The History, Invention & Function of Cats Eyes (Road Studs)

What are Cats Eyes (Road Studs)?

Cats Eyes, also called Road Studs, are a reflective safety device. They’re used to mark the road to make it easier to see whilst driving.

There are many colours which each have a different meaning. Find out how a near accident in Halifax led to one of the most famous road safety features in the world.

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How were Cats Eyes (Road Studs) invented?

In 1890, Percy Shaw was born at Lee Mount in Halifax. He was the fourth child and the second son of James Shaw and Esther Hannah Morrell.

Esther was James’ second wife. As a result, Percy also had seven half brothers and sisters from his father’s first marriage.

The family continued to expand. When Percy was just two years old, they decided to move to Boothtown Mansion.

Percy, along with his siblings, financially supported their father’s £1 wage. They joined together to grow and sell the vegetables from their garden.


Percy left school when he was 13 years old. He soon found work as a labourer at a cloth mill where he carried bobbins of wool from the winders to the weavers.

Despite having a job, Percy wanted to continue with his learning. This led to him learning book-keeping at night school which resulted in Percy taking a job as a book-keeper.

Later on, Percy found an apprenticeship with a wire drawer. He didn’t like the low wages so often took on many unskilled engineering jobs instead.

In the 1930’s tragedy struck the family. Percy’s parents died and left him along with his oldest unmarried sister to run their household.

As a way of earning more money, Percy began making a living laying tarmac paths and drives. He owned his own business and had several employees.

This point in his story becomes unclear. There are several versions of how he came to invent cats eyes (road studs) so we’ve picked the top three.

The first version is arguably the most famous. It’s said that Percy was driving through Clayton Heights from the Old Dolphin at Ambler Thorn towards his home in Halifax.

As he was driving along a long bend, he noticed a cat sitting on a fence. When his headlights shone on the cat, the cat’s eyes reflected the lights back at him.

This cat supposedly saved him. If it hadn’t been there, he would have veered off the road and down the steep drop below.

The second version originates from an interview with Alan Whicker. Percy said that on a foggy night he wondered if he could move the reflective studs from street signs to the road surface.

The final version was often told to the children who visited the factory in the 1970’s. Percy said drivers used the reflective surface of tramlines to follow the road on dark or foggy nights.

It was in 1933 that Percy Shaw invented these reflective road studs. He decided to call them ‘Cat’s Eyes’.

In 1934, Percy decided to patent the design that he’d created. The following year, he formed the company Reflective Roadstuds Limited in his home town of Halifax.

How are Cats Eyes (Road Studs) used today

After the first original design was created, they started being laid at busy crossroads. These were BradfordWakefield, and Halifax-Leeds Road and Drighlington.

Soon after, a problem was found with the design. A few days of rain and mud had obscured the glass reflectors and drivers could no longer see them.

As a result, Percy got to work. He found a way to adapt his designs in order to resolve this issue.

When vehicles passed over the rubber mounting, they would depress and therefore clean the beads. This was effective when the metal housing filled with water.

Originally. all of the parts were manufactured elsewhere. However they were brought to the factory Percy owned and put together.

In 1939, the company decided to change the way they operated and ran. As a result, they chose to produce everything themselves.

During World War II, the business came across its big break. A national blackout during this time made road studs a necessity in order to keep people safe.

In the 1960’s, Cat’s Eyes were being shipped across the world. Percy Shaw became known as the man behind this new motoring innovation.

In return, this led him to receive an OBE in 1965. Eleven years later, Percy died aged 86.

At the business’s peak, the factory had employed around 130 people. Each year they were producing over a million road studs.

The factory is still located at the same site in Boothtown, Halifax. However, since then, the workforce has been reduced.

Percy Shaw has saved and continues to save thousands of lives across the world. Just goes to show what the inventiveness and grit of a Yorkshireman can achieve.

What do the different colours of Cats Eyes (Road Studs) mean?

In total, there are 5 different colours of Cats Eyes that can be found on the road. Each of these have a different meaning and are designed to keep drivers safe.

The colours and meaning of Cats Eyes (Road Studs) are:

  • White – marks the middle of the road
  • Red – warns drivers where left edge of the road is
  • Amber – this marks the central reservation of a dual carriageway or motorway
  • Green – marks the edge of the main carriageway at lay-bys and slip roads
  • Green/yellow – this means that there are temporary adjustments happening to the road layout