Navigating a Safer Tomorrow: The future of Road Studs

Posted 30th November 2023

In 1934, the British engineer Percy Shaw made a remarkable observation: when light was directed towards a cat, its eyes reflected the light. During this era, when motor cars were still in their relative infancy, and driving at night was fraught with hazards, Shaw’s discovery sparked the beginnings of a revolutionary idea – reflective road studs could guide vehicles in the darkness.

These studs consisted of glass beads embedded in a rubber casing with reflective lenses and were vital for ensuring safety during the blackouts of the Second World War. In the eight decades that followed, technology has moved forward, allowing the design to adapt, the materials to change, and the way they work to fundamentally alter. In fact, the reflective studs that accompany us on trips along motorways, dual-carriageways, and other main roads continue to evolve, fuelled by innovation and safety initiatives.

We’ve written before about how reflective road studs – also known as ‘cat’s eyes’ – work. In this blog post, we want to show you how they might work in the future, including near-future ideas such as solar power and further ahead ones such as integration with autonomous vehicles and motion sensors.

Let’s begin with a quick road safety lesson.


What do the different colours of reflective road studs mean?

The UK is home to five separate colours of reflective road studs, all of which can – at different times – be seen on our motorways. Each one represents a simple message to drivers, highlighting transition points, borders and layout changes along the way.


White reflective road studs

These studs are strategically placed to delineate the edges of lanes or signify the centre of the road, providing a visual reference even in low-light conditions or inclement weather.


Red reflective road studs

Red studs can be found running along the left side of the road. These, often accompanied by physical rumble strips, prevent the driver from drifting into the hard shoulder or simply off the road.


Amber reflective road studs

You will find amber reflective studs running along the central reservation of a dual carriageway or a motorway, highlighting its presence and stopping the vehicle from unintentionally drifting towards it.


Green reflective road studs

While red studs do indeed mark the left-hand side of the road, green reflective studs are used to indicate the entrance and exit to lay-bys and slip roads, improving the safety of merging successfully.

Roadstuds layout on a motorway.
Roadstuds layout on a motorway.

Green/yellow reflective road studs

While the four previously mentioned colours are the most commonly encountered, green/yellow reflective road studs are deployed when a temporary adjustment to the road layout occurs. A scenario where they might be used would be long-term works that divert the traditional road.

Whatever the colour might be, laws exist which regulate the studs’ ability to withstand wet weather and extreme temperatures. The reflective road studs must also measure less than 20.3 mm in height and 130 mm in diameter. By fulfilling these criteria, the studs do not cause an obstruction but can enhance visibility.


What does the future of reflective road studs look like?

Reflective road studs in their current forms are excellent. They communicate a simple message universally understood by drivers and illuminate the route ahead. But could they be improved? Would modification of their technology, form or functionality improve the safety of our roads?

Can the rate of collisions be cut down with the implementation of futuristic reflective road studs? Many of the below ideas suggest the answer could be ‘yes’.


Solar-powered reflective road studs

Admittedly, we start our list of future road stud innovations with one that has existed for over 25 years, but it is included to differentiate between two different road stud concepts.

The first is passive road studs. These are the simple reflective studs invented by Percy Shaw in 1934 which have largely remained unchanged ever since. The second concept is the ‘active’ studs, whereby a stud functions independently from the presence of car headlights.

Instead, these active reflective road studs are lights with a power source that guide motorists along their route. In 1996 Clearview, under its former brand Astucia, developed solar-powered studs which harvested sunlight in the daytime and created its own illumination in the dark.

With the concept having existed for over 25 years, you might think the inclusion of solar-powered reflective road studs is a bit of a cop-out, but the concept is one not universally seen across the UK. As the technology becomes cheaper, it will be.

By using lights rather than reflective material, the studs can be customised, operated all night and day, and benefit road users who might not – for whatever reason – have the benefit of illuminating headlights.


Reflective road studs equipped with motion sensors

If Percy Shaw’s invention is considered to be the original reflective road stud and solar-powered LED lights are the 2.0 model, those equipped with motion sensors are the futuristic 3.0 version. At the very least, they are known in the industry as ‘intelligent road studs’, designed to detect the presence of vehicles, pedestrians, or other objects in their proximity.

The studs could, for example, detect a cyclist approaching a junction and begin a flashing sequence to alert drivers in the vicinity that there may be a hazard on the road. This feature would be particularly useful when cyclists are on the road at night without lights or reflectors of their own.

The most exciting part of this technology is that it’s far closer to being a reality than you might think. Hull City Council has embarked on a project – the first of its kind in the UK – to incorporate intelligent road studs into road planning measures in the city centre. Councillor Mark Ieronimo, Portfolio Holder for Transportation, Roads and Highways, said: “We hope that by making this area more appealing, it will encourage people to cycle and walk more.”

But it’s not just cyclists who benefit from reflective road studs equipped with motion sensors: the technology can provide valuable data regarding journey times that can then be displayed on digital signage to provide drivers with accurate information.


Reflective road studs integrated with autonomous vehicles

Right now, self-driving systems – such as those found in the Tesla Model S and the Mercedes EQS – are illegal on UK roads. However, once the government has put legislation into place that determines fault should things go wrong, these cars will likely become ubiquitous, part of the fabric of our vehicular life.

The smart computer systems with which these autonomous vehicles operate could, in theory, be synchronised with other intelligent systems, such as stud motion sensors. Having gathered data on traffic, the studs could influence routes to find quieter and quicker ways to the destination, cutting down on journey times and, thus, emissions too.


Eco-friendly materials used to manufacture reflective road studs

The road to sustainability and our willingness to contribute towards that journey wherever possible are both reflected in the manufacturing of road studs, whether passive, active, or intelligent. The studs themselves must be resistant to weather, impact and pressure applied by vehicles – large and small – so some materials would prove unsuitable. That being said, recycled plastic, bio-based composites, aluminium alloys, and even wood can all be utilised to ensure that the stud’s carbon footprint and resultant waste at the end of their life are both minimised.



The future is bright, illuminated by reflective road studs that could be equipped with solar-powered LED lights, motion sensors, and an ability to communicate with autonomous vehicles. Together, they light the way towards a safer, more integrated future, one that reduces avoidable congestion and improves collision rates on some of the fastest stretches of UK roads.

If you would like to know more about our reflective road stud service, speak to us today.



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