The technology, called Soak, changes colour if perspiration is high in salt, suggesting dehydration. Previous research by the European Hydration Institute and Loughborough University found that dehydrated drivers were as error-prone as those who had drunk alcohol. There are currently no plans to bring Soak into production. The sweat-sensitive coating, which was developed with Dutch design company Droog, is also applied to the steering wheel and changes it and the front seats from blue to yellow to signal dehydration. Prof Peter Wells, an expert in business and sustainability from Cardiff University Business School, said that measuring additional factors which impede drivers' abilities made as much sense as monitoring factors which affect the vehicle itself. "This is part of the overall idea that it's not just about monitoring the car but also the driver," he said.