Vehicle and Load Dimensions +8British Columbia · CDL · English

The Commercial Transport Act sets limits for commercial vehicle lengths, widths, heights and weights. Drivers must obey all Ministry of Transportation signs that limit dimensions or weight, regardless of the licence or permit held. Temporary additional weight restrictions may be posted at certain times of the year.

• ✓Obey all Ministry of Transportation signs limiting dimensions or weight regardless of the licence or permit you carry
• ✓Temporary additional weight restrictions can be posted at certain times of the year
• ✓Signs help avoid damaging your vehicle, its load, the road or other highway users

You must know the height of your vehicle and load at all times. The maximum allowable height for a commercial vehicle is 4.15 m unless you have an oversize load permit. Highway signs before underpasses and tunnels give overhead clearance heights, and check bars/warning devices help test clearance.

• ✓Maximum allowable height for a commercial vehicle is 4.15 m unless the driver has an oversize load permit
• ✓Know the height of your vehicle and its load at all times
• ✓Diamond-shaped signs warn of low clearance ahead; rectangular signs may be mounted on the structure

The maximum legal width of a vehicle and its load is 2.6 m unless you have an oversize load permit. Certain items may extend up to 10 cm beyond the sides without being counted in overall width. Loose hay/straw/fodder loads can be up to 3.1 m wide. Side mirrors must always extend beyond your load.

• ✓Maximum legal width of a vehicle and its load is 2.6 m unless the driver has an oversize load permit
• ✓Items like anti-splash devices, load securing devices, ladders, placards, glad hands, connectors and clearance lights may extend up to 10 cm beyond the sides
• ✓Vehicles transporting loose hay, straw or fodder can be loaded to a maximum of 3.1 m overall width
• ✓Side mirrors may extend up to 20 cm beyond the side; if more than 20 cm they count in overall width
• ✓Side mirrors must always extend beyond your load so you can see behind

Commercial vehicles are licensed according to their gross vehicle weight (GVW). You must know your vehicle and load weight to avoid exceeding limits. GVW is the combined weight of vehicle and load; GVWR is the manufacturer's rating; Licensed GVW is the maximum weight licensed to carry or tow.

• ✓GVW (gross vehicle weight) is the combined weight of the vehicle and its load
• ✓GVWR (gross vehicle weight rating) is a manufacturer's rating defining vehicle weight and maximum load
• ✓Licensed GVW is the combined weight licensed to carry or tow; minimum licensed GVW of most commercial vehicles is 1.5 times the net weight of the vehicle
• ✓Watch for maximum allowable weight signs when approaching bridges

Always be aware of your vehicle's length and load length. Be particularly cautious when negotiating turns on narrow roads and in alleys. Leave enough clearance to avoid striking objects like poles, parked cars and buildings.

• ✓Be particularly cautious while negotiating turns on narrow roads and in alleys
• ✓Leave enough clearance to avoid striking objects such as poles, parked cars and buildings
• ✓Overall length for reefer vans or trailers may be extended to include the refrigeration or heating unit

If a line rupture causes total loss of primary reservoir pressure, the secondary reservoir is protected by the one-way check valve. Only the steering axle brakes will apply, allowing a controlled stop with longer stopping distances. If the failure were in the secondary system, rear axle braking would be maintained but steering axle brakes would not operate.

• ✓With primary failure, only steering (front) axle brakes apply and stopping distances increase
• ✓If the low-air warning activates, stop immediately and do not proceed until repaired

ABS has three sections: speed sensing, decision-making, and brake releasing/modulation. Magnetic pickups sense wheel speed via toothed wheels. When lockup occurs, the ECU signals solenoid valves (modulators) to release air pressure. Systems can cycle up to five times per second. To stop shortest on slippery surfaces, apply firm continuous pressure. ABS prevents lockup, retaining steering control.

• ✓Apply and maintain firm continuous pressure on the brake pedal to let ABS work
• ✓ABS can cycle the brakes up to five times per second
• ✓If the ABS lamp stays on or comes on during operation, only the anti-lock feature is disabled — normal braking still works
• ✓ABS prevents axle brakes from locking, allowing the driver to retain steering control

Air dryers are installed in the compressor discharge line between the compressor and first reservoir. They remove water vapour, oil mist and carbon particles from air. When the reservoir reaches full pressure, a purge port opens to eject contaminants. A reverse flush cleans the filters. In systems with an air dryer, the safety valve is often installed at the dryer. Some have electric heating elements to prevent freezing.

• ✓Air dryers are installed between the compressor and the first reservoir
• ✓Air reservoirs should still be drained regularly even with an air dryer
• ✓More than a few drops of water indicates air dryer or compressor needs servicing
• ✓In dryer systems, the safety valve is often at the air dryer rather than supply reservoir

These optional systems reduce steering axle brake lockup on slippery surfaces. Automatic systems use a limiting/ratio valve near the steering axle with no dashboard control. Below 40 p.s.i. application, steering axle pressure is approximately 50% of drive axle pressure. Above 40 p.s.i., the percentage rises until at emergency stop pressures (60-70 p.s.i.) both axles receive equal pressure.

• ✓Below 40 p.s.i. application, steering axle brake pressure is approximately 50% of drive axle pressure
• ✓At emergency stop pressures (60-70 p.s.i.) steering and drive axles receive equal pressure
• ✓Automatic systems have no dashboard control; use a limiting/ratio valve near the steering axle

No longer installed on new vehicles, these use a limiting quick-release valve and dash-mounted control valve. 'Dry' position applies equal pressure to steering and drive axles. 'Slippery' position limits steering axle to 50% of drive axle. Under the Motor Vehicle Act, the slippery position may only be used when weather conditions make its use essential for safety.

• ✓Slippery/reduced position may only be used when weather conditions make it essential for safety
• ✓Dry position applies full/equal pressure to steering axle brakes
• ✓Keep the control in the normal Dry Road position for normal braking efficiency

Installed between service brake reservoirs and non-essential air accessories (air seats, horns, wipers, suspensions, fifth wheel sliders, air shifts). They cut off air supply if a failed accessory drops service reservoir pressure below a preset level, ensuring sufficient pressure for a safe stop. Shutoff pressures vary between 60 and 90 p.s.i.

• ✓They cut off air to accessories if service reservoir pressure drops below preset level
• ✓Shutoff pressures vary between 60 and 90 p.s.i. (414 and 620 kPa)
• ✓They ensure sufficient pressure is maintained for a safe stop

Trucks and tractors have a dash-mounted ABS failure warning lamp. On ignition, the system self-checks — the lamp may light, flash briefly then stay lit until 7-11 km/h, or light briefly then turn off. If the lamp doesn't go out or comes on while driving, there is an ABS failure and the vehicle may be driven to a service depot.

• ✓ABS lamp performs a self-check when ignition is first turned on
• ✓Lamp may stay lit until vehicle speed reaches 7-11 km/h then turn off
• ✓If lamp doesn't go out, there is an ABS failure but normal braking still works

Trailer ABS uses similar components as trucks/tractors. The ECU may be powered from the stop lamp circuit or a dedicated source. Trailers have an indicator visible in the tractor mirror if the system malfunctions, mounted on the front or rear left side. Some tractors have a dashboard trailer ABS indicator. Always check if a trailer has ABS when coupling.

• ✓Trailer ABS warning light is visible in the tractor's side mirror
• ✓Always check if the trailer is ABS-equipped when coupling
• ✓Emergency stopping differs between all-ABS combinations and non-ABS combinations

Modern integrated air dryer systems combine spin-on filter, dryer and governor into one unit with a purge reservoir. The wet/supply reservoir isn't needed. Pressure protection valves protect primary and secondary service reservoirs. One service reservoir fills first; at approximately 100 psi the other begins to fill. Maximum pressure may be up to 135 psi.

• ✓Pressure protection valves are factory set and shouldn't be adjusted
• ✓One service reservoir fills first, then at approximately 100 psi the other fills
• ✓Maximum pressure may be up to 135 psi

These optional devices introduce alcohol vapour that combines with moisture, acting as anti-freeze to lower the freezing point. Evaporators connect to the compressor inlet; injectors install in the discharge line using a venturi. Keep the alcohol reservoir topped with methyl hydrate in winter, starting before the first freeze.

• ✓Air reservoirs must still be drained regularly even with alcohol evaporators/injectors
• ✓Only use methyl hydrate specifically formulated for use in these systems
• ✓Begin topping up before the first freeze of the season

Automatic drain valves (spitter valves) intermittently expel collected contamination. Most open briefly each time reservoir pressure lowers two or three p.s.i., but some connect to the governor and open each compressor cycle. Some have electric heating elements. Manual drains should still be opened periodically to check for water.

• ✓Most open when reservoir pressure lowers two or three p.s.i. (13.8 or 20.7 kPa)
• ✓Manual drains should be opened periodically to check for water
• ✓Contaminants or water indicate compressor, air dryer, or drain valve may need servicing

This provides an emergency release tank to release spring parking brakes if main reservoir pressure is lost and a disabled vehicle must be moved. A second dashboard control valve directs air from the emergency tank. Usually a 'dead man' type that must be held while moving. Also called 'California spring parking brake systems.'

• ✓The control valve is usually a 'dead man' type that must be held while the vehicle moves
• ✓Releasing hand pressure re-applies the spring parking brakes
• ✓Used on transit buses, school buses and fire trucks

The driver must determine the vehicle is in safe operating condition before driving. The National Safety Code (NSC) requires most commercial vehicles be inspected daily. Both driver and carrier share responsibility for proper inspections.

• ✓You must determine your vehicle is in safe operating condition before you drive it
• ✓NSC vehicles must be inspected before use each day (pre-trip) and at the end of the final trip of each day (post-trip)
• ✓Inspections may be done by you or another person specified by the carrier; driver and carrier share responsibility

Certain commercial vehicles require daily written inspection reports based on type and weight, including large passenger vehicles and heavy trucks/truck-tractors.

• ✓Buses/limousines with seating capacity over 10 including driver require written reports
• ✓Two-axle truck or truck-tractor with licensed GVW greater than 14,600 kg requires written reports
• ✓Truck or truck-tractor towing a trailer with licensed GVW greater than 8,200 kg requires written reports

Under the NSC, all vehicles transporting cargo on a highway, regardless of GVW, must be inspected for cargo securement. Cargo must be re-inspected at set intervals during the trip.

• ✓Re-inspect cargo securement within 80 km from the loading point
• ✓Re-inspect at the earliest of: a change in driver duty status, three hours of driving, or 240 km since last inspection
• ✓Record cargo securement inspections on your daily logs
• ✓No inspection needed if cargo is sealed with orders not to inspect, or if cargo is inaccessible

Look under the vehicle for leaks as you approach. Check fluid levels and condition (engine oil, coolant, power steering fluid, brake fluid, washer fluid). Inspect belts for tension and cracks, hoses for secure connections and no leaks, and steering components (shaft, box, tie-rods, idler arm) for security and no bends/cracks. Check suspension at all wheels for cracked/missing springs, torsion bars, walking beams, U-bolts and airbags. Check frame for cracks/holes. Inspect tires, wheels and mud flaps.

• ✓Check all fluid levels and condition, belts, hoses and steering components
• ✓Inspect suspension for broken/missing springs, U-bolts and air bags; frame for cracks and broken welds
• ✓Check tires for inflation, bulges, tread depth, wheels for cracks and secure lugs; rust streaks may indicate loose wheel nuts

A Class 2 pre-trip inspection should be completed in less than 30 minutes; a Class 4 (unrestricted) in less than 20 minutes. If the bus has air brakes, also complete the Class 3 air brake procedures, and you must demonstrate setting up a slack adjuster. Before beginning: set parking brakes, shut off the engine and block the wheels. Remove keys from the ignition when checking underneath.

• ✓Complete Class 2 inspection in under 30 minutes; Class 4 unrestricted in under 20 minutes
• ✓Set parking brakes, shut off engine and block wheels before beginning
• ✓If air-brake equipped, demonstrate setting up a slack adjuster and follow Class 3 air brake procedures

Turn ignition on and start engine. Verify gauges/warning lights respond properly: charge rate (voltmeter/ammeter), oil pressure (normal soon after start), coolant temperature (rises to normal, light off after start), and fuel gauge shows sufficient fuel. Check instrument lights, windshield wipers/washers, heater/defroster, interior lights (dome, courtesy, step), horn, four-way flashers and school bus stop sign if equipped.

• ✓Oil pressure must indicate normal soon after start; coolant temperature light must go off after start
• ✓Charge rate, fuel gauge, instrument lights, wipers, defroster, horn and flashers must all function
• ✓School bus stop sign (if equipped) must work and be secure

Check that emergency equipment is in working condition: warning devices (flags or flares), fire extinguisher with a valid date on the label, and a first aid kit with adequate contents. A peace officer may place a vehicle out of service if drum brake linings are less than 1/4 inch (6.4 mm) thick or air disc brake pads are less than 1/8 inch (3.2 mm) thick.

• ✓Warning devices, fire extinguisher (valid date) and first aid kit (adequate contents) must be present and functional
• ✓Drum brake linings under 1/4 inch (6.4 mm) or air disc pads under 1/8 inch (3.2 mm) may result in out-of-service

Check passenger seats are securely fastened with no broken frames, seatbelts (if equipped), and cleanliness. Ensure passenger doors and entrances open/close properly, step lights work and hand rails are secure. Verify emergency windows are secure and open emergency exits (where feasible) to confirm the emergency alarm sounds.

• ✓Passenger seats must be secure with no broken frames; doors, step lights and hand rails must function
• ✓Emergency windows and exits must be secure, and opening emergency exits should trigger the alarm

With engine started, in low gear gently tug against the parking brakes — they should prevent the bus from moving. Release brakes, move the bus ahead slowly and apply the foot brake to check response. Move the steering wheel to check for excessive slack or lash. Remove wheel blocks with parking brakes set before beginning.

• ✓Parking brakes must hold the bus during a gentle tug test in low gear
• ✓Check foot brake response by moving ahead slowly and check steering wheel for excessive slack

Large vehicles travelling at high speeds create air turbulence hazardous to smaller vehicles. The larger the vehicle, the more wind turbulence. Road users directly in front of a truck, alongside the cab, at the back of the trailer, or immediately behind the trailer are in areas of air turbulence and may be forced off the road or drawn into the vehicle.

• ✓Larger vehicles create more wind turbulence
• ✓If a smaller vehicle rides in your turbulence area, slow down until it's clear
• ✓Be alert for cyclists who may lose control in your air turbulence

Drivers often think big vehicles are going faster than they are. When passing, observe the speed limit and avoid startling nervous drivers. Don't occupy the fast lane unnecessarily when passing another commercial vehicle. When other drivers want to pass, help by reducing speed and giving room, but don't direct them into an unsafe pass.

• ✓Observe speed limits and avoid startling inexperienced drivers when passing
• ✓Don't occupy the fast lane when it isn't absolutely necessary
• ✓Reduce speed and give room to help others pass safely
• ✓Use four-way flashers to warn drivers if you can't keep up with traffic

Fuel efficiency begins when starting the engine; proper warm-up lubricates components and saves fuel.

• ✓Use zero throttle when starting — don't pump the throttle as it wastes fuel and isn't effective
• ✓Let the engine warm up three to five minutes only, or seven to 10 minutes if below 0°C — any longer wastes fuel and can cause damage
• ✓Use ether sparingly if operating in cold temperatures and only if the owner's manual permits it, as it can damage the engine
• ✓Check that oil and air pressure rise to their normal operating ranges

Proper driving keeps you safe and reduces fuel consumption through smooth acceleration and correct gear use.

• ✓Accelerate slowly keeping engine rpm down; practise progressive gear shifting (shifting before reaching maximum governed rpm)
• ✓Run the engine in the highest gear range to keep it in a low rpm range and always use the clutch to avoid wearing gear teeth
• ✓Back off the throttle over the top of a hill and select a lower gear to descend; use the retarder properly and turn it off when not needed
• ✓Use the see-think-do method to anticipate hazards and maintain constant speed — power not used is fuel not burned

Turning the engine off when not driving is more economical than leaving it running. Idling wastes fuel and money.

• ✓Turn off the engine when stopped for any length of time to save fuel, reduce maintenance, prolong engine life and prevent emissions
• ✓Idling can burn up to four litres of fuel per hour
• ✓Many trucks have auxiliary power units to run air conditioning or refrigeration without idling the engine

Regular maintenance keeps the vehicle running well and maintains fuel efficiency.

• ✓Keep tires inflated to manufacturer recommendations — for every 10 p.s.i. (69 kPa) underinflated, one per cent of fuel is wasted
• ✓It is the law to do a pre-trip inspection before driving; conduct enroute inspections including tires and cargo at least every three hours
• ✓Check for air leaks which reduce brake effectiveness and make the compressor run longer, reducing fuel efficiency
• ✓Low-viscosity lubricants such as synthetic motor oil can improve fuel economy by up to four per cent

Fuel efficiency begins when you start the engine. Proper warm-up lubricates components, reduces wear and leakage and saves fuel. Use zero throttle and don't pump the throttle. Use ether sparingly in cold temperatures as it can damage the engine.

• ✓Use zero throttle when starting and don't pump the throttle as it wastes fuel
• ✓Let the engine warm up for three to five minutes only, or seven to 10 minutes if temperature is below 0°C
• ✓Check that oil and air pressure rise to normal operating ranges before driving
• ✓If adding ether in cold temperatures, use it sparingly and check the owner's manual to see if it's permitted

Proper driving reduces fuel consumption. Accelerate slowly, choose the right gear, use progressive gear shifting, and ease off the throttle. Use the see-think-do method to anticipate hazards and maintain constant speed, preserving momentum.

• ✓Practise progressive gear shifting (shifting before reaching maximum governed rpm) to reduce wear, decrease noise and save fuel
• ✓Always use the clutch, since failing to use it wears down transmission gear teeth
• ✓Back off the throttle going over the top of a hill and select a lower gear to go down
• ✓Changing gears smoothly can improve operating costs by 30 per cent

Adjust driving to visibility, keep the seat adjusted, keep eyes moving to check hazards, and maintain a safe following distance. Anticipate stops and traffic lights to avoid unnecessary braking.

• ✓Drivers of buses, trucks and other large heavy vehicles should never be less than five seconds behind the vehicle ahead at highway speeds
• ✓It's more fuel efficient to let off the throttle to gradually slow down than to apply the brakes at the last minute
• ✓Anticipate red lights by gradually slowing down to avoid a complete stop when the light may turn green

Regular maintenance keeps the vehicle running well and maintains fuel efficiency. Correct tire pressure and fluid levels are critical. Pre-trip, enroute and post-trip inspections help avoid breakdowns and detect problems affecting fuel use.

• ✓For every 10 p.s.i. (69 kPa) underinflated, one per cent of fuel is wasted
• ✓It's the law to do a pre-trip inspection before driving
• ✓Conduct enroute inspections including tires and cargo at least every three hours
• ✓Check for air leaks which affect air brake effectiveness and make the compressor run longer, reducing fuel efficiency

Fuel-efficient driving controls costs and reduces environmental impact. Nearly 30 per cent of Canada's greenhouse gas emissions come from motor vehicles.

• ✓Fuel-efficient driving techniques can improve fuel economy by up to 30 per cent
• ✓Fuel-efficient driving is also safe driving — looking ahead and keeping good space margins avoids sudden stops and speed changes

Choosing the correct fuel for the season and planning efficient routes reduces fuel consumption.

• ✓Use the correct fuel for the season — summer fuel improves economy by up to 3 per cent but can cause engine problems in cold weather
• ✓Plan routes to avoid heavy commuter traffic, busy city driving and hills; flat highway routes are more fuel efficient than mountainous or congested routes
• ✓Consider biodiesel which provides similar power but contributes less carbon dioxide and sulfur
• ✓Snow-covered roads can increase fuel consumption by 15 to 20 per cent

Equipment options and aerodynamic features significantly affect fuel consumption, especially at highway speeds.

• ✓At 90 to 100 km/h, about 50 per cent of fuel consumed overcomes air resistance; aerodynamic features can improve economy by 15 to 20 per cent
• ✓Rib tread tires are more fuel efficient than lug tread on drive and steering axles; super-single tires offer lower rolling resistance
• ✓Keep flatbed loads low and covered with a tarpaulin to improve aerodynamics
• ✓Aerodynamic drag increases if wheels on a tractor-trailer aren't properly aligned and tracking parallel to travel direction

Fuel-efficient driving techniques can improve fuel economy by up to 30 per cent. Nearly 30 per cent of all greenhouse gas emissions in Canada are produced by vehicles. Fuel-efficient driving is also safe driving through looking ahead, keeping good space margins and anticipating hazards.

• ✓Fuel-efficient driving techniques can improve fuel economy by up to 30 per cent
• ✓Smart fuel-efficient driving includes trip planning, proper maintenance, proper starting techniques, proper driving techniques and reducing idle time

Use the correct fuel for the season; summer fuel can improve fuel economy by up to three per cent but causes problems in cold weather. Consider biodiesel which produces less carbon dioxide and sulfur. Plan routes to avoid heavy traffic, city driving and hills.

• ✓Use the correct fuel for the season and location since summer fuel can cause engine problems in cold weather
• ✓Flat routes are more fuel efficient than mountainous routes, and highway driving is more efficient than congested city streets
• ✓Driving on snow-covered roads can increase fuel consumption by 15 to 20 per cent

Turning the engine off when not driving is more economical than leaving it running. Idling wastes fuel and money. Many trucks have auxiliary power units to run air conditioning or refrigeration.

• ✓Turn off the engine when stopped for any length of time to save fuel, reduce maintenance, prolong engine life and prevent emissions
• ✓Idling can burn up to four litres of fuel per hour

At 90 to 100 km/h, about 50 per cent of fuel is used to overcome air resistance. Aerodynamic features like sloped hoods, rounded bumpers, roof fairings, side skirts and rear air dams significantly reduce fuel use. Tire choice and accessories also matter.

• ✓Aerodynamic features can improve fuel economy by 15 to 20 per cent
• ✓Keep flatbed loads low and cover with a tarpaulin to improve aerodynamics
• ✓Rib tread tires are more fuel efficient than lug tread tires on drive and steering axles
• ✓Aerodynamic drag increases if wheels aren't properly aligned and tracking parallel to the direction of travel

If you do not qualify on a knowledge test, pre-trip or road test, you must wait a set period before another attempt. The waiting period increases with repeated unsuccessful attempts and varies by test type.

• ✓Knowledge tests and pre-trips require a 7-day wait after every unsuccessful attempt
• ✓Class 1–4 road tests require 14 days after the 1st failure and 30 days after the 2nd and subsequent failures
• ✓Endorsement 20 road tests require 14 days after 1st, 30 days after 2nd, and 60 days after 3rd or more failures

Large vehicles travelling at high speeds create air turbulence hazardous to smaller vehicles; the larger your vehicle, the more turbulence. Cars, bicycles or others in front of the truck, alongside the cab, near the back of the trailer or at the immediate rear are in areas of turbulence and may be forced off the road or drawn into your vehicle. If a smaller vehicle rides in your turbulence area, slow down until it's out.

• ✓The larger the vehicle, the greater the wind turbulence it creates
• ✓Slow down until a smaller vehicle riding in your turbulence area is clear

Drivers often think big vehicles are travelling faster than they are. When overtaking passenger vehicles, observe the speed limit and avoid startling inexperienced drivers. Avoid occupying the fast lane unnecessarily when passing another slow truck, which congests traffic. Use four-way flashers to warn drivers if you can't keep up with traffic.

• ✓Observe the speed limit when passing and avoid startling other drivers
• ✓Don't occupy the fast lane unnecessarily when passing at similar speeds
• ✓Use four-way flashers if you can't keep up with traffic

When other drivers indicate they want to overtake, help them pass safely by reducing speed and giving room. Don't wave others to pass, as this may encourage a pass they can't complete safely.

• ✓Reduce speed and give room when another driver wants to pass
• ✓Don't direct others to pass, as it may encourage an unsafe pass