics such as vehicle inspection and driver qualifications, air brake system components and brake check procedures, and combination vehicle topics such as coupling, uncoupling, and the fifth wheel.
Is this practice test the same as the real CDL knowledge test?
No. These questions are for study practice only and are not official exam questions. The real CDL knowledge test is administered by your state's driver licensing agency or its approved testing provider. ExamsLib is not an official licensing authority.
How many questions are on the real CDL general knowledge test?
It varies by state. Most states use 50 questions, but Illinois uses 30 and Pennsylvania uses 70 for Class A (50 for Class B or C). The federal passing score is 80 percent everywhere. Confirm the current format with your state's driver licensing agency before your exam.
Do I need an account to take this practice test?
No account or login is required. The practice test is completely free and your results are saved locally in your browser.
