The "on demand" chains of Kia and Hyundai

In this video we see how the "on demand" chains of Kia and Hyundai work: these brands have developed an innovative technology that allows for snow chains to be integrated directly into the tires; this solution is based on the use of shape memory alloys. In practice, there are modules inside the wheel made of alloy with memory effect. When driving in normal conditions, they remain compressed and do not come into contact with the road surface, but in case of snow or ice, it is possible to activate the snow chains by simply pressing a button: at this point the alloy modules expand and protrude from the tire surface, ensuring grip and safety on the road surface. This technology offers the advantage that it is no longer necessary to mount and dismount the chains, still ensuring the stability of the vehicle on the road. However, there are also many doubts: one would travel all the time with a summer tire, losing the performance and safety of winter tires; it is still unclear how the normal wear of the tread would be managed, with the modules coming very close to the asphalt even when the "snow chain" mode is not activated. The costs of this are known, but they are thought to be rather high, given the complexity of the integrated system, which involves the car, wheels, and tires.