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FREE Ontario Class A Licence Test 2025 | ON

Based on the 2025 ON CDL manual
Questions: 50
Mistakes allowed: 10
Passing score: 80%
Ensuring the accuracy and quality of our practice tests is paramount. Learn more about our rigorous standards in our Commitment to Accuracy article.

Preparing to drive a semi-trailer truck or a long combination vehicle in Ontario? You’ll need a Class A commercial driver’s licence. The transportation industry in ON is booming, so now is a great time: truck drivers are in high demand. As a Class A licenced commercial driver, you can work for a trucking company as an employee, or for yourself as an owner-operator. But in order to drive one of the largest vehicles on the road, you must first learn to drive carefully and safely. So before you can get your Class A licence, you must pass both a written and a practical test. The written test (also known as the Ontario truck driver’s knowledge exam) has several multiple-choice questions. This 50-question Class A practice test is a great way to prepare as all questions are based on the official 2025 ON commercial driver’s manual. As you answer the questions, we recommend checking each question’s explanation to gain some further insight into the rule behind it. Good luck and drive safely!

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Based on 2025 ON commercial driver's license manual
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List of questions (classic view)
  1. What must you do at a stop sign with a painted stop line?
  2. Over-braking with a trailer can sometimes lead to
  3. What does this sign tell you?
  4. When is a pre-trip inspection required?
  5. What gauges should you check after starting your vehicle?
  6. Which valves make up the tractor protection system?
  7. When coupling a tractor to a semitrailer,
  8. What does this sign mean?
  9. In an air brake system, what is brake lag time?
  10. What does this sign mean?
  11. Before driving down a grade (hill), you should
  12. When inspecting the brake chambers, you should check for which of the following?
  13. The supply line is also called
  14. When brakes become overheated, they also become
  15. Which belts should you check during your pre-trip inspection?
  16. What is the purpose of the National Safety Code?
  17. What is a normal reaction time for a driver?
  18. Most manufacturers of commercial vehicles recommend draining the moisture and oil from an air brake system on a ________ basis.
  19. What is the Gross Vehicle Weight Rating (GVWR)?
  20. Which of these is not a part of a drum brake?
  21. What is the purpose of the slider on a trailer?
  22. What is the most common cause of air loss in a trailer?
  23. What is brake lag time?
  24. What does this sign mean?
  25. Why is it important to know which parts of the air brake system exhaust air?
  26. What's the proper way to confirm that a vehicle passed its annual inspection?
  27. While on duty, under which circumstances can a police officer or appointed ministry officer conduct a safety inspection on your vehicle?
  28. What is an essential component of a well-documented daily inspection report?
  29. As a driver, you are responsible for ensuring that which of these is secured on your vehicle?
  30. A front tire fails the inspection if the tread depth on two adjacent grooves anywhere on the tire is less than
  31. How much uninterrupted off-duty time must a driver take after clocking 13 hours of driving time?
  32. Choose the odd one out: Which of the following is not a recommended safety measure before reversing a vehicle?
  33. When coupling your tractor to a trailer, after you raise and secure the landing gear, what do you do next?
  34. When coupling your tractor to a trailer, once the jaws lock onto the kingpin, what should you do next?
  35. You stopped on an uphill grade. When resuming traffic, what should you do?
  36. Which of these is most important to check underneath the hood?
  37. What does this sign refer to?
  38. What is the crucial requirement when reversing the tractor to couple it with the trailer?
  39. What is the maximum allowable length for a combination vehicle?
  40. The speed limiting system in many commercial vehicles is set to restrict the maximum speed to
  41. How are the dangerous goods being transported on Ontario roads identified?
  42. What must you do if you discover a minor defect during a trip?
  43. Which of the following activities is considered off-duty?
  44. To avoid your vehicle's wheels going over the curb or sidewalk while making a right turn, what should you do?
  45. If after inspecting your vehicle, you find out that the brake lamps aren't functioning, what action should be taken?
  46. Who can demand you to appear at a truck inspection station?
  47. Before putting your vehicle in reverse gear, what should you do?
  48. If a repair technician has installed new wheel fasteners on your vehicle,
  49. You are prohibited from operating a commercial vehicle if you've been on-duty for how many hours in a week?
  50. How should you enter a roundabout?