Nothing new here. Volvo have a similar system that makes the brake lights flash under hard braking:
http://en.wikiped...ke_Light
Once the speed drops below 30kph the hazard warning lights flash. This is fitted as standard equipment in Europe, but not in the US for homologation reasons.

What ever is developed it MUST be standardized. If different brands or owners of trucks adopt different standards, drivers will be inundated with a bunch of flashing, blinking stop and hazard lamps and have no idea of what is going on.

I have my own method for telling if the car ahead of me is braking hard or not. If the car gets bigger fast...