Ireland Bus Theory Test key terms

A recording device fitted to buses and trucks that logs driving time, other work, breaks, rest and availability, so that compliance with drivers' hours rules can be checked by enforcement officers.

The legal limits on how long a professional bus or truck driver may drive and work, and the required daily and weekly rest, designed to prevent fatigue-related collisions.

The minimum uninterrupted rest a driver must take within each 24-hour period, normally eleven consecutive hours, which may be reduced in limited circumstances under the hours rules.

A longer continuous rest that must be taken after a certain number of daily rests, normally at least 45 hours, which may be reduced with compensating rest taken later.

A paper disc inserted into an older tachograph on which driving, work, break and rest periods are traced, and which must be kept clean, unused and available for inspection.

A written or digital record a driver makes on a tachograph to account for time spent on other work, breaks or rest when the device was not recording automatically.

A personalised smart card issued to a driver that is inserted into a digital tachograph to identify the driver and store their activity data securely.

A breach of the legal driving, working or rest limits, such as exceeding daily driving time or failing to take a required break, which can lead to penalties and prosecution.

A period during which a driver performs no driving or other work and which counts towards the required interruption of driving under the hours rules.

Any duty a driver performs that is not driving, such as loading, vehicle checks or paperwork, and which must be recorded and counted within working time limits.

Carrying more weight or more passengers than the vehicle is legally permitted to carry, which affects braking, stability, tyre wear and can invalidate insurance.

The maximum total weight of a vehicle including its load, as specified by the manufacturer and recorded on the vehicle plate, which must never be exceeded.

The load carried by a single axle or axle group, which has its own legal limit separate from the overall vehicle weight and must be checked when loading.

The way weight is spread across a vehicle when loading, which should keep the centre of gravity low and balanced to maintain steering and braking stability.

The use of straps, restraints, curtains or other equipment to ensure that cargo cannot shift, fall from the vehicle or endanger other road users during the journey.

A systematic inspection carried out before driving, covering tyres, lights, brakes, fluids, mirrors and load, to confirm the vehicle is roadworthy and safe.

A routine visual inspection of the exterior and key controls of a bus or truck performed each day before use, looking for damage, leaks, tyre problems and faulty lamps.

The formal process of recording and reporting any fault found on a vehicle to the responsible person, ensuring it is repaired and not used if unsafe.

The condition of a vehicle being legally fit for use on public roads, with working brakes, steering, lights, tyres and bodywork free from dangerous defects.

The minimum legal depth of tread remaining on a tyre, which must be at least 1.6 millimetres across the central three-quarters of the tread for cars and similar vehicles.

The amount of air inside a tyre, which must be set to the manufacturer's recommendation when cold, as incorrect pressure affects grip, handling and fuel use.

A device fitted to buses and trucks that restricts the maximum speed the vehicle can reach, helping to reduce the severity of collisions and improve fuel efficiency.

The total distance a vehicle travels from the moment the driver realises the need to stop until it comes to rest, made up of thinking distance plus braking distance.

The distance a vehicle travels while the brakes are applied, which increases with speed, load, wet or icy roads and worn tyres or brakes.

A gap-keeping guide in dry conditions where a driver should stay at least two seconds behind the vehicle ahead, doubled to four seconds in wet weather.

An area around a bus or truck that the driver cannot see directly or through mirrors, where other road users may be hidden and at risk of collision.

A road user at greater risk of injury in a collision, such as pedestrians, cyclists, motorcyclists and children, who need extra care and space from large vehicles.

The safe lateral distance a driver should leave when passing a cyclist, which should be generous enough to allow for wobbles or sudden movements by the rider.

The routine use of interior and exterior mirrors before signalling, changing position or slowing, to identify vehicles and people in the blind spots around the vehicle.

The sequence of looking in mirrors, checking blind spots, deciding, signalling and then moving, which keeps other road users informed of a driver's intentions.

A controlled, maximum-effort braking action used to avoid an imminent collision, requiring firm pressure on the brake and keeping the vehicle straight.

Loss of grip between tyres and road surface, often caused by braking, steering or accelerating too harshly on wet, icy or loose surfaces, requiring gentle corrective action.

A loss of tyre contact with the road caused by water building up between the tyre and surface, leading to reduced steering and braking control in heavy rain.

Choosing and holding the correct lane on approach to and within a roundabout, signalling intentions clearly and giving way to traffic already circulating.

A junction marked with yellow cross-hatching that a driver must not enter unless the exit is clear, to prevent blocking cross traffic when queuing.

Coloured lights controlling traffic flow, where red means stop, amber means stop unless unsafe to do so, and green means proceed only if the way is clear.

A lane reserved for buses during specified hours, which other vehicles may only use when permitted by signs, and where stopping or parking rules also apply.