Low Air Pressure Indicator & Service Brake Pressure Gauge (Chapter 4) +13Quebec · CDL · English

If air pressure drops too low in a circuit for the service brakes to work effectively, a visual warning (warning light or wigwag), sometimes with a buzzer, alerts the driver. The activation level varies but is never lower than 380 kPa (55 psi).

• ✓Two types of visual warning: warning light and wigwag
• ✓Sometimes accompanied by a buzzer
• ✓Never activated lower than 380 kPa (55 psi)
• ✓At 380 kPa there is too little pressure to release the parking brake but enough to keep moving

This gauge measures the compressed air pressure in the brake chambers when the brakes are applied. Unlike the air pressure gauge, it is not a standard feature on heavy vehicles.

• ✓Measures air pressure in the brake chambers when brakes are applied
• ✓Not a standard feature on heavy vehicles

Liquids change volume with temperature and vary in density, affecting weight limits, so tanks must not be overfilled.

• ✓Account for the liquid's density and temperature when filling to comply with the manufacturer's maximum load on the certification plate
• ✓Some liquids (e.g. sulfuric acid) are denser than water and may cause the vehicle to exceed weight limits
• ✓Never fill a tank to more than 70% of its capacity

Liquid movement in a tank creates thrust forces during braking and turns; baffles reduce forward/backward surge but not side-to-side movement.

• ✓When braking, liquid forms a wave that strikes the front then rebounds rearward, exerting thrust in that direction
• ✓Baffles stabilize forward/rearward liquid movement but side-to-side displacement still occurs and can overturn the vehicle
• ✓Reduce speed well below the maximum limit, especially in slippery conditions and on curves, exits and turns

Livestock must be restrained to prevent rollover risk, and dry bulk tank trucks require smooth driving due to their high centre of gravity.

• ✓Livestock must be restrained or in cages to avoid any risk of the vehicle overturning
• ✓For dry bulk in tank trucks, avoid sudden steering or braking when negotiating curves or turning at intersections due to high centre of gravity

Liquid must be distributed evenly across compartments for safe loading, unloading and handling.

• ✓In multi-compartment tanks, distribute the liquid evenly in each compartment
• ✓Avoid placing too much weight at the front or rear of the tank when loading and unloading

Livestock must be restrained or caged to prevent the vehicle from overturning. Tank trucks carrying dry bulk have a high centre of gravity requiring smooth driving.

• ✓Livestock must be restrained or in cages to avoid the risk of overturning
• ✓With dry bulk tank trucks, avoid sudden steering or braking in curves and at intersections due to high centre of gravity

When an LCV exceeds the total loaded mass and length prescribed by the Vehicle Load and Size Limits Regulation, the operator or owner must obtain a special operating permit issued by the Ministère des Transports du Québec. The original permit and appendices must be carried at all times when operating on the road network.

• ✓A special operating permit is required when an LCV exceeds prescribed mass and length limits
• ✓The permit is issued by the Ministère des Transports du Québec
• ✓You must carry the original permit papers and appendices at all times when operating

A special road train operating permit is valid for a maximum of twelve consecutive months.

• ✓A special road train operating permit is valid for a maximum of twelve consecutive months

Certain vehicles by weight rating, type, or cargo must undergo a circle check to keep their road authorization.

• ✓Road vehicles with a GVWR of 4,500 kg or more require a circle check
• ✓Combinations where at least one vehicle has a GVWR of 4,500 kg or more require inspection of all vehicles in the combination
• ✓Buses, minibuses and tow trucks require a check regardless of GVWR
• ✓Vehicles under 4,500 kg GVWR transporting dangerous substances requiring safety marks must undergo a check

Specific categories of vehicles, mainly tool, farm, emergency, and personal-use vehicles, are exempt from the circle check requirement.

• ✓Tool vehicles (grader, wheel loader, back hoe) are exempt
• ✓Heavy vehicles used for emergency service or disasters, farm tractors, farm machinery and farm trailers are exempt
• ✓Heavy vehicles used by an individual for personal, non-commercial purposes are exempt
• ✓Two/three-axle straight-body trucks transporting unprocessed farm/forest/fishery products (driver is also the producer), or empty on return trip, are exempt

Check the working order of the low beams. Switch them on in the driver's compartment and check the front right and front left from outside, ensuring high beams are not activated.

• ✓Defect 8.A (major): None of the low beams work
• ✓Defect 8.1 (minor): One of the low beams does not work

Check parking (front) and tail (rear) lights. Front parking lights are only mandatory on vehicles 2.03 m wide or less. Switch on and check front right, front left, rear right, rear left for each vehicle in the combination. A compliant vehicle has one right and one left rear tail light (plus front parking lights if width ≤ 2.03 m).

• ✓Defect 8.B (major): None of the rear parking lights work for a single-unit vehicle or the last vehicle in a combination
• ✓Defect 8.1 (minor): One rear light out on a single-unit vehicle; or when hitched one/both rear parking lights out on tractor or first semi-trailer of a double road train, or one out on the last vehicle; or one/both front parking lights out
• ✓Front parking lights are only mandatory on vehicles 2.03 m wide or less

Check front and rear turn signals. Switch on one side then the other and check front right, front left, rear right, rear left for each vehicle. A compliant vehicle has front and rear turn signals on both right and left.

• ✓Defect 8.B (major): On a single-unit or last vehicle, none of the rear right or none of the rear left turn signals work
• ✓Defect 8.1 (minor): One/both front turn signals out; when hitched one/both rear signals on tractor or first semi-trailer of a double road train out; on single-unit or last vehicle with GVWR < 4,500 kg one/both turn signals out

Check brake lights working order safely — use a second person or reflections. Press the brake pedal and confirm lights switch on. A compliant vehicle has one rear left and one rear right brake light. For vehicles with two or more brake lights per side, no defect if at least one per side works.

• ✓Defect 8.B (major): None of the brake lights switch on for a single-unit vehicle or the last vehicle of a combination
• ✓Defect 8.1 (minor): One brake light out on single-unit; or when hitched one/both out on tractor or first semi-trailer of a double road train, or one out on last vehicle
• ✓For two or more brake lights per side, no defect if at least one on each side switches on

Switch turn signals on each side and check front right/left and rear right/left. A compliant vehicle has front right/left and rear right/left turn signal lights.

• ✓Major defect (8.B): none of the rear right or rear left turn signals work on a single-unit or last vehicle of a combination
• ✓Minor defect (8.1): one/both front turn signals out; when hitched, rear turn signal(s) out on tractor/first semi-trailer; or on a single-unit/last vehicle with GVWR under 4,500 kg, one/both turn signals out

Requirements concerning lights apply at all times, not only at night. Heavy vehicle lighting and signalling devices include: high/low beams, parking/tail/side marker lights, turn signal lights, brake lights, licence plate light, clearance lights, and identification lights.

• ✓Light requirements must be considered at all times, not only at night
• ✓Devices include high/low beams, parking/tail/marker, turn signals, brake lights, licence plate light, clearance lights, and identification lights

Check the working order of the light illuminating the licence plate from outside at the rear. A compliant vehicle has a white light positioned to illuminate the rear licence plate. School buses also require checking alternately flashing stop-sign lights, flashing red lights, and alternately flashing yellow warning lights.

• ✓Defect 8.1 (minor): The rear licence plate light is not working
• ✓School buses require additional checks of stop-sign flashers, flashing red lights, and yellow warning lights (sections 20.7, 20.8, 20.9)

Under the Highway Safety Code, if involved in an accident you must remain at or return to the scene immediately, help any injured victim, contact the police, and provide any information required by the police officer at the scene.

• ✓Remain at or return to the accident scene immediately
• ✓Help injured victims and contact the police
• ✓Provide required information to the police officer at the scene

If first to arrive or a witness, park about 30 m from the scene and turn on emergency lights, contact police immediately, turn off the ignition of the involved vehicle if anyone is injured, and set out flares or reflectors to warn others. A first-aid course and a first-aid kit are recommended.

• ✓Park about 30 m from the accident scene with emergency lights on
• ✓Turn off the ignition of the involved vehicle if anyone is injured
• ✓Ensure you can provide assistance without endangering yourself or others

The brake pedal activates the service brakes on all wheels including the trailer/semi-trailer. Pressing it lets compressed air flow from the service reservoirs into the brake chambers; more pedal pressure means more air. Required pressure varies by vehicle and load.

• ✓Brake pedal activates service brakes on ALL wheels including trailer
• ✓More pedal pressure sends more air to brake chambers
• ✓Required pressure varies by vehicle and load

The hand brake control applies service brakes ONLY on the semi-trailer's wheels. It can check whether the semi-trailer is properly hitched and whether trailer service brakes work. It must NEVER be used as a parking brake or as a service brake on the road.

• ✓Hand brake applies service brakes only to the semi-trailer wheels
• ✓Never use it as a parking brake
• ✓Never use it as a service brake on the road

The parking brake control is a yellow diamond-shaped knob on the dashboard. Pull up to release air from brake chambers, activating springs that clamp the wheels. It holds tractor and semi-trailer stationary. Push down before driving to release the parking brakes by filling chambers with air.

• ✓Parking brake control is a yellow diamond-shaped knob
• ✓Pull up to apply (releases air, springs clamp wheels)
• ✓Push down to release parking brakes before driving
• ✓Must pull up before getting out of the cab

The trailer air supply control is an octagonal red knob on the dashboard, always the same colour and shape in all vehicles. Push down to send air to trailer/semi-trailer reservoirs and release the trailer parking brake. Pull up to close the valve, exhaust air, and apply the trailer parking brake — used to immobilize a trailer before unhitching.

• ✓Trailer air supply control is an octagonal RED knob
• ✓Push down to supply air to the trailer/semi-trailer
• ✓Pull up to apply the trailer parking brake and immobilize before unhitching
• ✓Colour and shape are standard in all vehicles

Using the hand brake as a service brake on the road is less effective than the brake pedal, distributes braking unequally, overheats semi-trailer brakes reducing effectiveness, and can cause skidding on icy surfaces.

• ✓Less effective than the service brake pedal
• ✓Causes unequal braking and semi-trailer brake overheating
• ✓Can cause skidding on ice

A Class 1 licence authorizes driving combinations of vehicles: double-axle road tractors (net weight 4,500 kg or more) hauling trailers/semi-trailers; triple-axle road tractors hauling trailers/semi-trailers; and Class 3 trucks hauling specified trailers/semi-trailers. A road tractor has no cargo space and is permanently equipped with a fifth wheel.

• ✓Class 1 permits a double-axle road tractor (4,500 kg+ net) hauling one or more trailers/semi-trailers
• ✓Class 1 permits a triple-axle road tractor hauling one or more trailers/semi-trailers
• ✓Class 1 permits Class 3 trucks hauling trailers/semi-trailers of 4,500 kg+ (equipment) or 2,000 kg+ (other)
• ✓A road tractor has no cargo space and is permanently equipped with a fifth wheel
• ✓Class 1 holders may drive all other vehicle categories except motorcycles

Passing uses the same checks as changing lanes and means changing lanes twice — into the left lane then back into the right. Turn off signals after each lane change. A heavy vehicle needs greater distance to pass because it is longer and heavier than a car. Ensure other road users understand your intentions.

• ✓Passing is two lane changes; turn off the signal after each
• ✓Allow greater distance to pass because a heavy vehicle is longer/heavier
• ✓Avoid using the horn unless necessary; at night flick high-to-low beams to signal presence

Do not signal other drivers when to pass — there may be people or vehicles you cannot see, and a driver relying on your signal may become overconfident and less alert. Concentrate on signalling only your own intentions.

• ✓Never signal other road users when to pass
• ✓Signal only your own intentions

Passing uses the same checks as changing lanes and means changing lanes twice—into the left lane then back to the right. Turn off signals after each lane change. You need a greater distance to pass because your vehicle is longer and heavier than a car.

• ✓Passing is changing lanes twice—left then back to the right
• ✓Turn off turn signals after each lane change
• ✓Allow greater distance to pass because heavy vehicles are longer and heavier
• ✓Avoid using the horn when passing unless absolutely necessary
• ✓At night, flick between high and low beams to signal your presence before passing

Do not signal other road users when to pass. You may not see all people or vehicles, and drivers who pass on your signal may become overconfident and less alert. Concentrate only on signalling your own intentions.

• ✓Never signal other road users when to pass
• ✓You may not see all hazards that would make passing unsafe
• ✓Concentrate on signalling your own intentions only

For a combination with more than one trailer, repeat the same inspection on the second trailer as on the first. For straight-body trucks (or hauling a trailer), the method is similar but adapt to the braking system and whether a trailer is hitched. A straight-body truck alone has one coupling system (1.C, 1.F, 1.1, 1.2) and only one parking brake to check (18.5, 19.5). When hitched to a trailer, the coupling system is different and located completely at the rear of the truck.

• ✓Repeat the same inspection on each trailer of a multi-trailer combination
• ✓A straight-body truck alone has only one parking brake to check (18.5, 19.5)
• ✓When a straight-body truck hauls a trailer, the coupling system is at the rear of the truck

Buses and motor coaches require additional passenger-safety checks: central aisle lighting, solidity of stanchions and luggage racks/compartments, condition of protective material, and accessibility of emergency exits (section 20). For city buses, the engine compartment is usually at the rear; some start there after the initial approach, then circle from front or rear. Additional city bus elements include emergency exit and door warning device (10.B, 10.C), emergency material (7.1, 7.2), stanchions and shock-absorbing material (20.1, 20.2), floors and steps (20.3), interior lighting (20.4), luggage compartments (20.5) and seats/benches (20.6).

• ✓Buses require additional checks of aisle lighting, stanchions/racks, protective material and emergency exit accessibility
• ✓City bus additional checks include the emergency exit and emergency door warning device (10.B, 10.C)
• ✓Adapt the circle check to the bus layout and the type of transportation it provides

For a combination with more than one trailer, repeat the same inspection on each additional trailer. For straight-body trucks, the circle check is similar but adapted to the braking system and whether a trailer is hitched. A straight-body truck alone has only one coupling system and one parking brake to check. A straight-body truck hitched to a trailer has a different coupling system located completely at the rear.

• ✓Repeat the trailer inspection for each additional trailer in a multi-trailer combination
• ✓A straight-body truck alone has only one parking brake to check (18.5, 19.5)
• ✓A straight-body truck hitched to a trailer has a different coupling system located at the rear (1.C, 1.F, 1.1, 1.2)

List 2 applies to buses (other than motor coaches), minibuses, and any trailer towed by a bus/minibus/motor coach. Bus-specific major door defects include an emergency exit blocked and an inadequate emergency door or its warning light/buzzer not working.

• ✓List 2 applies to buses (not motor coaches), minibuses, and trailers towed by them
• ✓Major (10.B): emergency exit blocked; Major (10.C): emergency door inadequate or its warning light/buzzer not working

For buses, a specific glass defect (11.4) applies to school buses: a side window on each side of and immediately behind the driver's compartment that fails to provide the required view due to damage is a minor defect.

• ✓Minor (11.4): school bus side windows beside and immediately behind the driver's compartment failing to provide required view due to damage
• ✓This is in addition to standard windshield/side window and mirror defects (11.1–11.3)

Passenger transport defects for buses are all minor and include insecure stanchions/grab handles, missing shock-absorbing material, damaged floors/steps, inoperative aisle lighting, insecure luggage racks, inadequate seats, and stop sign or flashing light failures.

• ✓Minor (20.7): stop sign not operating properly or one flashing light not turning on
• ✓Minor (20.8): one flashing light or one alternately flashing yellow light not turning on
• ✓Minor: insecure stanchions/grab handles/guard panels, missing shock-absorbing material, damaged floor/steps, inoperative access/aisle lighting, insecure luggage racks, inadequate seats

To avoid fire, take preventive measures before a trip and at each stop (see circle checks in Chapter 12). Continuously check temperature readings and use rearview mirrors to check for smoke coming from the rear of the vehicle.

• ✓Perform circle checks before and during trips to prevent fires
• ✓Continuously monitor temperature readings
• ✓Use rearview mirrors to check for smoke from the rear

If fire breaks out, pull off the road away from buildings and vehicles, switch off the engine, and move away if there is an explosion risk. Stop traffic, direct people away, and call for assistance. Then, if possible, unhitch the semi-trailer and move the tractor, switch off the engine, and use a fire extinguisher. If the fire is in the engine compartment, raise the hood. Never use water on a fuel-fed fire; keep your back to the wind when using an extinguisher.

• ✓Pull off away from buildings/vehicles, switch off engine, move away if explosion risk
• ✓Call for assistance and direct people away from the vehicle
• ✓Unhitch the semi-trailer and move the tractor away if possible
• ✓Do NOT use water on a fuel-fed fire; keep your back to the wind with an extinguisher

Take preventive measures through circle checks before and during a trip. Continuously check temperature readings and use rearview mirrors to check for smoke from the rear of the vehicle.

• ✓Perform circle checks to prevent fires
• ✓Continuously check temperature readings and watch mirrors for smoke from the rear

When multiple drivers use a vehicle within 24 hours, each must perform or accept a valid circle check.

• ✓Each driver must perform a circle check before getting behind the wheel within a 24-hour period
• ✓If operator designated a person, each subsequent driver may accept (co-sign) or refuse it
• ✓A driver refusing must perform a new circle check and fill out another report
• ✓A driver regaining control within 24 hours of their own check needs no new report, but the initial report must be on board and accurately reflect the vehicle's condition

For these specific vehicles, successive drivers can accept and co-sign a check even if it was not done by a designated person.

• ✓Successive drivers can accept and co-sign the circle check report even if not performed by a designated person
• ✓The co-signing driver assumes responsibility and must keep the report updated
• ✓If the driver refuses, they must perform a new circle check

For team-driven vehicles, recommended procedures cover each driver performing checks, with reports valid for 24 hours.

• ✓First driver carries out the circle check and fills out a report; relief driver does another when taking the wheel
• ✓Both reports remain valid for a period of 24 hours
• ✓If the operator designates one driver, the other may co-sign (accept) or perform a new check (refuse)

For team-driven motor coaches, the relief driver may co-sign the first driver's report even if the first driver was not designated by the operator.

• ✓Relief driver may co-sign the first driver's report if accepted, even if first driver was not designated by operator
• ✓The co-signing driver is accountable for the check and must keep it updated and report defects

Night driving is difficult and demanding, contributing to fatigue. It is strongly recommended to drive more slowly than the speed limit at night so your stopping distance stays within your headlight range.

• ✓The faster you drive, the narrower your field of vision, increasing perception and reaction time for hazards
• ✓Make sure your stopping distance is within the range of your headlights
• ✓Low beams light up to about 75 m ahead and high beams up to about 150 m ahead

Night driving reduces visual acuity, contrast perception, colour discrimination and depth perception, making distance and speed hard to evaluate.

• ✓Reduce speed to compensate for reduced night vision
• ✓Look beyond the area covered by headlights to detect pedestrians or obstacles with enough time to react
• ✓Never wear tinted glasses at night because they reduce visibility

Glare from lights can impair vision for several seconds, during which you can cover a fair distance before your eyes readjust to the dark.

• ✓Limit and lower dashboard light sources and avoid looking directly at other vehicles' headlights; look toward the right side of the road
• ✓If blinded by oncoming headlight glare, slow down until your eyes readjust to the dark
• ✓Flip back to high beams immediately after passing an oncoming vehicle; if another driver won't dim their high beams, do not insist—slow down, stay right, look right, and pull over if needed

Even fine weather can be dangerous due to a false sense of security. Blinding sunlight is a major hazard. When it begins to rain, the road surface becomes slippery as water mixes with dust, sand and oil.

• ✓Slow down when it begins to rain so you do not have to steer or brake abruptly on slippery pavement
• ✓At dawn, dusk, rain, snow or fog, turn on your headlights so you are visible to others
• ✓Parking and tail lights alone are not sufficient for others to see you clearly

When roads are snow-covered, slippery or visibility is reduced, braking and steering are much more difficult. Loss of traction affects acceleration, braking and handling.

• ✓If visibility is reduced by snow or freezing rain, use wipers and pull over to clean windshield, windows and mirrors
• ✓If visibility is nil, pull over somewhere safe as soon as possible
• ✓Slow down in winter conditions due to less traction; be especially careful when braking since cars following behind may not be visible to you

Road surfaces on bridges and overpasses can become especially slippery and dangerous when temperatures fall near freezing due to condensation forming an invisible sheet of black ice.

• ✓Bridges and overpasses freeze before other road surfaces near the freezing point
• ✓An invisible sheet of 'black ice' may form on the roadway due to condensation

Night driving is difficult and demanding and contributes to fatigue. It is strongly recommended to drive slower than the speed limit at night because the faster you drive the narrower your field of vision. Make sure your stopping distance stays within the range of your headlights.

• ✓Drive more slowly than the speed limit at night for safety
• ✓With low beams you can see about 75 m ahead; with high beams about 150 m ahead
• ✓Make sure your stopping distance is within the range of your headlights
• ✓The faster you drive the narrower your field of vision

Driving can be dangerous even in fine weather due to false security and blinding sunlight. When rain first mixes with road dust, sand and oil, pavement becomes slippery. At dawn, dusk, or in rain/snow/fog it is hard to see and be seen—turn on headlights.

• ✓Blinding sunlight can become a major hazard even in fine weather
• ✓When it begins to rain, water mixing with dust, sand and oil makes pavement slippery—slow down to avoid abrupt steering or braking
• ✓Turn on your headlights at dawn, dusk and in rain, snow or fog to be visible
• ✓Parking and tail lights are not sufficient for others to see you clearly

If snow or freezing rain reduces vision, use wipers and pull over to clean the windshield, windows, mirrors and clear ice/snow off wipers. On snow-covered or slippery roads braking and steering are much harder—slow down. If visibility is nil, pull over safely. Winter poses icy patches and black ice with less traction.

• ✓If visibility is reduced, use wipers and pull over to clean windshield, windows and mirrors
• ✓On snow-covered or slippery roads, braking and steering are much more difficult—slow down
• ✓If visibility is nil, pull over somewhere safe as soon as possible
• ✓Loss of traction affects your vehicle's acceleration, braking and handling

Road surfaces on bridges and overpasses can become especially slippery and dangerous when temperatures fall near freezing. Because of condensation, an invisible sheet of ice called 'black ice' may form on the roadway.

• ✓Bridges and overpasses become especially slippery when temperatures fall near the freezing point
• ✓Condensation can form an invisible sheet of 'black ice' on the roadway
• ✓Exercise extra caution and slow down on bridges and overpasses in near-freezing conditions

At night, being seen by others is as important as being able to see. Clean lights, mirrors and windshield keep your field of vision unrestricted and minimize negative light effects.

• ✓Make sure your vehicle's lights are clean and in good working order
• ✓Keep mirrors and windshield clean inside and out, especially in bad weather

Night driving reduces visual acuity, ability to make out contrasts, discriminate colours and perceive depth. Objects blend with darkness, making distance and speed hard to judge. Reduce speed and look beyond your headlights to detect pedestrians or obstacles in time.

• ✓Night driving reduces visual acuity, contrast perception, colour discrimination and depth perception
• ✓Reduce your speed to compensate for reduced visibility at night
• ✓Look beyond the area covered by your headlights to detect pedestrians or obstacles with enough time to react

Glare from lights can impair vision for several seconds, during which you cover distance before your eyes readjust. Never wear even slightly tinted glasses at night. Specific techniques help manage glare from oncoming and following vehicles.

• ✓Never wear glasses that are even slightly tinted at night because they reduce visibility
• ✓Avoid looking directly at other vehicles' headlights; look toward the right side of the road
• ✓If blinded by oncoming glare, slow down and let your eyes readjust before resuming speed
• ✓If other drivers keep high beams on, click yours on and off once; if they don't dim, slow down and look to the right, pulling over if needed

At night, being seen is as important as being able to see. Keep vehicle lights clean and in good working order. Keep mirrors and windshield clean inside and out for unrestricted vision and minimal glare effects, especially in bad weather.

• ✓At night, being seen by others is just as important as being able to see
• ✓Make sure your vehicle's lights are clean and in good working order
• ✓Keep mirrors and windshield clean inside and out, especially important in bad weather

Car drivers sometimes follow too closely behind heavy vehicles and are usually unaware that the heavy vehicle driver cannot see them. Be especially careful when braking.

• ✓Car drivers often follow too closely and are not aware the heavy vehicle driver cannot see them
• ✓Be especially careful when braking to protect vehicles following behind you