Cat's eye (road)

The cat's eye is a safety device used in road construction and was the first of a range of raised pavement markers. It originated from the UK in 1933 and is used all over the world.

It consists (in its original form) of two pairs of reflective glass spheres set into a white rubber dome, mounted in a cast iron housing. This is the kind that marks the centre of the road, with one pair of cat's eye showing in each direction. A single-ended form has become widely used in other colours at road margins and as lane dividers. Cat's eyes are particularly valuable in fog and are remarkably resistant to snow plough damage.

A key feature of the cat's eye is the flexible rubber dome which is occasionally deformed by the passage of traffic. A fixed rubber wiper cleans the surface of the reflectors as they sink below the surface of the road (the base tends to hold water after a shower of rain, making this process even more efficient). The rubber dome is protected from impact damage by metal 'kerbs' - which also give tactile and audible feedback for wandering drivers.

The inventor of cat's eyes was Percy Shaw of Halifax, Yorkshire in England. When the tram-lines were removed in the nearby town of Bradford he realised that he'd been using the polished strips of steel to navigate. The name "cat's eye" comes from Shaw's inspiration for the device: 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 the items. The name Catseye was their trademark.