system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why car's steering straighten itself after we let go?

When we are doing a u-turn, we don't really need to turn the steering back straight, because it will straighten itself automatically. 

Why?
gpt
It works all the time, even keeping the car stable on long since right aways.  It's call caster. The tire touches the ground behind the steering pivot point. The tire is pulled straight anytime there is forward movement.