Swedish Scientists Find Way to Make Winter Tires 20% Safer for Roads and Health

Scientists from the Royal Institute of Technology in Stockholm have conducted a study with potentially groundbreaking implications for winter road safety. Their research suggests that using an alternative hard metal instead of cobalt in winter tire studs could reduce both road wear and the amount of hazardous particles in the air by 20%.

The researchers compared the wear on asphalt and particle emissions caused by studs containing cobalt with those made from an alternative iron- and nickel-based metal. The results showed that the new material provides equally good grip on ice and packed snow, but causes significantly less damage to road surfaces.

Professor Ulf Olofsson from the Department of Engineering Design explained that cobalt, widely used in stud production, is a cost-effective solution. Its extreme hardness and resistance to wear make it a popular material for drilling tools. However, when it comes to asphalt, cobalt studs literally grind it into particles that, when inhaled, penetrate deep into the human body.

According to Olofsson, for safe driving on ice, studs should be only 20%-30% harder than asphalt. However, the studs currently on the market are twice as hard as the road material and nine times harder than ice at -40°C. "This is excessive," the professor emphasized.

The research group is currently studying the durability of alternative stud materials, which is the next step in finding a replacement for cobalt-containing studs.

Although studies show that studded tires save about 70 lives annually in Sweden, some cities in the country have banned their use on certain roads due to the health risks associated with asphalt particles in the air. In most US states, the use of studded tires is restricted, and in some, completely prohibited. In Europe, studded tires are mostly allowed, but banned in several countries, including Germany, the Netherlands, and Poland.

Olofsson noted that in the EU, particle emissions from tire, road, and brake wear are equivalent to exhaust emissions in terms of PM10 (particles with an aerodynamic diameter of less than 10 μm). However, in Northern European countries, PM10 emissions from non-vehicle sources significantly exceed exhaust emissions due to the frequent use of studded tires.

The use of studded tires also increases road maintenance costs. Olofsson estimates that the lifespan of road surfaces in Sweden is half that of Germany, where there is a ban on studded tires.

This research opens up new perspectives for improving road safety in winter while reducing the negative impact on the environment and human health. The use of alternative materials for studs could be an important step in solving the problem of air pollution and premature road wear, especially in countries with harsh winter conditions.