LK DMT Heavy Vehicle Written key terms

The maximum total weight of a vehicle including its chassis, body, fuel, load, and passengers as specified by the manufacturer. Exceeding GVW is illegal and unsafe.

The weight of the cargo or load a vehicle is designed to carry, calculated as GVW minus the vehicle's kerb weight. Overloading reduces braking and handling performance.

The total weight borne by a single axle or axle group, including the vehicle and its load. Exceeding axle load limits damages roads and increases tyre failure risk.

The arrangement of cargo so weight is spread evenly and safely across axles, keeping the centre of gravity low and within limits. Poor distribution causes instability and tyre overload.

The point where the total weight of a vehicle and its load is considered to act. A high centre of gravity increases rollover risk, especially on curves and during sudden manoeuvres.

The use of straps, chains, ropes, or other restraints to prevent cargo from shifting, sliding, or falling during transport. Proper securing protects other road users and prevents crashes.

A method of securing cargo using ropes, straps, or chains tensioned between anchor points on the vehicle and the load. Lashings must be rated for the load and regularly checked.

The complete set of equipment and methods used to secure a load, including straps, binders, anchor points, and load racks. It must meet legal standards and suit the cargo type.

A crash where a vehicle tips onto its side or roof, often caused by excessive speed in curves, sudden steering, or an unstable high load. Heavy vehicles are especially vulnerable due to high centre of gravity.

A dangerous condition where an articulated vehicle's trailer swings out of line with the tractor unit, often during braking on slippery surfaces or sudden steering. It can lead to loss of control and rollover.

A heavy vehicle combination consisting of a tractor unit and a semi-trailer connected by a fifth-wheel coupling. The joint allows turning but requires different handling techniques than rigid trucks.

A heavy vehicle with a fixed chassis and body that does not bend at a joint. It may tow a trailer but the main cargo area is integral to the vehicle.

A braking system that uses compressed air to apply brakes on heavy vehicles. It requires regular draining of moisture from tanks and awareness of brake fade and lag.

A temporary loss of braking power caused by overheating of brake components, often from prolonged or heavy braking on long descents. Drivers should use lower gears to reduce reliance on brakes.

A technique of slowing a vehicle by downshifting and letting the engine's compression resistance reduce speed, especially on long downhill grades. It helps prevent brake fade and overheating.

A systematic check of a heavy vehicle before driving, covering tyres, brakes, lights, fluids, load security, and couplings. It helps detect defects early and prevents breakdowns and crashes.

A quick visual and functional inspection of a vehicle conducted each day before use, checking tyres, lights, mirrors, load, and obvious leaks. It is a legal and safety responsibility of the driver.

The process of recording and reporting any vehicle fault or damage to the operator or maintenance staff so it can be repaired. Drivers must not operate a vehicle with a known serious defect.

The condition of a vehicle being safe and legal to drive on public roads, meeting standards for brakes, tyres, lights, steering, and emissions. Regular inspections and maintenance keep a vehicle roadworthy.

The depth of the grooves on a tyre, which affects grip and water dispersion. Heavy vehicles must meet minimum legal tread depths; worn tyres increase stopping distances and aquaplaning risk.

The amount of air inside a tyre, measured in psi or bar. Incorrect pressure causes uneven wear, poor handling, and increased fuel consumption; it should be checked when tyres are cold.

A loss of tyre contact with the road surface caused by a layer of water, leading to reduced steering and braking control. It is more likely with worn tyres and high speed in wet conditions.

A loss of traction where tyres slide instead of rolling, often on wet, icy, or loose surfaces or during harsh braking. Drivers should ease off pedals and steer gently to regain control.

The gap between your vehicle and the one ahead, which should increase with speed and load. Heavy vehicles need longer stopping distances, so a larger gap is essential for safety.

A guide for maintaining a safe following distance in good conditions by allowing at least two seconds between your vehicle and the one ahead. Increase to four seconds or more in poor weather or with heavy loads.

The total distance a vehicle travels from the moment a hazard is seen until it comes to a complete stop, including reaction distance and braking distance. It increases with speed, weight, and wet roads.

An area around a heavy vehicle that the driver cannot see directly or through mirrors. Drivers must check blind spots before turning or changing lanes, and other road users should avoid lingering there.

The routine use of rear-view and side mirrors to monitor traffic and surroundings. Heavy vehicle drivers must check mirrors frequently and adjust them properly before driving.

A quick glance over the shoulder to check the blind spot before changing lanes or turning. It complements mirror checks and is essential in heavy vehicles with large blind areas.

A driving style that anticipates hazards and assumes other road users may make mistakes. It involves keeping safe distances, scanning ahead, and being prepared to react calmly.

The ability to identify and predict dangerous situations on the road early enough to take safe action. It develops with experience and involves scanning, anticipation, and risk assessment.

The continuous visual search of the road environment ahead, to the sides, and behind, including mirrors and instruments. It helps drivers spot hazards early and maintain situational awareness.

A state of physical or mental tiredness that impairs alertness, reaction time, and judgment. Heavy vehicle drivers must manage rest breaks and avoid driving while fatigued.

A period of non-driving time taken to recover from fatigue during a journey. Legal rest break requirements exist for heavy vehicle drivers to ensure alertness and road safety.

The legal limits on driving time and required rest periods for commercial heavy vehicle drivers. They are designed to prevent fatigue-related crashes and are enforced by law.

A safety restraint fitted to vehicle seats that must be worn by the driver and passengers where provided. Wearing a seat belt significantly reduces injury risk in a crash.

A padded support at the top of a vehicle seat designed to reduce neck injury in a rear-end collision. It should be adjusted to the height of the occupant's head.

The primary legislation governing road traffic, vehicle registration, licensing, and driving offences in the relevant jurisdiction. It sets out legal duties and penalties for drivers.

An official document authorising a person to drive a specified class of vehicle on public roads. Heavy vehicle licences require additional tests and medical checks.

A record on a driving licence showing a conviction for a traffic offence or a restriction. Too many endorsements can lead to disqualification from driving.

A legal ban on driving for a specified period, imposed by a court or licensing authority for serious offences or accumulation of penalties. Driving while disqualified is a criminal offence.