1. Under the federal Hours of Service regulations, what is the maximum daily driving time permitted for a commercial driver who is not using a sleeper berth?
- A. 10 hours
- B. 11 hours
- C. 12 hours
- D. 13 hours ✓
Under Canada's federal Hours of Service regulations, a driver may drive a maximum of 13 hours in any day (defined as a 24-hour period). This is distinct from on-duty time, which is capped at 14 hours per day. The 13-hour driving limit applies whether or not a sleeper berth is used.
2. What is the purpose of the air dryer in an air brake system?
- A. To cool compressed air before it reaches the brake chambers
- B. To remove moisture and contaminants from compressed air before it enters the reservoirs ✓
- C. To reduce air pressure to the service brake chambers
- D. To automatically drain the wet tank every 24 hours
The air dryer removes moisture and oil from compressed air before it enters the reservoirs. This prevents moisture from freezing in lines and valves in cold weather and protects system components from corrosion and contamination.
3. When performing the fifth-wheel inspection during a pre-trip, the driver should verify that the fifth-wheel locking jaws are:
- A. Partially open to allow minor kingpin movement and reduce coupling stress
- B. Fully closed and locked around the kingpin shank with no gap visible ✓
- C. Greased and open so the kingpin can self-seat during initial movement
- D. Positioned so the kingpin rests on the lip of the fifth-wheel plate for easy release
The locking jaws of the fifth wheel must be fully closed around the kingpin shank with no visible gap, and the release handle must be in the locked position. Any gap or partial engagement indicates an improper coupling that could result in trailer separation, which is a critical safety defect.
4. In Canada, what is the mandatory minimum off-duty time a driver must take before driving after reaching the end of their daily 14-hour on-duty window?
- A. 6 consecutive hours of off-duty time.
- B. 8 consecutive hours of off-duty time. ✓
- C. 10 hours of off-duty time, which may be split under sleeper berth provisions.
- D. 12 consecutive hours of off-duty time.
Under Canadian federal hours-of-service rules, after a driver reaches the work-shift limit such as 14 hours on duty, they may not drive again until they have taken at least 8 consecutive hours of off-duty time, which starts a new work shift. The separate daily rule requires 10 total hours off duty in a day, but that is not the same as the minimum consecutive off-duty period needed before driving again after the 14-hour on-duty limit.
5. A driver notices the low air pressure warning activates at approximately 380 kPa (55 psi). What should the driver do FIRST?
- A. Continue driving but avoid hard braking
- B. Immediately downshift to slow the vehicle using engine braking
- C. Safely bring the vehicle to a stop and apply the parking brakes ✓
- D. Pump the brake pedal rapidly to build pressure
When the low air pressure warning activates, the driver must safely stop the vehicle immediately and apply the parking brakes. At low pressure, the spring brakes may apply automatically; pumping the brakes will deplete remaining pressure faster and is dangerous.
6. What is the primary purpose of the trailer supply (emergency) air line (typically red-coded) in a tractor-trailer air brake system?
- A. To apply the trailer service brakes during normal stops
- B. To supply air to the trailer air tanks and control the trailer spring parking brakes ✓
- C. To regulate air pressure to the ABS modulator valves on the trailer axles
- D. To provide a backup air source to the tractor brake system if the tractor tank fails
The red-coded trailer supply (emergency) line carries air from the tractor to charge the trailer's air reservoirs and hold the trailer spring parking brakes in the released position. If this line loses pressure — due to separation or a major leak — the trailer spring brakes automatically apply as a fail-safe.
7. Under Canada's NSC Standard 10 cargo securement rules, the aggregate working load limit (WLL) of all tiedowns must be at least what fraction of the total weight of the cargo being secured?
- A. One-quarter (25%) of the cargo weight.
- B. One-half (50%) of the cargo weight. ✓
- C. Three-quarters (75%) of the cargo weight.
- D. Equal to (100%) the full weight of the cargo.
NSC Standard 10 requires that the aggregate working load limit of all tiedowns used to secure an article of cargo must be at least 50% (one-half) of the weight of that cargo. This ensures adequate restraint against forward, rearward, and lateral movement during transport.
8. What is the function of the automatic slack adjuster on an air brake system?
- A. It limits maximum air pressure to the brake chambers
- B. It maintains the correct clearance between the brake lining and drum as linings wear ✓
- C. It prevents air from entering the spring brake chamber
- D. It controls the rate at which air is exhausted during brake release
Automatic slack adjusters maintain the proper pushrod stroke and lining-to-drum clearance as brake linings wear over time. They compensate for wear automatically, but must still be inspected because they can malfunction and produce excessive pushrod stroke.
9. What is 'jackknifing' in a tractor-trailer, and which axle group losing traction is MOST commonly responsible?
- A. The trailer overriding the tractor; caused by loss of traction on the trailer axles
- B. The tractor cab folding toward the trailer; caused by loss of traction on the tractor drive axles ✓
- C. The front axle skidding; caused by overloading of the steer axle
- D. The trailer axles locking; caused by underinflated trailer tires
A jackknife occurs when the tractor folds at the fifth-wheel pivot point toward the trailer. It is most commonly caused by the tractor's drive axles losing traction and skidding — typically from excessive braking or deceleration — while the trailer's momentum continues to push the tractor's rear sideways.
10. Under Ontario's Highway Traffic Act, commercial motor vehicles with a registered gross weight exceeding 11,794 kg must have a speed limiter set to a maximum of what speed?
- A. 100 km/h
- B. 105 km/h ✓
- C. 110 km/h
- D. 115 km/h
Ontario requires applicable large commercial motor vehicles operating in the province, generally those over 11,794 kg, to have a functioning speed-limiting system set so the vehicle cannot exceed 105 km/h. This applies to both Ontario and out-of-province vehicles when operating in Ontario, subject to the regulation’s specific exemptions.