

The EU has approved G-triggered brake lights that do just that, flash rapidly on hard braking. I’ve only seen it on higher end cars so far, but they absolutely exist. Unfortunately in the US people stick brake flashers that blink in patterns every time they touch the brake. Mostly useless as they’re installed to be “look at me, aren’t I cool with my blinky brake lights?” rather than any additional safety.
Is it made of snails?
(/s, in case anyone wants to take that seriously)