Road Signs, Markings and Traffic Control Devices
Reading signs by shape and colour
Shape and colour carry meaning before you read the words. A red circle with a slash is a prohibition. A red triangle warns of a hazard ahead. A yellow diamond also warns, often of a temporary or changed condition. A green rectangle gives direction and distance information. A blue or white rectangle with a symbol gives a regulation or permission, such as a parking or transit lane rule. A yellow sign with black text is generally a warning of a changed traffic condition.
Markings that decide questions
A solid centre line means do not cross. A broken centre line may be crossed to overtake when safe. Double lines with one solid and one broken mean the driver on the broken side may cross. An edge line marks the road edge; a wide painted island or chevron area should not be driven on. A painted yellow line at the kerb means no stopping. A broken white lane line may be crossed to change lanes; a solid white line should not be. Bike lanes and bus lanes are marked and carry their own rules.
Common traps
- Mixing up 'no stopping' (yellow kerb line) with 'no parking' (a sign allowing brief stops).
- Assuming a warning sign sets a speed limit; it does not.
- Treating a school zone sign as applying all day, when it applies only during the posted times.
- Missing a supplementary plate under a sign that changes when or to whom it applies.
Worked example
A sign shows a red circle, a black 'P' and a crossed-out symbol with a plate reading '8.30 am - 5 pm Mon-Fri'. Outside those times the restriction does not apply, so the general parking rules govern.
Rule of thumb
Read every sign top to bottom, including the plate underneath, and check the times before answering.