Explanation: Reflective studs are used to help you in poor visibility. Different colours are used so that you'll know which lane you're in. These are
- red on the left-hand edge of the carriageway
- white between lanes
- amber on the right-hand edge of the carriageway
- green between the carriageway and slip roads.
Category: Vehicle handling
References: The Official DVSA Guide to Driving: Section 11, Highway Code: Rule 132