Road Signs and Road Markings
Reading the sign families
Irish warning signs are yellow diamonds with a black border and black symbol - not the red triangles used in the UK, which is the most common trap in this domain. Regulatory signs are circular: a red ring means a prohibition (speed limit, no entry, no overtaking, weight limit), while a blue circle gives a mandatory instruction (turn left, route for pedestrians, minimum speed). The stop sign is the only octagonal sign; the yield sign is an inverted triangle with a red border and white centre. Motorway signs are blue with white lettering, and information/directional signs are rectangular.
Markings that carry legal force
A continuous white centre line means do not cross it. A broken white line may be crossed to overtake when it is safe. Where there are double white lines and the line nearest you is continuous, you must not cross. A solid white stop line at a stop sign requires a full stop; a broken yield line requires you to give way.
Yellow lines at the kerb: a single yellow line restricts parking at the times shown on the nearby plate; double yellow lines mean no parking at any time. Yellow box junctions (cross-hatching) must not be entered unless your exit is clear - you may wait in one when turning right and blocked only by oncoming traffic. Hatched areas bordered by a continuous white line must not be entered.
Worked example
You are following a slow cyclist and the centre line ahead becomes continuous. You may not cross it to pass. Instead, hold back at a safe distance, keep left, and wait until the line breaks or the road widens - the marking, not the cyclist's speed, decides.