Motorway Reflective Stud Colours Explained
Motorway Reflective Road Studs
Motorway Reflective road studs, often called 'Cat's Eyes,' are a vital safety feature that provides drivers with crucial guidance, especially during darkness or poor visibility. A color-coded system is used to convey specific information about the road layout.
White studs are the most common and mark the lanes or the center line of the road, separating traffic streams moving in the same or opposite directions.
At the edges of the main carriageway, red studs are used to delineate the left-hand edge and the boundary with the hard shoulder or verge.
Conversely, amber/yellow studs mark the right-hand edge, often found along the central reservation of a dual carriageway or motorway. For junctions and exit/entry points, green studs indicate the edges of slip roads and lay-bys.
Finally, fluorescent green/yellow studs are used temporarily to denote adjustments to the lane layout, typically in areas where roadworks are taking place, helping drivers safely navigate changes
Introduction to Motorway Studs
Introduction to Motorway Studs
When you’re cruising along a motorway—especially at night or during heavy rain—it’s the small things like motorway studs and their colours that silently keep you safe. These tiny reflective markers, often called “cat’s eyes,” help drivers stay in their lanes, judge road layouts, and make well-informed decisions during challenging driving conditions.
Motorway studs play a huge role in road safety, and knowing what each colour means can make your journey smoother and safer.
What Are Motorway Studs?
What Are Motorway Studs?
Motorway studs are raised or embedded reflective devices placed between lane markings. They bounce light back to the driver, helping them see the road layout even when visibility is poor.
You’ll see them on:
Major motorways
Dual carriageways
A-roads
Slip roads
Temporary diversion routes
They’re especially helpful at night, in fog, heavy rain, or on unfamiliar routes.
Why Colour-Coded Studs Matter
Why Colour-Coded Studs Matter
Each stud colour gives drivers a message. Understanding these colours helps you:
Stay in the correct lane
Avoid drifting into restricted areas
Recognize junctions and exits early
Respond quickly during poor visibility
Motorway studs and their colours are essential for safe, confident driving.
The Meaning Behind Motorway Stud Colours
The Meaning Behind Motorway Stud Colours
Understanding motorway stud colours is simple once you know the rules. Every colour has a specific purpose that improves safety and navigation.
White Studs: Standard Lane Markers
White studs are the most common. They indicate the lanes on the carriageway and separate:
Individual traffic lanes
Edge of the main carriageway (in some sections)
You’ll follow these most of the time while driving.
Red Studs: Hard Shoulder Boundary
Red Studs: Hard Shoulder Boundary
Red studs mark the left-hand edge of the motorway, showing the boundary with the hard shoulder.
They’re a warning that:
You must stay out of the shoulder
It's for emergencies only (unless signs say otherwise)
Seeing red studs on your right means you’ve drifted!
Amber Studs: Central Reservation
Amber studs run along the right-hand side of the carriageway, separating the motorway lanes from the central reservation.
They help drivers:
Stay safely away from the median
Know when they’re too close to the central barrier
Green Studs: Exits, Slip Roads & Lay-Bys
Green Studs: Exits, Slip Roads & Lay-Bys
Green studs highlight the entry and exit points, such as:
Slip roads
Lay-bys
Emergency refuge areas
Bifurcation lanes
If you see green studs, it often means an exit or joining point is ahead.
Green/Yellow Studs: Temporary Road Works
These two-tone studs guide drivers through road works or temporary diversions.
They are:
Bright
Highly visible
Used to replace standard studs temporarily
These studs help keep drivers safe in fast-changing environments.
How Motorway Studs Improve Road Safety
How Motorway Studs Improve Road Safety
Motorway studs help reduce accidents by:
Providing clear lane guidance
Enhancing visibility during bad weather
Preventing drivers from drifting across lanes
Alerting drivers to upcoming exits or restricted areas
Research shows they can reduce nighttime accident rates significantly because they improve reaction time and visual clarity.