Winter Tyres on Summer Roads: A Hidden Road Safety Risk

A new peer-reviewed study by researchers from VTI (Statens väg- och transportforskningsinstitut), Folksam and the Swedish Tyre Industry Information Council has found a significant association between the use of winter tyres in summer conditions and fatal grip-related traffic accidents.

A new peer-reviewed study by researchers from VTI, Folksam and the Swedish Tyre Industry Information Council has found a significant association between the use of winter tyres in summer conditions and fatal grip-related traffic accidents.

The researchers analysed 725 fatal passenger car accidents in Sweden between 2012 and 2021. While only around 7% of passenger cars are estimated to operate on winter tyres during summer, 22% of the vehicles involved in the fatal accidents studied had at least one winter tyre fitted.

Importantly, the increased risk remained even after accounting for factors such as vehicle age, Electronic Stability Control (ESC), and alcohol or drug impairment. The study also found that vehicles equipped with winter tyres were associated with a substantially higher risk of involvement in fatal grip-related accidents.

These findings build on years of controlled testing showing that winter tyres will deliver significantly longer braking distances and reduced grip on warm, wet and dry summer roads.

The Bigger Road Safety Message

While the study focuses specifically on the use of winter tyres during summer, its implications extend far beyond tyre choice alone.

Tyres are among the most safety-critical components on any vehicle. They determine how effectively a vehicle can brake, steer and maintain control. Yet tyre condition and compliance remain largely invisible in everyday traffic.

For decades, tyre safety has primarily been managed through periodic inspections and roadside spot checks. As a result, authorities, fleet operators and road owners have had limited access to real-world data about tyre conditions across the overall

The Swedish study highlights why that needs to change.

When researchers found that tyre-related grip performance, on vehicles fitted with winter tyres in summer, played a role in approximately one quarter of all fatal passenger car accidents studied, it reinforced the importance of understanding what is actually happening on the road, not just what is assumed to be happening.

From Spot Checks to Continuous Insight

At Roadguard, we believe that road safety improves significantly when tyre-related risks become measurable. By enabling automated tyre monitoring in live traffic, authorities, infrastructure owners and fleet operators can gain access to data that has traditionally been unavailable at scale. Better visibility enables earlier identification of risks, improved compliance, more informed maintenance decisions, and ultimately safer roads.

The broader lesson from this research is clear:

Tyres matter. Grip matters. Data enables improvement.

As transport systems become increasingly connected and data-driven, tyre safety deserves greater attention. The ability to understand tyre quality in real traffic, under all conditions, will become an important part of the next generation of road safety management.

Because road safety ultimately starts where every vehicle meets the road: the friction at the tyre-road interface.