Layer 1 - the frame tells you the job

Shape and colour come first. Before you even look at the symbol, the frame has told you whether the sign warns, commands, prohibits, reserves or informs.

Frame	Meaning
Red-bordered triangle	Warning: hazard ahead - slow down, be ready to act
Blue circle	Command: you MUST do what the symbol shows
Red-bordered circle	Prohibition: you MAY NOT
Blue square with R	Reservation: reserved for the symbol shown
Rectangle	Information or guidance
Yellow background	TEMPORARY (roadworks) version - same meaning, overrides the permanent sign

Three shapes to know on sight: octagon = stop / point-down triangle = yield / diamond = pedestrian priority.

Layer 2 - one symbol, five frames, five answers

The symbol is the subject, and it never changes meaning. Watch what the frame does to one bicycle:

Learn about 60 symbols + 6 frames instead of 500 signs. The wrong answers in the CLLT are built to catch picture-memorisers - "cyclists only" sits next to "cyclists prohibited" next to "cycle lane reserved". Decode the frame first and the answer chooses itself.

Layer 3 - the code confirms it

R1xx command / R2xx prohibition / R3xx reservation / W warnings / RM-WM-GM markings / IN information / T-prefix temporary / S signals.

Warning signs

Diamond or triangle, red border - a hazard ahead. Slow down and be ready to act.

Regulatory signs

Circles command or prohibit. Blue = you must. Red ring = you may not. The octagon STOP and point-down YIELD are regulatory royalty.

Information signs

Rectangles that inform - countdowns, cul-de-sacs, facilities.

Guidance signs

Green-background direction and exit signage on routes and freeways.

Road markings

The signs painted on the surface - lane lines, arrows, reserved-lane symbols.

Traffic signals

The S-series: standard robots, arrows, flashing railway reds and the pedal-cycle signal.