Denmark Category C1/E Light Lorry Trailer Theory Test key terms

The combined actual weight of the lorry and its trailer, including all cargo, fuel, driver and passengers at any given moment. It must never exceed the maximum permitted train weight stated on the vehicle's registration documents.

The legal upper limit for how heavy a vehicle or vehicle combination may be, set by the manufacturer and approved in the registration. Exceeding it is an offence and affects braking, tyres and road wear.

The difference between the maximum permissible weight and the vehicle's unladen weight. It is the total weight of goods, equipment and persons the vehicle may legally carry, and it shrinks when heavy accessories are fitted.

The weight carried by a single axle or axle group, measured where the tyres touch the road. Each axle has its own permitted maximum, so a correctly loaded vehicle can still be overloaded on one axle.

The downward force a drawbar trailer exerts on the towing vehicle's coupling. It must stay within the coupling's rating: too little causes snaking, too much overloads the rear axle and lifts the front wheels.

The vertical load a semi-trailer transfers through its kingpin to the tractor unit's fifth wheel coupling. It must fall within the coupling's rated limit and is adjusted by sliding the trailer axles or the fifth wheel.

Placing cargo so that weight is spread correctly between axles and kept low and centred. Heavy items go over or ahead of the drive axles, and the load is secured so it cannot shift during braking or cornering.

The methods, such as straps, chains, nets and blocking, used to stop cargo moving relative to the vehicle. The required force depends on the load's weight and the direction of acceleration or braking.

The maximum force a strap, chain or other lashing may transmit in service, marked on the component. It is lower than the breaking strength and is the value used when calculating whether a load is sufficiently secured.

The initial tension applied to a lashing before the vehicle moves, created by a tensioner or ratchet. Adequate pre-tension keeps the lashing in contact with the load and prevents it loosening on rough roads.

The point where the vehicle's and cargo's weight effectively acts. A high or rearward centre of gravity makes the combination more prone to rollover and reduces steering grip on the front axle.

A side-to-side oscillation of the trailer that can grow until the driver loses control. It is provoked by excess speed downhill, too little nose weight, worn dampers or sudden steering, and is corrected by easing off the accelerator, not braking hard.

The danger that a high-sided lorry or trailer tips over in a bend or during a sudden swerve. It rises with speed, a high centre of gravity, soft road edges and an unsecured or shifting load.

The distance travelled from the moment the brakes are applied until the vehicle stops. It grows with the square of speed and is longer for a loaded combination, on wet roads and with worn tyres.

The distance covered while the driver perceives a hazard and moves the foot to the brake, before braking begins. It equals speed multiplied by reaction time and lengthens with fatigue, distraction, alcohol and darkness.

The sum of reaction distance and braking distance: the total distance needed to bring the vehicle to a halt from a given speed. It is the figure that matters when judging whether a gap is safe.

The gap kept to the vehicle ahead. A common rule is at least two seconds in good conditions, doubled or more in rain, darkness or with a heavy load, because the combination needs far more room to stop.

The area around a lorry and trailer that the driver cannot see in the mirrors. It is largest directly behind the trailer and along the right side, so cyclists and pedestrians there can disappear from view.

Setting the main and wide-angle mirrors so that the vehicle's sides, the trailer's corners and the road behind are visible. Correct adjustment before moving off is essential because a loaded trailer blocks the interior view.

The horseshoe-shaped plate on the tractor unit that locks onto the semi-trailer's kingpin. Before driving off, the driver must confirm the locking handle is secured and the tractor is raised slightly to test the coupling.

The vertical pin under the front of a semi-trailer that engages the fifth wheel coupling. It carries the trailer's pull and part of its weight, so its wear and locking are checked during the coupling test.

A trailer with a rigid drawbar that attaches to a hitch on the towing vehicle and steers by its own axle or axles. Its nose weight and coupling must match the towing vehicle's approval.

A trailer whose front rests on the tractor unit's fifth wheel and whose rear is carried by its own axles. It cannot stand alone without landing legs and is coupled and uncoupled in a fixed sequence.

A cable connecting the trailer's brakes or hitch to the towing vehicle so that, if the coupling separates, the trailer's brakes apply. It must be checked for damage and correct routing before every journey.

The walk-around inspection a driver performs before moving off: tyres, lights, coupling, brake lines, load securing, mirrors, fluids and the trailer's legs and cables. It prevents most preventable breakdowns and coupling failures.

The minimum legal groove depth, which for lorry tyres is 1.0 mm across the central three-quarters of the tread. Worn or unevenly worn tyres lengthen braking distance and increase aquaplaning risk in rain.

The compressed-air braking system used on lorries and heavy trailers, where pressure releases the brakes. A pressure loss triggers the warning buzzer and spring brakes apply automatically, so daily pressure checks are required.

An air-released, mechanically applied parking brake chamber on heavy vehicles. It engages automatically when air pressure falls, which is why a lorry cannot be towed or rolled until pressure is restored.

An engine or transmission braking device that slows the vehicle without using the service brakes, saving them from overheating on long descents. It is used together with a low gear and is often restricted in built-up areas.

Slowing the vehicle by releasing the accelerator in a low gear so the engine resists the wheels. On long downhill runs it prevents brake fade and helps keep a heavy combination stable.

The loss of braking power when brakes overheat, usually after repeated or prolonged use on a descent. The pedal feels soft or the vehicle pulls, and the remedy is prevention: lower gear, retarder and shorter brake applications.

When water on the road lifts the tyres off the surface and the vehicle loses grip and steering. Risk rises with speed, worn tyres and standing water, and the response is to ease off the accelerator and avoid sudden braking.

The EU rules limiting daily and weekly driving time and requiring minimum breaks and daily and weekly rest. They protect drivers from fatigue and are checked from the tachograph records by the authorities.

The recording device fitted to lorries that logs driving time, other work, availability and rest. Drivers must use it correctly, insert their card and be able to produce records for inspection at the roadside.

The personalised smart card inserted into the tachograph to identify the driver and record their activity. Using another driver's card or driving without one is a serious infringement with heavy penalties.

A record the driver adds to the tachograph for work, availability or rest that the device did not capture automatically, such as time spent on other duties. It must be made promptly and accurately.

The uninterrupted rest a driver must take within each 24-hour period, normally at least 11 hours, reducible to 9 hours a limited number of times. It may be taken in the vehicle if it has a suitable bunk.

The rule that after 4.5 hours of driving a driver must take a break of at least 45 minutes, which may be split into 15 and 30 minutes. The break is for rest only and cannot be spent working.

The transport document describing the goods, their quantity, sender and recipient. It must accompany the load and be available for inspection, together with any dangerous-goods or permit papers the journey requires.

A reflective triangle placed on the road behind a broken-down vehicle to warn approaching traffic. On motorways it is set well back and the driver and passengers wait behind the barrier, not in the vehicle.

A reflective garment that makes a person visible to traffic in poor light. It must be worn when leaving a vehicle stopped on the road or hard shoulder, and one should be within reach of the driver's seat.

Pulling onto the hard shoulder, switching on hazard lights, placing a warning triangle and moving everyone behind the barrier while calling for help. The hard shoulder is for emergencies only, never for rest or phone calls.

Driving smoothly with early gear changes, steady speed, anticipation and correct tyre pressure to cut fuel use and emissions. It also reduces wear on brakes and clutch and lowers the risk of collisions.

Leaving the engine running while the vehicle is stationary. It wastes fuel, increases emissions and noise, and should be avoided during loading, waiting and rest breaks by switching the engine off.

A system that holds a set speed without the accelerator being pressed. It saves fuel on flat roads but should not be used in heavy traffic, on slippery surfaces or on steep descents where engine braking is needed.

Tyres with a tread compound and pattern designed for cold weather, snow and ice. In Denmark they are not compulsory but are strongly advisable in winter, and their grip advantage fades on warm dry roads.

Metal chains fitted over the drive tyres to increase grip on packed snow and ice. They are used only where permitted and at low speed, and must be removed as soon as the road surface clears.

Driving in visibility reduced by fog, using dipped headlights and fog lamps correctly, reducing speed and increasing the gap ahead. Fog lamps must be switched off when visibility improves to avoid dazzling others.