Driving a Double Road Train +10Quebec · CDL · English

If you have mastered tractor semi-trailer techniques, you have the base skills, but double road trains react differently in weather. They may spin wheels on slippery pavement and are more likely to skid on level roads, grades, snow, or wet pavement. Know how it handles to react to unexpected hazards.

• ✓A double road train is more likely to have wheels spin in place on slippery pavement
• ✓It is more likely to skid on level roads, grades, snow, or wet pavement than other heavy vehicles
• ✓Always drive safely and defensively to anticipate and avoid hazards

Defensive driving involves obeying speed limits and signals, paying constant attention, performing manoeuvres smoothly, looking far ahead, applying brakes gradually to prevent lockup and jackknifing, planning routes, watching for fatigue, and checking mirrors for weaving.

• ✓Obey speed limits, road signs and traffic signals and perform manoeuvres smoothly
• ✓Look far ahead to anticipate problems and avoid frequent braking or abrupt changes
• ✓Apply brakes gradually to prevent wheel lockup and minimize jackknifing risk
• ✓Check rearview mirrors regularly to ensure the second semi-trailer is not weaving

Jackknifing is a type of accident that occurs when the angle of lateral rotation between a fifth-wheel tractor and a semi-trailer exceeds 90°. Applying brakes gradually helps minimize this risk.

• ✓Jackknifing occurs when the angle of lateral rotation between tractor and semi-trailer exceeds 90°
• ✓Apply brakes gradually to prevent wheel lockup and minimize the risk of jackknifing

Bumpy roads, high winds, or abrupt steering can cause the second semi-trailer to weave back and forth, called fishtailing. When changing lanes, the second semi-trailer may swing widely and can gradually increase until it overturns. Fishtailing may be hard to detect, reducing reaction time.

• ✓Fishtailing is the second semi-trailer weaving back and forth, caused by bumps, wind or abrupt steering
• ✓Fishtailing can gradually increase to the point where the second semi-trailer overturns
• ✓Stay focused on the road and check rearview mirrors regularly to detect and control fishtailing

In theory a double road train has greater braking capacity due to more wheels, but in practice more axles and articulations make it harder to brake evenly (stopping tractor and trailers at the same time with same power). Avoid braking abruptly or applying brakes for extended periods.

• ✓More axles and articulations make it harder to brake evenly across the combination
• ✓Avoid braking abruptly or applying brakes over an extended length of time
• ✓Constantly monitor traffic and adjust speed to avoid frequent braking
• ✓Leave enough space between you and the vehicle in front

To determine safe following interval, divide vehicle length in metres by three and count one second for every three metres. A 24 m double road train needs an 8-second interval (24 / 3 = 8). Use a stationary roadside reference point and count seconds as the lead vehicle passes it.

• ✓Divide the vehicle length in metres by three to get the following interval in seconds
• ✓A 24 m double road train requires an 8-second following interval (24/3=8)
• ✓If you reach the reference point before finishing the count, you are following too closely

When forced to brake abruptly, avoid wheel lockup by keeping brakes in good order and load properly distributed. Front tractor wheels locking prevents steering; back tractor wheels locking can cause jackknifing; second semi-trailer wheels locking can cause fishtailing.

• ✓If the front wheels of the tractor lock up, you cannot steer properly
• ✓If the back wheels of the tractor lock up, the vehicle could jackknife
• ✓If the wheels of the second semi-trailer lock up, it may begin fishtailing
• ✓Keep the brake system in good order and load properly distributed to avoid lockup

When turning or negotiating a curve, evaluate space needed and account for the rear axles of the second semi-trailer crossing into the other lane. How far they cross depends on total length and fifth wheel/axle adjustment. B trains turn easier (shorter wheelbase); A trains have three pivot axes and are harder to turn.

• ✓The rear axles of the second semi-trailer tend to cross into the other lane when turning
• ✓A B train is easier to turn because it usually has a shorter wheelbase
• ✓An A train has three pivot axes, a longer wheelbase, and is harder to turn
• ✓Coordinate speed and direction to steer the vehicle exactly where you want it

Right turns are the hardest manoeuvre due to collision risk in the adjacent lane. Keep the vehicle in the right lane, prevent road users entering the space, hold the front end close to the dividing line, keep rear wheels off the sidewalk/shoulder, then steer back to lane centre.

• ✓Right turns are the hardest manoeuvre due to collision risk with adjacent-lane vehicles
• ✓Keep the vehicle in the right lane and prevent other road users from entering the space
• ✓Hold the front end close to the dividing line and keep rear wheels off the sidewalk or shoulder
• ✓Limit the space between your vehicle and the side of the road throughout the manoeuvre

To turn left, steer into the left lane, check both directions, keep the front end close to the dividing line, and edge to the right side of the entered lane. Keep rear wheels off the centre line. You may need to trespass into the far right-hand lane, but other vehicles turning left beside you or turning right from opposite have the right of way.

• ✓Keep the front end close to the dividing line and edge to the right side of the entered lane
• ✓Ensure rear wheels do not cross over the centre line until the turn is almost complete
• ✓If trespassing into the far right-hand lane, vehicles turning left beside you or turning right from opposite have right of way

Double road trains handle differently from other heavy vehicles, especially on slippery surfaces where they spin or skid more easily.

• ✓Wheels are more likely to spin when starting on slippery pavement
• ✓A double road train is more likely to skid on level roads, grades, snow or wet pavement
• ✓Always drive safely and defensively to anticipate and avoid hazards
• ✓Any delay in correcting a threatening situation can result in an accident

Although more wheels give greater braking capacity in theory, more axles and articulations make it harder to brake evenly in practice.

• ✓More axles/articulations make it harder to stop tractor and trailers evenly and simultaneously
• ✓Avoid abrupt braking or prolonged brake application to keep braking efficiency
• ✓Constantly monitor traffic, adjust speed, and leave enough space ahead
• ✓Check mirrors each time you brake to see how the semi-trailers react

Professional drivers determine following distance in seconds based on vehicle length, allowing one second per three metres.

• ✓Divide the vehicle length in metres by three to get the interval in seconds
• ✓A 24 m double road train requires an 8-second interval (24 / 3 = 8)
• ✓Pick a roadside reference point and count 'one thousand and one...' until the interval
• ✓If you reach the reference point too soon, you are following too closely

Locking different wheels of a double road train produces different dangerous outcomes, so preventing lock-up is critical.

• ✓If the tractor's front wheels lock, you cannot steer properly
• ✓If the tractor's back wheels lock, the vehicle could jackknife
• ✓If the second semi-trailer's wheels lock, it may begin fishtailing
• ✓Keep the brake system in good order and distribute load properly to avoid lock-up

Retarders act only on drive wheels; on slippery roads some types can cause drive wheels to lock up and jackknife the vehicle. Most tractors and semi-trailers have ABS for greater stability, better steering control, and shorter braking distances, but you must stay alert to take control.

• ✓Retarders act only on the drive wheels and can cause lockup and jackknifing on slippery roads
• ✓ABS provides greater stability, better steering control and generally shorter braking distances
• ✓Check mirrors each time you brake to see how the semi-trailers react

A pup semi-trailer can overturn if you steer sharply to avoid an obstacle. Reduce risk with hard tires, proper suspension, axle and fifth wheel adjustment. Also scan the road ahead, reduce speed, change lanes early, and avoid turning the steering wheel more than necessary or sharply.

• ✓Steering sharply to avoid an obstacle risks overturning the pup semi-trailer
• ✓Reduce risk with hard tires and proper suspension, axle placement and fifth wheel adjustment
• ✓Avoid turning the steering wheel more than necessary or sharply when manoeuvring around obstacles
• ✓Scan the road ahead, reduce speed, and change lanes early when detecting a hazard

Longer vehicles need more time and distance to overtake, but other drivers often misjudge this and pull back in too soon. To help, reduce speed and stay in the right-hand lane without edging onto the shoulder. On wet roads stay out of ruts to avoid splashing passing vehicles.

• ✓Reduce speed and stay in the right-hand lane to make it easier for others to pass
• ✓Do not edge over onto the shoulder while being passed
• ✓On wet roads, stay out of ruts to avoid splashing water onto passing vehicles

Pass only where road signs allow and obey speed limits. Ensure you can overtake safely, check no one is overtaking you, ensure enough accelerating power, and allow enough space behind before returning to the right lane.

• ✓Pass only where road signs allow it and obey the speed limits
• ✓Ensure your vehicle has enough accelerating power to pass
• ✓After overtaking, allow enough space behind you before pulling back into the right lane

Bumpy roads, high winds or abrupt steering can make the second semi-trailer weave back and forth (fishtailing), which can escalate to overturning.

• ✓Fishtailing can be triggered by bumpy roads, high winds or abrupt steering turns
• ✓Fishtailing may increase gradually until the second semi-trailer overturns
• ✓Fishtailing may be hard to detect immediately, reducing reaction time
• ✓Stay focused on the road and check mirrors regularly to maintain control

Due to the large size and stability concerns of LCVs, specific speed and following distance rules are mandated to protect all road users and allow safe stopping.

• ✓Must travel at a maximum speed of 90 km/h
• ✓Must maintain at least 150 m from any road vehicle ahead, except when passing
• ✓Should maintain even greater distance when weather or road conditions require

To maintain reasonable speeds especially on uphill grades, LCV tractors must meet a minimum power-to-weight ratio set by regulation.

• ✓Tractor must have a minimum of 1 HP per 180 kg of total loaded mass
• ✓This equals 375 HP for a combination with total loaded mass of 67,500 kg

Peace officers may stop heavy vehicle drivers for roadside inspections to ensure road safety, remove vehicles with major defects, verify noted defects, and confirm regulatory compliance. Officers can check documents, information accuracy, compliance, and vehicle condition.

• ✓A peace officer may check the presence and accuracy of the circle check report and relevant defect lists on board
• ✓Officers verify regulatory compliance (e.g., operating despite a major defect) and inspect the vehicle's condition
• ✓Roadside inspections aim to remove vehicles with major defects from the road

If overbraking caused the skid, let up on the brake pedal so wheels turn again and tires grip. If rapid downshifting caused it, press down on the clutch and use the brake as needed. If overaccelerating caused it, slowly release the accelerator, changing gears as needed to keep wheels from spinning.

• ✓Overbraking skid: let up on the brake pedal to restore traction
• ✓Downshifting skid: press down on the clutch, use brake as needed
• ✓Overaccelerating skid: slowly release the accelerator
• ✓Once control is regained, shift into the appropriate gear

When the rear end veers left or right, turn the steering wheel in the same direction the vehicle is skidding to pull it back into line, then countersteer as the vehicle straightens. If the rear skids left, steer left then correct right; if the rear skids right, steer right then correct left.

• ✓Turn the steering wheel in the same direction the rear of the vehicle is skidding
• ✓When the vehicle is almost back in line, turn the wheel the opposite way to straighten front wheels
• ✓Rear skidding left: steer left first, then right to straighten
• ✓Rear skidding right: steer right first, then left to straighten

When defensive driving fails to prevent a skid, the first thing to do is determine its cause—overbraking, rapid downshifting, or overaccelerating—so you can apply the correct recovery technique.

• ✓First determine the cause of the skid before reacting
• ✓Recovery technique depends on the cause of the skid

Due to the large size and stability considerations of LCVs, specific speed and distance rules apply to protect all road users.

• ✓Maximum speed for an LCV is 90 km/h
• ✓Must maintain a distance of at least 150 m from any road vehicle ahead, except when passing
• ✓Maintain even greater distance when weather or road conditions require

LCV drivers face restrictions on when they may drive, including holidays and peak traffic periods in major cities.

• ✓Prohibited from driving on December 26 or statutory holidays
• ✓Prohibited from travelling on roads where LCVs are not authorized
• ✓In Québec city: no highway driving Mon-Fri from 6:30-9:00 a.m. and 3:30-6:00 p.m.
• ✓On the island of Montréal: no highway driving Mon-Fri from 5:30-9:30 a.m. and 3:00-7:00 p.m.

LCV drivers must only operate under clear conditions and clean roadways, with extra rules during winter months.

• ✓Visibility must be clear for a distance of 500 m or more
• ✓The roadway must be free of snow and ice
• ✓Additional winter rules apply from December 1 to February 29

To maintain reasonable speed, especially uphill, the tractor must have adequate horsepower relative to loaded mass.

• ✓Tractor must have a minimum of 1 HP per 180 kg of total loaded mass
• ✓This represents 375 HP for a combination with a total loaded mass of 67,500 kg

LCVs are restricted from carrying dangerous substances in placard-requiring quantities.

• ✓Transportation of dangerous substances is prohibited in an LCV if the quantity requires display of safety mark placards

Certain inspections are mandatory during a trip. Drivers must stop in areas designated by the VÉRIFICATION road sign to test their brakes and perform a braking system inspection as done during the circle check. This check takes only a few minutes and can be done from the cab.

• ✓Stop in areas designated by the brake test road sign to test brakes
• ✓Perform a braking system inspection as done during the circle check
• ✓The brake check can be carried out from the cab in a few minutes

During a trip, check wheel temperature to confirm adequate brake adjustment and no risk of losing a wheel. Look for lubricant near wheel hubs, and check for intense heat, smoke, or burnt smell. Lubricant traces may mean a damaged hub ring seal or a wheel bearing about to slip out of the cup.

• ✓Check wheel temperature to verify brake adjustment and wheel security
• ✓Ensure no traces of lubricant near wheel hubs
• ✓Check for intense heat, smoke, or burnt smell from wheels
• ✓Lubricant near a hub may indicate a damaged seal or failing wheel bearing

If one wheel produces more heat than others, the wheel bearing may be faulty or the brake misadjusted. Wait for the wheel to cool before doing a thorough check to determine the cause and ensure you can continue safely.

• ✓A hotter wheel indicates a possible faulty bearing or misadjusted brake
• ✓Wait for the wheel to cool before checking thoroughly
• ✓Confirm safety before continuing

If a wheel has recently been changed, check its tightness after travelling between 80 and 160 km. Wheels should preferably be tightened by a mechanic in accordance with the manufacturer's standards.

• ✓Check tightness of a recently changed wheel after 80 to 160 km of travel
• ✓Wheels should preferably be tightened by a mechanic per manufacturer standards

Progressive shifting is better suited to modern engines than revving to maximum RPM. You bring engine speed almost up to minimum torque when shifting through the first 3–4 gears, and for higher gears increase RPM to at or slightly above minimum torque. It reduces shift time and reaches cruising speed faster.

• ✓Do NOT rev to maximum RPM before shifting (old method)
• ✓Bring engine near minimum torque for first 3-4 gears
• ✓Increase RPM to at/slightly above minimum torque for higher gears
• ✓Reduces time to reach cruising speed and saves fuel

The biggest fuel savings occur on highways. Staying at 90 km/h or under minimizes wear on engine, tires and brakes and saves fuel. Reducing cruising speed from 105 km/h to 90 km/h cuts fuel consumption by an average of 10%.

• ✓Stay at 90 km/h or under to save fuel and reduce wear
• ✓Reducing from 105 to 90 km/h cuts fuel use by ~10%
• ✓Extra driving time added is minimal

Check the accelerator's working order. With the vehicle stationary (parking brake engaged), engine running, transmission in neutral, press the accelerator (not to maximum rpm), release it, and confirm the engine returns to idle by watching the tachometer (or listening if none).

• ✓Defect 4.A (major): The engine does not return to idle after the accelerator is released
• ✓Defect 4.1 (minor): The engine does not accelerate or return to idle in a normal manner when released

Covers vehicles with manual (standard) transmission. Check clutch working order: engage parking brake, put transmission in neutral, press clutch and start engine, shift into gear, release parking brake, let vehicle move forward by delicately and completely releasing the clutch, then press clutch and brake to stop, shift to neutral, apply parking brake. Any gear slip not correctable by adjustment represents wear affecting proper working order.

• ✓Defect 4.1 (minor): The clutch mechanism is not in proper working order
• ✓Uncompensated gear slip indicates wear that can hamper proper working order

Check the working order of the horn by activating it in the driver's compartment. The mandatory inspection only covers working order, not the physical aspect or mounting of horns. If equipped with two horns, at least one must be checked.

• ✓Defect 4.2 (minor): The horn is not working
• ✓If the vehicle has two horns, at least one must be checked; anomalies affecting solidity should be reported

The circle check meets the minimum standards in the Regulation respecting safety standards for road vehicles. Its goal is to prevent a vehicle with defects that may endanger road users from being operated. The suggested 10-step method lets you completely circle the vehicle; it is not mandatory but helps meet obligations efficiently.

• ✓The circle check meets the minimum standards set out in the Regulation respecting safety standards for road vehicles
• ✓No specific method is mandatory, but the method used must allow all required inspections to be done effectively

Park on flat, safe ground to perform the circle check and watch nearby traffic if close to a roadway. Apply the parking brake to the entire vehicle from the start. During inspection it may be necessary to release the parking brake on vehicles with air suspension or air brakes to allow air intake, but always ensure the vehicle remains immobile even on flat ground.

• ✓Choose a flat, safe location and apply the parking brake to the entire vehicle before starting
• ✓When releasing the parking brake to allow air intake, ensure the vehicle remains immobile

Always use three support points when climbing onto or off the vehicle and avoid climbing on tires or parts not intended for that purpose. Pay special attention to air leaks (brakes, suspension, tires) and fluid leaks on the ground, around wheel hubs, or on tanks, which indicate defects with potential major consequences such as flat tires, wheel loss, brake failure or suspension breakage.

• ✓Always use three support points to climb onto or off the vehicle
• ✓Watch for air leaks and fluid leaks (oil, grease, fuel) that signal major potential defects
• ✓Inform the vehicle owner or operator of any anomalies detected, even outside the mandatory checks

During the spring thaw, road resistance decreases by 40% and roads are especially vulnerable to heavy vehicle weight. A truck's impact during thaw equals several trucks in normal conditions, so stricter load limits are enforced to prevent serious road damage.

• ✓Road resistance decreases by about 40% during spring thaw
• ✓A single overloaded truck can cause serious road damage during thaw
• ✓Stricter load limits are enforced during the spring thaw period

The load restriction period is usually March to May, adjustable by weather. Québec is divided into three zones: Zone 1 (southern Québec to Rivière-du-Loup), Zone 2 (north of Zone 1 including Saguenay, Gaspésie, Côte-Nord), and Zone 3 (north of Zone 2 including Abitibi, Chibougamau-Chapais). Consult Transport Québec for load limits.

• ✓Load restriction period is usually March to May, adjustable by weather
• ✓Québec is divided into three spring thaw zones
• ✓Load limits are based on vehicle configuration and axle type per the Vehicle Load and Size Limits Regulation

The circle check meets the minimum standards of the Regulation respecting safety standards for road vehicles. Its goal is to prevent a vehicle with defects that may endanger road users from being put into operation. The suggested safe 10-step method lets you completely circle the vehicle; it is not mandatory but helps meet obligations.

• ✓The circle check must be thorough and well understood
• ✓The suggested 10-step method is not mandatory; another equally effective method may be used