Norway Theory Test - Category C key terms

The combined weight of a vehicle plus its load at any given moment, including driver, passengers, fuel and cargo. It must never exceed the vehicle's permitted maximum total weight.

The maximum weight of cargo, passengers and equipment a vehicle may carry, calculated as permitted total weight minus kerb weight. Overloading reduces braking performance and can void insurance cover.

The weight of a vehicle with fuel, coolant, oils and standard tools but without driver, passengers or cargo. It is the figure used to work out how much payload remains available.

The weight carried by a single axle or axle group, measured where the tyres touch the road. Each axle has a permitted maximum, and exceeding it damages roads and tyres and is fined.

The combined load carried by two closely spaced axles that share a suspension, common on trailers and semi-trailers. It has its own permitted maximum separate from the individual axle limits.

The highest speed a vehicle is legally allowed to travel, set by road sign, general rule or the vehicle's construction. For heavy vehicles it is often lower than the general limit and marked on the vehicle.

Choosing a speed to match visibility, road surface, traffic, load and weather rather than simply driving at the posted limit. In poor conditions the safe speed is often well below the legal maximum.

The gap to the vehicle ahead, normally at least three seconds in good conditions and more when heavy, wet or icy. Heavy vehicles need longer stopping distances, so the gap must increase.

The distance a vehicle travels from the moment the brakes are applied until it stops. It grows with the square of speed and is much longer for a fully loaded heavy vehicle.

An auxiliary braking system, such as an engine brake or hydraulic retarder, that slows the vehicle without using the service brakes. It prevents brake fade on long descents and is standard on heavy vehicles.

Loss of braking power caused by overheating of brake drums or discs during prolonged or repeated braking. Using a retarder and engine braking on long downhill sections prevents it.

A braking system that uses compressed air to apply the brakes, standard on heavy vehicles. It requires correct pressure to release the parking brake and to stop, so pressure warnings must be taken seriously.

The inspection a driver must carry out before the first journey of the day, covering brakes, lights, tyres, steering, mirrors, load security and warning systems. Defects must be recorded and fixed before driving.

The methods used to stop cargo moving or falling off, such as lashing straps, chains, blocking and headboards. It must withstand the forces of braking and cornering and be checked during the journey.

The maximum force a lashing strap or chain is permitted to transmit, marked on the equipment label. It is used with the weight of the load to calculate how many lashings are needed.

A number describing how much grip exists between the cargo and the load bed. It determines how much of the load's weight is already held by friction and how much must be secured by lashing.

The point where the vehicle's and load's weight is concentrated. A high or badly placed centre of gravity makes the vehicle unstable in curves and increases rollover risk, especially on tankers and tall trailers.

The danger of a vehicle tipping sideways, highest in curves, on ramps and with a high centre of gravity or an unsecured shifting load. Speed must be reduced before entering a curve, not during it.

The legal limits on a vehicle's length, width and height, and on the load it carries. Exceeding them requires a special permit and can make the vehicle illegal and dangerous on narrow roads.

A pilot car or escort required when a vehicle or load exceeds certain length, width or height limits. The escort warns other traffic and helps the driver pass obstacles safely.

The time a driver spends driving a heavy vehicle, recorded by the tachograph. It is limited per day and per week, and breaks must be taken before the limits are reached.

The uninterrupted rest a driver must take within each 24-hour period, normally at least 11 hours and reducible to 9 hours a limited number of times. It resets the driver's working day.

A longer rest taken after a week of work, normally at least 45 hours and reducible to 24 hours with compensation. It must be taken within each two-week period.

An on-board recording device that logs driving time, other work, availability and rest. Modern digital versions store data on a driver card and must be used correctly and protected from tampering.

A personal smart card inserted into the digital tachograph to identify the driver and record activity. It is personal, must not be used by anyone else and must be carried during the journey.

Transport documents describing the goods, sender, receiver and route. They must be carried on the vehicle and shown during checks, and they support the tachograph records.

The European agreement governing the transport of dangerous goods by road, covering packaging, labelling, documentation and driver training. Drivers need an ADR certificate and must follow the special rules for each class.

A reflective triangle placed behind a broken-down vehicle to warn other traffic. On a motorway it is placed well back, and the driver and passengers should wait in a safe place away from the carriageway.

Contacting the emergency services on 110 for fire, 112 for police or 113 for medical help. Give location, what happened and how many are injured, and stay on the line until told otherwise.

The immediate help given before emergency services arrive: securing the scene, checking breathing, stopping bleeding, keeping the injured warm and not moving casualties unnecessarily. It can save lives in the first minutes.

A portable device for putting out small fires, carried on heavy vehicles and checked for pressure and date. It is used only on small fires and only when escape remains possible.

A fire starting in the engine, brakes, tyres or load. The driver should stop safely, switch off the engine, get people away, call the fire service and only then attempt to fight a small fire.

Driving smoothly with early gear changes, steady speed, anticipation and minimal idling to cut fuel use and emissions. It also reduces wear on brakes and tyres and lowers accident risk.

Using the engine's resistance to slow the vehicle by releasing the accelerator in gear, instead of using the footbrake. It saves fuel and brake wear and improves control on descents.

Leaving the engine running while the vehicle is stationary. It wastes fuel, causes emissions and noise, and should be avoided except where the engine must run for safety or operation.

The licence class for driving heavy goods vehicles over 3.5 tonnes with a trailer up to 750 kg. It requires medical fitness, a theory test and a practical test, and periodic renewal.

Documentation showing a professional driver has completed the required basic and periodic training for commercial transport. It must be carried and renewed every five years.

The legal obligation to stop, help and identify yourself after being involved in a traffic accident, and to call emergency services when people are injured. Failing to do so is punishable.