I don't know what the system is called but it's been around on a lot of cars for a while now. Our car does it (2016 Nissan Qashqai) - the hazards came on automatically when I had to brake hard on the motorway, and everyone else's hazards came on too - it was exactly the reason I knew how I knew I had to instantly brake hard due to all the cars ahead hazard lights coming on with the brake lights.

It's a fact.

I'm a truck driver in Germany, and even my Volvo truck turns the hazards on under hard braking.

In Europe it is required for vehicles decelerating faster than 6m/s^2^ and I believe some vehicles might activate their fog tail lights too.

First time surprised me my because I didn't know the car had the feature. Slammed the brakes harder than normal and hazards flashed at double time. Driving a 2010 Alfa Romeo 159.

I have seen several - if you press hard enough to Activate ABS on dry road, you most likely will see the hazard lights on