Cat's eye (road)

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For other meanings, see Cat's Eye.

A cat's eye is a safety device used in road construction in the United Kingdom. It usually has some form of a retroreflective mechanism such as paint or a plastic corner reflector (Originally, these were glass spheres about 1 cm in diameter in a brass holder) built into a sturdy housing, capable of surviving as vehicles pass over it. In places where roads are subject to snow, they must also survive being driven over by a snow plough. They are placed along road markings, as they serve to highlight these markings at night, fog, or low lighting conditions.

Cat's eyes were invented in 1933 by Percy Shaw of Yorkshire in England. The name "cat's eye" comes from Shaw's inspiration: the light reflecting from the eyes of a cat. In 1934, he patented his invention (patent No. 436,290 and 457,536), and on March 15, 1935, founded Reflecting Roadstuds Limited in Halifax to manufacture cat's eyesTemplate:Ref. A key feature of the cat's eyes was being fixed into a flexible rubber dome support which buckled under the weight of vehicles, allowing the cat's eyes to sink below the road surface. A fixed rubber wiper passed over the front surface of the reflector as it sank below the surface of the road, thus cleaning the reflector. Other reflectors that did not have this feature rapidly lost their effectiveness as they became dirty.

They became popular in Britain during World War II, in the era of blackouts. The Government realised that drivers needed to see where they were going, even in the midst of a blackout. Cat's eyes use a system where the light is reflected from the car's headlights, thus allowing a limited amount of light. There are now some self-illuminated versions, either wired to a power supply or using solar power. These increase visibility range. An additional benefit of cat's eyes is the characteristic thunk sound made when driving over the device, warning a driver that they have started to leave their lane.

James May, co-presenter on the UK TV automobile show Top Gear had this to say about the Catseye: "The Catseye is what great design is all about. Simple, functional, and beautiful. And on top of that, this little block of iron and rubber has probably done more to save lives on the road than anything since.".

1 Local practice
- 1.1 United Kingdom
- 1.2 Republic of Ireland
2 References
3 See also
4 External links

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Local practice

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United Kingdom

Image:Catseye closeup.jpg

Various types of cat's eye exist. In Britain, white cat's eyes are used for the centre of a road, lane markings, or soft traffic islands. Red cat's eyes are placed along the hard shoulder of a motorway, and orange cat's eyes are placed along the edge of the central reservation. Green cat's eyes denote joining or leaving slip roads at junctions, and blue cat's eyes are used for police slip roads.

Most permanent cat's eyes have two reflectors at each end and retract into a housing when driven over — the lenses are cleaned against a rubber scraper as they move, thus ensuring they are visible. As these units are not very visible in daylight they are generally used in conjunction with traditionally painted lines. Temporary cats eyes with just a reflective strip are often used during motorway repair work and as these are easily visible in daylight as well as in darkness they can be used on their own for lane division.

Also seen during motorway repair work are traffic cones that are inserted into the socket of a retractable cats eye rather than being free-standing. These are often used in conjunction with two rows of the temporary cat’s eyes to divide traffic moving in opposite directions during motorway roadworks.

The cats eye reached the top ten in the Great British design quest along with the video game Tomb Raider, and the Supermarine Spitfire (a WW2 fighter plane) run by the BBC television programme The Culture Show.

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Republic of Ireland

In the Republic of Ireland, usage is similar, but yellow cat's eyes are used on all hard shoulders, including motorways (red cat's eyes are not used, nor are blue). In addition, standalone retroreflector batons are often used on the verge of Irish roads.

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