What are cats eyes?
Cat's eyes are reflective road studs that help drivers navigate roads, especially in at night or in foggy road conditions where visibility is low.
Embedded in the road surface, these small yet powerful devices reflect headlights of oncoming vehicles, guiding motorists and improving safety. They're typically found on motorways and other major roads.
The original cat's eyes were designed to replicate the glow from a real cat's eyes when reflecting light in the dark, which led to their iconic name. Today, they're a vital tool for road safety, helping reduce accidents by ensuring better visibility for drivers.
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When were cat's eyes invented?
Cat's eyes were invented in 1933 by Percy Shaw, a British engineer. Shaw got the idea for his invention while driving home on a foggy night. Struggling to see the road ahead, Shaw noticed his car’s headlights reflecting off the eyes of a stray cat sitting by the roadside.
Inspired by the way the cat's eyes reflected light in the dark, Shaw realised that a similar reflective device could help guide drivers at night or in bad weather. He patented his invention in 1934, and by 1937, cat's eyes were being installed on UK roads.
Shaw’s design was simple yet effective; using four glass beads, rubber moulding, and a cast iron base, cat's eyes were durable enough to withstand weather and vehicle weight while remaining highly reflective. This clever invention quickly became a staple on roads across the world.
How do cat's eyes work?
Cat's eyes work by reflecting a vehicle’s headlights, guiding drivers along the road. Each unit contains pairs of glass beads that face in opposite directions, ensuring that they reflect light regardless of which way traffic is moving.
These glass beads are housed in a rubber shell that compresses when a car drives over it, allowing the reflective surface to drop below the road and protect it from damage.
Another brilliant feature of cat's eyes is their ability to clean themselves. When a vehicle presses down on the device, the rubber mould compresses, and rainwater collected in the base is used to wash the reflective glass beads, keeping them clear and effective.
What colour are cat's eyes on the road?
One of the key features of cat’s eyes is the use of different colours to signal different parts of the road. Below is a quick reference guide for understanding the reflective studs on UK roads:
- White: Separates lanes or marks the middle of the road.
- Red: Marks the left edge of the road or motorway's hard shoulder.
- Amber: Shows the central reservation on dual carriageways or motorways.
- Green: Marks junctions, slip roads, or where access roads meet the main road.
- Green or Yellow: Temporarily mark lane changes during roadworks.
These colour-coded cat’s eyes are critical for road safety, providing clear guidance to drivers, particularly on fast-moving roads like motorways.
The impact of cat's eyes on road safety
From their various colours indicating different parts of the road to their self-cleaning mechanism, cat's eyes remain a crucial tool for keeping roads safe. Understanding their purpose and colour meanings can help drivers stay more aware and better informed while on the road.
For more helpful advice on navigating UK roads, visit our blog section, which is regularly updated with new insights and motoring information.