Ireland DTT Car key terms

The priority one road user has over another at a junction, crossing or narrowing, usually shown by signs, markings, or the default rules rather than by asserting yourself.

To slow or stop and let other traffic pass before you proceed, as required at a yield line or when joining a major road from a minor one.

The road that has priority at a junction, normally indicated by a continuous centre line or a warning sign on the approach from the minor road.

A road that meets or crosses a road with priority, where drivers must normally yield to traffic on the major road before entering or crossing it.

A junction area marked with yellow cross-hatching that you must not enter unless you can clear it, or unless you are turning right and only oncoming traffic blocks you.

A solid white line across your lane at a junction or sign where you must come to a complete stop and check that it is safe before moving off.

A broken white line across your lane, often with a yield sign, meaning you must slow down, check for traffic and give way before entering the major road.

A solid centre line that you must not cross, except to avoid an obstruction or to enter a premises or side road where it is safe to do so.

A dashed centre line separating traffic or lanes; you may cross it to overtake or change lane when it is safe and legal to do so.

Painted lines, arrows, hatched areas and words on the road surface that guide, warn and regulate drivers, and which have the same force as signs.

The cross-hatched yellow area inside a box junction, which you should only enter if your exit is clear, to avoid blocking cross traffic.

Entering a junction or crossing when traffic ahead prevents you from clearing it, so that you obstruct other road users, which is a common cause of gridlock.

Passing another road user travelling in the same direction, allowed only when it is safe, legal and you can see far enough ahead to complete the manoeuvre.

Enough clear road and sight line ahead to pass, return to your lane and still leave a safe gap before any oncoming traffic or hazard arrives.

The gap between you and the vehicle ahead, which should normally be at least two seconds in dry conditions and longer in rain, fog or darkness.

A method of checking your gap by counting two seconds between the vehicle ahead passing a fixed point and you reaching the same point.

The total distance needed to stop, made up of thinking distance while you react plus braking distance once the brakes are applied.

Driving too close behind another vehicle, reducing your time to react and intimidating the driver ahead; it is a major cause of rear-end collisions.

The area around your vehicle that mirrors do not show, where another road user can be hidden; always check over your shoulder before moving off or changing lane.

The habit of checking mirrors and then turning your head to check the blind spot before any manoeuvre such as pulling out, turning or overtaking.

Moving from one marked lane to another, which requires mirror and blind-spot checks, signalling in good time and ensuring the new lane is clear.

Using your vehicle's direction indicators to warn other road users of your intention to turn or change lane, giving clear and timely notice.

A circular junction where traffic normally travels anti-clockwise in Ireland and gives way to traffic already on the roundabout coming from the right.

Signal-controlled junctions and crossings where red means stop, amber means stop unless it is unsafe to do so, and green means proceed if the way is clear.

The traffic light phase after green; you must stop unless you are so close that stopping would be unsafe, and it never means speed up.

A marked crossing where pedestrians have priority once they have started to cross; drivers must slow down and be ready to stop.

A crossing marked by black and white stripes where pedestrians have right of way; you must stop for anyone waiting or already crossing.

Road users at greater risk in a collision, such as pedestrians, cyclists, motorcyclists, children and older people, who need extra time and space.

A lane marked for cyclists, which drivers should not enter and must check before turning across, as cyclists may be hidden alongside.

The maximum legal speed on a road, shown on signs; the limit is a ceiling, not a target, and you must drive slower when conditions demand.

The default limit of 50 km/h in built-up areas unless signs show otherwise, applying to towns and cities where pedestrians and cyclists are present.

A sign showing the maximum speed permitted on that stretch of road, which overrides the default limit for the type of road.

A sign, usually with a red-bordered triangle in Ireland, that alerts you to a hazard ahead such as a bend, junction, school or uneven road.

A sign that imposes a legal requirement or prohibition, such as a stop sign, yield sign or speed limit, which must be obeyed.

A speed below the limit that matches visibility, weather, traffic and road surface, so you can stop within the distance you can see to be clear.

The longer braking distance needed on a wet surface, where grip is reduced; allow more space and brake earlier and more gently.

Loss of grip when a layer of water lifts the tyres off the road, causing steering and braking to feel light; ease off the accelerator and avoid harsh braking.

The depth of the grooves on a tyre; the legal minimum for cars in Ireland is 1.6 mm across the central three-quarters around the whole circumference.

The air pressure inside a tyre, which should be checked regularly when cold and set to the manufacturer's figures for the load being carried.

A quick routine inspection before driving covering tyres, lights, fluids, mirrors, wipers and load security to catch problems before they become dangerous.

The condition of a vehicle in terms of its tyres, brakes, lights, steering and bodywork, which must be safe and legal to drive on public roads.

The compulsory periodic roadworthiness test for cars in Ireland, required at set ages and intervals, checking safety and emissions items.

Using headlights, dipped beams and fog lights correctly, and keeping windscreen, mirrors and wipers clear so you can see and be seen.

Rear or front lamps for use only in seriously reduced visibility such as fog or heavy rain; switch them off when visibility improves to avoid dazzling others.

Tiredness that slows reactions and judgement; the only real remedy is to stop somewhere safe and rest, not to open a window or turn up music.

Driving after drinking, which is illegal above the legal limits and impairs judgement, reaction time and risk-taking even below them.

Anything that takes your attention from the road, such as a phone, sat-nav, food or passengers; even a brief glance away can be dangerous.

Using a hand-held phone while driving is illegal; even hands-free calls distract, so set up devices before you move off.

Actively scanning ahead, to the sides and behind, using mirrors and looking well up the road so you spot hazards early and can react in time.

The skill of spotting developing risks, such as a child near a parked car or a car edging out, early enough to slow or stop safely.

Points added to your licence for certain driving offences; accumulating them leads to disqualification, and they stay on record for a set period.

Pollutants and greenhouse gases from a vehicle's exhaust; smoother driving, correct tyre pressure and avoiding unnecessary idling reduce them.

Driving smoothly with early gear changes, steady speed, anticipation and no unnecessary idling to cut fuel use and emissions.