system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are curved stretches of highway tilted?
gpt
This is called banking, and it's done to prevent cars from sliding off the road at high speeds.


When you're driving in a straight line, all the energy of the vehicle is aligned with the direction of travel. If you were to slam on the brakes, you'd decelerate in a straight line.

However, when you're going around a curve, your energy becomes compound. It's not just in a straight line in front of you, but also away from the center of the curve. If you were going around a curve, and the road suddenly turned to ice, you'd continue moving forward, but also *outward* along the radius of the curve.

The banking is done to offset this outward energy and help cars stay on the road - without the banking, taking even a large turn will run the risk of the vehicle sliding left or right, since the amount of friction between the road and the tires is finite, and can be overwhelmed by sufficient speeds.