General Driving Knowledge — Ontario

Ontario commercial knowledge test practice: 242 free practice questions (Based on the official driver handbook). The official format is not yet verified; check the official site before your test. General Driving Knowledge: 63 questions. Updated

Questions that do not fit a single topic: lane use, turning, signalling and other rules of the road.

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Topic / MetricValue
TopicGeneral Driving Knowledge
License testOntario Commercial knowledge tests (Class A–F, Z air brake)
Topic questions63 (26% of 242 total)
Review statusThis topic page is still being reviewed against the official handbook. Until review is finished it is hidden from search engines.

Official handbook

Not yet verified Official MTO Truck / Bus / Air Brake handbooks link not yet collected

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Questions (63)

1. Can medical professionals be legally obligated to report your health issues that could impact your driving abilities?
  1. Only in severe cases
  2. No
  3. Only if it affects your vision
  4. Yes ✓

Answer: D. Yes

Yes — medical professionals can be legally required to report health conditions that might affect your driving. The handbook says doctors must report to the Ministry the names and addresses of anyone 16 or older with a condition that may affect safe driving, such as a stroke, heart condition or dizziness. It also says medical practitioners or optometrists are required by law to report physical, neurological, cardiovascular or other conditions that might affect safe operation of a motor vehicle. That supports yes: reporting is a legal duty, and your licence may be suspended until new medical evidence shows the condition does not pose a safety risk.
Official handbook: Official MTO Truck Handbook, Other ways to lose your licence – Medical suspension
2. When applying for a licence to drive a bus, do you need to submit a filled out ministry medical certificate?
  1. Only if you are under the age of 46
  2. Only if you are over the age of 64
  3. Yes ✓
  4. No

Answer: C. Yes

Official handbook: Official handbook
3. While the bus is stationary, where should a bus driver continue to look?
  1. Only at the traffic beside
  2. Only at the traffic ahead
  3. At the traffic ahead, beside, and in the vehicle mirrors ✓
  4. Only in the mirrors

Answer: C. At the traffic ahead, beside, and in the vehicle mirrors

While the bus is stationary, the driver should keep looking at the traffic ahead, the traffic beside, and the vehicle mirrors. The handbook's traffic check says that while you wait, you keep an eye on the traffic around you — ahead, beside, and in the mirrors — so you notice changes in conditions. It does not limit the check to one direction. That matches the choice that includes ahead, beside, and mirrors together.
Official handbook: Official MTO Truck Handbook, Intersections – Stopping
4. Why is it important for a driver to regularly check all vehicle systems throughout the day for defects?
  1. Because the vehicle can wear out over time
  2. Because new defects can occur at any time
  3. Because the condition of the vehicle can change
  4. All of the above ✓

Answer: D. All of the above

All of the above: regular checks matter because the vehicle can wear over time, new defects can appear at any time, and its condition can change during the day. The truck handbook says a driver must inspect the vehicle every 24-hour period and keep monitoring its condition throughout the trip. It also describes an inspection schedule listing vehicle systems and components, with major and minor defects and rules for recording, reporting and repairing them. That supports checking during the day: the morning circle check is not the end of the story, and defects can show up later. Wear over time is the broader reason the inspection schedule exists.
Official handbook: Official MTO Truck Handbook, Daily trip inspection — classes A and D
5. When you test the system air-loss rate, the maximum acceptable leakage rates per minute after the initial drop are
  1. 7 kPa (1 psi) for single vehicles and 21 kPa (3 psi) for tractor-trailers.
  2. 34 kPa (5 psi) for single vehicles and 69 kPa (10 psi) for tractor-trailers.
  3. 34 kPa (5 psi) for single vehicles and 41 kPa (6 psi) for tractor-trailers.
  4. 21 kPa (3 psi) for single vehicles and 28 kPa (4 psi) for tractor-trailers. ✓

Answer: D. 21 kPa (3 psi) for single vehicles and 28 kPa (4 psi) for tractor-trailers.

The maximum acceptable leakage is 21 kPa (3 psi) per minute for a single vehicle and 28 kPa (4 psi) per minute for a tractor-trailer. The MTO air brake chart sets a different allowable drop for each vehicle combination. A straight truck, tractor or bus may lose no more than 21 kPa (3 psi) in one minute; a tractor with a trailer may lose no more than 28 kPa (4 psi). The test is done with normal pressure, engine off, spring brakes released and the service brake held fully applied. The initial pressure drop when you first apply the brake is not part of the leak-rate result; what matters is whether the pressure keeps falling faster than the chart allows.
Official handbook: Official MTO Air Brake Handbook, Inspecting Air Brake System Operation – Testing system air-loss rate
6. What is the maximum allowable length for a combination vehicle?
  1. 20 meters (66 feet)
  2. 23 meters (75 feet) ✓
  3. 25 meters (82 feet)
  4. 30 meters (98 feet)

Answer: B. 23 meters (75 feet)

The maximum allowable length for a standard combination vehicle is 23 metres (about 75 feet). The truck handbook sets a general ceiling: no combination of vehicles may be longer than 23 metres, which it gives as 75.5 feet. It then makes an exception for double-trailer rigs that satisfy special conditions for the trailers and tractor. That makes 23 metres the figure to choose for the normal combination limit. The listed 75 feet is a rounded version of the handbook's 75.5 feet, so it matches the bank answer.
Official handbook: Official MTO Truck Handbook, A and D licence classes and requirements – Size and weight limits for commercial motor vehicles
7. Polarized gladhands on a tractor
  1. cannot be connected to trailers built before 1975.
  2. can be incorrectly connected to non-polarized trailer couplers. ✓
  3. can be incorrectly connected to polarized trailer couplers.
  4. cannot be incorrectly connected to non-polarized trailer couplers.

Answer: B. can be incorrectly connected to non-polarized trailer couplers.

Polarized gladhands on a tractor can be incorrectly connected to non-polarized trailer couplers. The handbook explains that the supply and service couplers look much alike, so cross-connection is possible. Most couplers are designed to fit only their matching coupler, but some have no feature to prevent cross-connection. A polarized gladhand has the matching feature; it can still be wrongly joined to a trailer coupler that lacks that feature. That is why the bank answer points to non-polarized trailer couplers as the place where incorrect connection can happen.
Official handbook: Official MTO Air Brake Handbook, Trailer Brake Subsystem – Connecting a trailer
8. How can you avoid the risk of the rear wheels dropping off the pavement when going around a right curve?
  1. Keep the front wheels close to the left side of the lane ✓
  2. Weave back and forth within your lane
  3. Move into the left lane
  4. Keep the front wheels close to the right side of the lane

Answer: A. Keep the front wheels close to the left side of the lane

Keep the front wheels near the left edge of your lane when going around a right curve. The handbook explains that rear wheels do not steer with the front wheels and follow a tighter path, so a truck cuts inside a curve. On a right-hand curve, you lead the turn by holding the front wheels toward the left side of your lane. That leaves room for the rear wheels to stay on the pavement instead of dropping off the right edge. This is why the answer about the left side of the lane fits the handbook.
Official handbook: Official MTO Truck Handbook, Steering (forward) and off-track
9. What is the most common cause of air loss in a trailer?
  1. Leaky tractor protection valve
  2. Leaky supply tank
  3. Leaky glad hand seals ✓
  4. Defective governor

Answer: C. Leaky glad hand seals

Official handbook: Official handbook
10. Choose the odd one out: Which of the following is not a recommended safety measure before reversing a vehicle?
  1. Switch off the radio or phone
  2. Tell the operator in advance ✓
  3. Roll down the windows
  4. Blow the horn

Answer: B. Tell the operator in advance

Telling the operator in advance is not one of the safety measures the handbook lists before reversing. The backing section sets out a short routine to follow before you reverse: silence the phone and radio, lower the windows, put on the four-way flashers and sound the horn. It then tells you to get out and walk around the area you will back into, checking for overhead wires, side clearances and pedestrians, and to use both mirrors. Notifying an operator beforehand appears nowhere in that routine, so it is the item that does not belong with the others.
Official handbook: Official MTO Truck Handbook, Backing
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Last checked: 2026-10-17 · Verified from official source

Updated: · Based on the official driver handbook