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Front Brake Lights Could Drastically Diminish Road Accident Rates
(bioengineer.org)
This is a most excellent place for technology news and articles.
Not all of them. It is becoming more common, but for a while Hyundai and Kia didn't do this, and I know my older Ford doesn't.
Probably just in the US, since brake lights are only required when pressing the brake pedal. Mercedes illuminates them but then turns the brake lights off once the vehicle comes to a stop using regen.