[cgearhart]

RL is equivalent to optimal control in many real-world systems like robotics, self-driving vehicles, and other complex systems (aircraft control, etc.). There are lots of practical applications for RL, but it doesn't always work well; solving even simple problems can often be deceptively complex—to the point of being intractable, unstable, or both.

[bojanbabic]

to my knowledge, not a single self-driving car company is using RL in production. it is a more theoretic methodology than anything else.