Cornering speed is a critical safety factor. The speed limit for cornering cannot be established in the abstract; rather, it depends on several elements, including the curve radius, the friction coefficient between tires and road, and road surface conditions.
Excessive cornering speed can lead to understeer: the vehicle steers less than necessary and widens the trajectory set by the driver with the front end. Instead of turning, the vehicle continues straight.
Let's consider the first factor, the curve radius. Not only the maximum traversable speed but also the safest trajectory depend on the radius. The Nardò Ring is considered the fastest circular test track in the world; thanks to its 4 km diameter, it is possible to reach speeds exceeding 300 km/h while driving on it. How is this possible? Centrifugal force – which pushes the vehicle toward the outside of the set trajectory – is inversely proportional to the curve radius, therefore: the larger the curve radius, the smaller the effect of centrifugal force. On a wide curve, we can stay on track even at a slightly higher speed.
Speed affects the intensity of centrifugal force: the centrifugal force acting in a curve is proportional to the square of the speed. In simple words: if speed doubles, centrifugal force increases fourfold!
