NZ Heavy Vehicle Theory Test key terms

A category of driver licence (Class 2 to Class 5) that authorises driving vehicles above the standard car weight and seat limits, with each class covering progressively larger combinations.

The entry heavy vehicle licence, allowing a driver to operate a rigid vehicle with a gross vehicle mass up to 18,000 kg, including a vehicle towing a light trailer.

A licence class permitting a rigid vehicle with gross vehicle mass over 18,000 kg, or a combination vehicle where the towed unit does not exceed 18,000 kg gross vehicle mass.

A licence class covering heavy combination vehicles where the towed unit has a gross vehicle mass above 18,000 kg, such as a truck and heavy trailer, but excluding very large articulated units.

The top heavy vehicle licence class, required for combination vehicles with a gross combined mass over 25,000 kg, including large semi-trailers and multi-unit heavy truck and trailer combinations.

A truck or bus whose chassis and load-carrying body form one unit that cannot articulate at a coupling point, though it may tow a separate trailer.

A heavy vehicle made up of a powered unit towing one or more trailers, joined by a coupling or fifth wheel so the units pivot relative to each other.

The maximum permitted total mass of a vehicle plus its load, as specified by the manufacturer and recorded on the vehicle's documentation and certificate of fitness.

The maximum permitted total mass of a towing vehicle together with all trailers and their loads, used to determine licence class and safe loading limits.

The portion of a vehicle's total weight carried by a single axle or axle set, which must stay within legal limits to protect roads and maintain stability.

A periodic inspection certificate confirming a heavy vehicle meets safety and equipment standards, required before the vehicle may legally be operated on the road.

A document or label specifying the maximum legal load and axle limits for a heavy vehicle, used to confirm the vehicle is being loaded within its permitted capacity.

A systematic check of tyres, brakes, lights, couplings, fluids and load security carried out by the driver before starting a journey to catch faults early.

A quick visual and functional inspection performed each day of use, covering tyres, wheels, lights, mirrors, couplings and obvious leaks or damage.

A check that the service brake and parking brake hold and stop the vehicle effectively, often performed at low speed or on a gradient before a trip.

A braking system that uses compressed air to apply the brakes, requiring adequate pressure build-up, leak checks and an understanding of low-pressure warnings.

The measured depth of grooves on a tyre, which must meet the legal minimum for heavy vehicles and be checked regularly to maintain grip and prevent blowouts.

The inflation level of each tyre, which must match the manufacturer's recommendation for the load carried and be checked cold to avoid uneven wear or failure.

The system of straps, chains, binders or curtains used to secure cargo so it cannot shift, fall off or affect vehicle stability during braking, cornering or sudden movement.

The overall condition of a load being correctly placed, distributed and restrained so the vehicle stays stable and the load cannot escape onto the road.

The point where a vehicle's weight is concentrated; a high or shifting centre of gravity increases rollover risk, especially on curves and in crosswinds.

A crash in which a vehicle tips onto its side or roof, often caused by excessive speed in a curve, sudden steering, overloading or a shifting high load.

The gap kept between your heavy vehicle and the vehicle ahead, which should be longer than for a car because of greater stopping distance and weight.

The total distance travelled from recognising a hazard to coming to a complete stop, combining reaction distance and braking distance, both increased by weight and speed.

Choosing and maintaining a speed appropriate to the road, weather, load and vehicle limits, including slowing before curves and descents rather than braking mid-corner.

A retarding device that uses engine compression to slow the vehicle on descents, reducing reliance on wheel brakes and helping prevent brake fade.

Loss of braking performance caused by overheating, common on long descents when wheel brakes are overused, managed by lower gears and engine braking.

An area around a heavy vehicle that the driver cannot see in mirrors, requiring careful mirror checks and awareness that other road users may be hidden there.

The large areas beside, in front of and behind a heavy vehicle where other drivers are difficult to see, so they should avoid lingering there.

The routine of scanning mirrors frequently and before any manoeuvre to monitor traffic, check blind spots and confirm the vehicle's position and load.

The sequence of mirror checks, indication, blind-spot check and smooth movement used before changing lanes, allowing extra time and space for a heavy vehicle.

Manoeuvring a heavy vehicle backwards, which requires checking behind, using mirrors and often a spotter, and keeping speed very low because visibility is limited.

A distance-based charge paid by owners of heavy vehicles and some light vehicles for using the road, purchased in advance as a licence and distance record.

A purchased entitlement showing the vehicle type, weight and distance band for which road user charges have been paid, which must be carried and kept current.

The displayed label showing the road user charges licence details and the distance covered, which must be affixed where it can be seen and replaced when renewed.

A meter fitted to a wheel hub that records distance travelled, used to calculate road user charges and confirm the licence distance has not been exceeded.

A record of driving hours, rest breaks, work time and distance, kept by drivers subject to work-time rules to show compliance with fatigue limits.

The cumulative hours a driver spends driving or performing other work, which must stay within legal limits and be balanced with adequate rest.

A defined period of non-work time that a driver must take between work periods to reduce fatigue and remain within legal work-time limits.

Physical and mental tiredness that slows reaction and judgement, managed by planned rest breaks, limits on work time and recognising early warning signs.