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Road studs – also known as cat’s eyes – are small elevations found on streets around the world that serve to demarcate traffic lanes and foster safe driving. Originally fitted with reflective spheres lit by vehicle lights, road studs have increasingly been upgraded with LED lights in recent years to enhance their visibility, especially in areas with increased risk of accidents such as unlit country roads.
Taking the concept further, the EU-funded project INROADS added integrated communication and sensor systems – powered by renewable energy – to make these LED road studs smarter.
“We wanted to understand the range of uses of intelligent road studs,” says project coordinator Martin Greene of the Transport Research Laboratory (TRL Limited) in the United Kingdom. “For example, could we put them into a low power mode, only illuminating them when traffic approached to save money and CO2 emissions due to reduced energy use?”
Better behaviour behind the wheel
Once the intelligent roads studs had been designed and tested in the laboratory, it was time to try them out in the real world.
Field-testing focused on active lane marking applications and was carried out at test facilities in Spain and Austria. Live road testing was performed on the A6 autobahn between Vienna and the Slovak capital of Bratislava and in Israel on a disused service road east of Tel Aviv.
“We chose to focus on the most technically challenging potential applications,” says Greene. "It was also important to design road studs to be compatible with current traffic management systems and to use current communication standards."
At project partner IFSTTAR's facility in Paris, volunteers were tested on driving simulators where their behaviour and attention levels were monitored. They were given three different driving scenarios which simulated driving on a curved road in different conditions; an unlit road lit by headlights, a road with standard street lights and a section illuminated using active road studs.
“The results of simulations were extremely encouraging,” says Greene. “Drivers performed better and kept to their lanes when guided by intelligent road studs – they even reduced their speed compared with driving with only headlights or street lights.”
A comprehensive study of the project into the costs and benefits of intelligent road studs showed clear potential regarding safety, cost and carbon emission reductions. Another major INROADS outcome was a study of how drivers would act and think when guided by intelligent road studs. This analysis confirmed that drivers reacted favourably to intelligent road studs by decreasing their speed before, during and after driving around dangerous curves.
Future uses
INROADS found much potential in further developing smart road studs. The project confirmed that smart road studs communicating with a central traffic management could react to their environment. Intelligent road studs could also be used over a wide area to communicate changing road conditions to drivers and alert them in advance about possible dangers ahead. And by using renewable energy, they could provide a cheaper and safer alternative to traditional street lighting on rural roads.
INROAD’s technology is already being recognised, with project coordinator TRL being awarded a contract from Transport for London – the UK capital’s local transportation system authority – to undertake a simulator study for a variable use transport lane based on smart LED technology. And while the system is not yet ready for production, the technology continues to be optimised and developed further to meet commercial standards.