Winter tire can deploy studs when it detects freezing road conditions

Temperature changing rubber pushing studs outwards that add grip as the tire cools, absolutely brilliant if the outer layers haven't been softened so far as to make the tire life impractical.

Upsides

- significant reduction in slide and sudden stop accidents

- significant drop in hydroplane events due to poor maintenance (the ride will be awful once the studs are exposed)

- possibly longer tire life

- incredible off road potential

- reduction in price of conventional full rubber tire

Downsides

- Increased road maintenance

- possibly decreased tire life

- increased pedestrian, consequential,and head on collision damage due to increased traction

- Decreased ride comfort as mass production will inevitably lead to increased tolerances

- which will also increase / complicate balance weighting which limits top speed rating