Road traffic signs, road markings and signals
Signs, markings and signals is the visual-identification domain: you must read a sign's shape and colour, state what it requires, and interpret road markings and the signals of robots and traffic officers.
Shape and colour carry the meaning
- Octagon, red: STOP - stop completely behind the line.
- Inverted triangle: YIELD - slow down and give way; stop only if traffic requires it.
- Circle with red border: prohibition (no entry, no parking, speed limit).
- Blue circle: mandatory instruction, for example turn left only.
- Triangle with red border and yellow background: warning of a hazard ahead.
- Rectangle: information - blue for services, green for directions and distances.
Broken white centre line: you may cross to overtake when safe. Solid white on your side: do not cross. Double solid: neither direction may cross. Yellow line at the kerb: parking restriction. Zebra crossing: pedestrians on it have right of way. Box junction: enter only if your exit is clear.
Signals
Indicate in good time before turning or changing lanes and cancel afterwards. A traffic officer's signals override signs, markings and robots. An officer facing you with an arm raised means stop.
Worked example
You see a triangle with a red border showing a bend and the number 60. The triangle means warning, so a hazard - the bend - is ahead; 60 is an advisory speed, not a legal limit. The correct response is to reduce speed before the bend, not to hold 60 through it.
Traps
Confusing no entry (red circle, white bar) with no parking; ignoring a supplementary plate such as "100 m"; entering a box junction on a green light when the far side is blocked; obeying a green robot instead of a marshal's raised hand.