On a foggy night in Yorkshire 85 years ago, Percy Shaw was driving home near his native Boothtown, near Halifax. Usually in fog he could follow the tramlines in the road shining in the reflection of his car headlights, but that night in December 1933 the tramlines had been taken up for repairs and Percy almost veered off the road.
Suddenly a pair of bright cat’s eyes stared at him in his headlights. It was a Eureka moment. Percy realised that reflectors in the road could guide drivers at night, whatever the weather. The following year he patented the cat’s eye, using glass bead reflectors wrapped in a rubber casing and iron box embedded in the road.
When a vehicle drove over the reflector, the rubber and glass beads were pushed down below the road surface, and it was self-cleaning – the iron shoe filled with rainwater and pushing the top down made the rubber squirt water and clean the cat’s eye.
Cat’s eyes became important during the second world war, in the blackout when streetlights were turned off and car headlights were limited, to frustrate German bombers. The reflectors proved so successful that after the war the junior transport minister Jim Callaghan introduced them across Britain’s road network.
