ALL UK drivers will be familiar with the little lights on the roads that guide our way as we drive.
But did you know that not only do they guide us, but the different colours also have different meanings? Read on to find out more.
There are five clear colours that are used to convey different messages to road users on their journey.
These five colours are: red, green, blue, white and amber.
The colours of the reflective studs serve a genuine purpose - and can really help you out when visibility is poor on unlit sections or in heavy fog.
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They've been around since the 1930s and the details of how they work are laid out in Rule 132 of the Highway Code.
The most common light drivers will see is the white light as these are used to mark the lanes of dual carriageways or motorways.
On a regular three-lane wide motorway you'll see two rows of these.
Amber cat's eyes appear on the far side of the road to mark the central reservation - and to stop you mindlessly changing lanes to the right.
By contrast, red lights denote the left edge of the road - before you hit barriers or drift onto the hard shoulder.
Green indicates a junction either joins or leaves a motorway, while blue is used for emergency services.
As well as the visual cue the lights provide drivers, the raised studs also help give drivers an audible and sensory reminder anytime they drift out of their lane.
Rumble strips are used alongside them to do the same.
Neil Greig, policy and research director at IAM RoadSmart, said: "Reflective road studs can be a lifesaver in fog and reduced visibility as they can give you vital extra information you might need in bad weather. Unfortunately, the most common studs we see are the yellow ones sprinkled all along the many roadworks on our motorways and A-roads.
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"They can change all the time so it’s important to stay alert and make sure you are following the right lane."
