Safety & Trades Practice Questions
CDL Practice Questions
Commercial Driver's License General Knowledge Test — Free cdl practice test questions covering general knowledge, vehicle inspection, air brakes, basic vehicle control, and safe driving. Every question includes a full explanation so you actually learn the material, not just the answer.
50
Total Questions
Untimed
Time Limit
80% (40/50)
Passing Score
$10-$100 (varies by state)
Registration Fee
Free Sample Questions
Here are 5 free sample questions from our full bank of 400+ CDL practice questions. Try them out below — click "Show Answer" to reveal the correct response and explanation.
1
During a pre-trip inspection, you notice that one of your tires has a tread depth of 2/32 of an inch on a front steering tire. What should you do?
AA) Drive carefully and replace it at the next stop
BB) Add air pressure to compensate for the wear
CC) Do not drive the vehicle until the tire is replaced
DD) Rotate the tire to the rear axle and continue
2
When backing a commercial vehicle, which practice is safest?
AA) Back toward the driver's side whenever possible
BB) Rely only on your mirrors without getting out
CC) Back quickly to minimize time in the travel lane
DD) Honk the horn once and proceed without looking
3
You are driving a heavy vehicle on a downgrade. Which technique helps prevent brake failure?
AA) Pump the brakes rapidly the entire way down
BB) Shift to neutral to let gravity carry the truck
CC) Ride the brakes lightly and continuously
DD) Select a low gear before starting down and use engine braking
4
What does it mean when a low air pressure warning activates in a vehicle with air brakes?
AA) The parking brake has failed completely
BB) Air pressure has dropped below about 60 psi and you must stop safely and park
CC) You need to accelerate to build more air pressure
DD) The trailer brakes are fully applied
5
Which of the following is required in the pre-trip inspection report if no defects are found?
AA) The driver must still sign the report
BB) No report is needed at all
CC) Only the carrier signs it
DD) A mechanic must countersign the report
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About the CDL
Format & Structure
- Total Questions
- 50
- Time Limit
- Untimed
- Format
- Written at DMV
Scoring & Cost
- Passing Score
- 80% (40/50)
- Registration Fee
- $10-$100 (varies by state)
Related Practice Questions
Frequently Asked Questions
What are the different CDL classes?
There are three classes. Class A covers combination vehicles with a gross combination weight over 26,000 pounds, where the towed unit is more than 10,000 pounds -- think tractor-trailers. Class B is for single heavy vehicles like dump trucks, straight trucks, and most buses. Class C covers smaller vehicles that still require a CDL because they carry 16+ passengers or haul hazardous materials. Most long-haul drivers go for a Class A because it's the most flexible.
What CDL endorsements should I consider?
Endorsements let you operate specific equipment or haul specific cargo. The common ones are H (hazardous materials), N (tank vehicles), P (passenger), S (school bus), T (doubles/triples), and X (a combo of H and N). Each endorsement adds a knowledge section on your written test, and some, like H, require a TSA background check. Pick endorsements that match the jobs you actually want -- don't pay for ones you'll never use.
Do CDL requirements vary from state to state?
Yes, to a point. The federal government sets the floor through FMCSA rules, so the core knowledge is the same everywhere. But states handle the fees, scheduling, medical card submission, and some of the road skills details on their own. Fees range from roughly $10 in some states to over $100 in others. Always check your state DMV site for the exact process before you start.
What's the difference between the written test and the skills test?
The written (knowledge) test is a multiple-choice exam you take at the DMV. It covers general knowledge, air brakes, and any endorsements you're going for. Pass that, and you earn a Commercial Learner's Permit (CLP). After holding the CLP for at least 14 days, you can take the skills test -- that's the hands-on part with a pre-trip inspection, basic control maneuvers, and an on-road drive. Both have to be passed to get your CDL.
How detailed does the pre-trip inspection need to be?
Very detailed. During the skills test, examiners expect you to point to each component, name it, and explain what you're checking for -- cracks, leaks, loose bolts, proper mounting, and so on. You'll walk through the engine compartment, cab, lights, tires, brakes, coupling system, and trailer. Most students spend more study time here than anywhere else, because missing items costs points fast.
How long should I study for the CDL general knowledge test?
Most people study somewhere between two and six weeks. If you can read your state's CDL manual cover-to-cover and run through practice questions every day, two weeks is realistic. If you're juggling a job or finding the material new, give yourself a month or more. Consistency beats cramming here -- short daily sessions stick better than one long weekend push.
What are the retake rules if I fail the CDL test?
Retake rules are set by each state. Most let you retake the knowledge test the next business day, though some require a short waiting period of one to seven days. You'll usually pay a retest fee each time. For the skills test, states often limit you to three attempts before requiring additional training. Check your local DMV for the exact policy -- and use the time between attempts to fix whatever tripped you up.
What is ELDT and do I need it?
ELDT stands for Entry-Level Driver Training. Since February 2022, anyone applying for a first-time Class A or Class B CDL, upgrading from B to A, or getting a first-time P, S, or H endorsement must complete ELDT through a provider on the FMCSA's Training Provider Registry. The training has both a theory portion and behind-the-wheel hours. You have to finish ELDT before you're allowed to take the CDL skills test.
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