Ontario Class C Driver's Licence (Commercial) key terms

The Ontario regulation setting out driving prohibitions, demerit points and licence suspensions for offences such as careless driving, speeding and failing to remain at a collision.

Penalty points added to a driver's record when convicted of certain offences. Accumulating too many within a two-year period triggers warning letters and licence suspensions.

A temporary loss of driving privileges ordered by the Ministry or a court. A suspended driver must not operate any vehicle until the suspension is formally lifted.

Operating a vehicle without due care and attention, or without reasonable consideration for other road users. It carries substantial demerit points and possible licence suspension.

Driving behind another vehicle at a distance that does not allow a safe stop if it slows suddenly. Following distance should increase with speed and poor conditions.

The buffer of clear space kept around a bus so the driver has time and room to react. It includes following distance, lane position and gaps beside and behind.

The gap between your bus and the vehicle ahead, measured in seconds of travel time. A minimum of four seconds is commonly taught for large commercial vehicles.

The total distance needed to bring the bus to a complete stop, made up of perception distance, reaction distance and braking distance, and increased by weight and speed.

The distance travelled from the moment the brakes are applied until the vehicle stops. It grows with speed, load and slippery surfaces, and is longer with air brakes.

The short delay between pressing the brake pedal and the brakes actually applying, caused by the time air takes to travel through the lines to the brake chambers.

The component at each wheel that converts air pressure into mechanical force to apply the service brake. It contains a diaphragm and a pushrod.

The linkage between the brake chamber pushrod and the brake shoe that transfers and adjusts braking force. Excessive pushrod travel means the brakes need adjustment.

The maximum permitted pushrod travel for a brake chamber before the brake is considered out of adjustment and the vehicle must be taken out of service.

The rate at which the compressor raises air pressure in the system. A slow buildup suggests a compressor, governor or leak problem that must be repaired.

A check for air loss with the system charged and the engine off. Pressure should not drop beyond the permitted rate; a larger drop indicates a leak.

A buzzer and light that activate when system pressure falls to an unsafe level, warning the driver to stop safely before the spring brakes apply automatically.

A parking and emergency brake held off by air pressure and applied by a strong spring when air is released. It engages automatically during a major air loss.

A check that the spring or parking brakes hold the vehicle stationary, often performed by applying the brake and attempting to move against it at low speed.

A valve that controls the compressor, cutting it in at a low pressure and out at a high pressure to keep system air within the proper operating range.

A device that removes moisture from compressed air before it reaches the reservoirs, helping prevent corrosion and freeze-ups in the brake system.

A valve at the bottom of an air reservoir used to release accumulated moisture and contaminants. Reservoirs should be drained as part of the daily inspection.

A systematic check of the vehicle before driving, covering brakes, lights, tires, steering, mirrors, emergency equipment and cargo, to confirm it is safe to operate.

The required inspection of a commercial vehicle each day it is used, documented in a report and signed by the driver, with defects reported to the operator.

A written record listing any defect found during inspection or operation. Major defects must be reported and repaired before the vehicle is driven again.

A status applied when a vehicle or driver fails a safety standard or hours rule and may not continue until the problem is corrected or the required rest is taken.

A structured circuit around the bus checking tires, wheels, lights, body panels, emergency exits and fluid leaks before and after a trip.

The thickness of remaining rubber above the tread wear indicators. Worn tires reduce traction and are a common out-of-service item on commercial vehicles.

Rules limiting driving and on-duty time and requiring rest periods, designed to prevent fatigue. They include daily and cycle limits plus mandatory off-duty time.

A record of a driver's duty status over a 24-hour period, showing driving, on-duty and off-duty time, which must be carried and produced on request.

The maximum on-duty time permitted over a defined multi-day cycle, such as 70 hours in seven days, after which a reset or reduced cycle is required.

Time when the driver is relieved of all duties and free to rest. Sufficient consecutive off-duty hours are required before a new driving day begins.

The methods and devices used to prevent cargo from shifting, tipping or falling. Loads must be tied down to standards that vary with weight and type.

A strap, chain or other device that anchors cargo to the vehicle. The number and strength required depend on the weight and length of the load.

The maximum load a tie-down or securement component is rated to hold safely. The combined rating of all devices must meet or exceed the cargo weight requirement.

The maximum weight a vehicle, axle or tire may legally carry. Exceeding it affects handling, braking and compliance with weight regulations.

The portion of total vehicle and cargo weight carried by a single axle or axle group. Each has a legal maximum that must not be exceeded.

The manufacturer's maximum safe total weight for the vehicle including chassis, body, passengers, fuel and cargo. It must never be exceeded in operation.

A shipping document describing the goods, their quantity and destination. Drivers should confirm it matches the load before departure and keep it available.

A door, window or roof hatch designed for rapid evacuation. It must be clearly marked, unobstructed and operational, and checked during inspection.

The stop sign extended from a school bus when loading or unloading students. Traffic in both directions must stop unless separated by a median.

Alternating amber and red lights used to warn traffic. Amber means the bus is preparing to stop; red means stop and do not proceed until withdrawn.