Brake lights sensitive to braking force
blog.pedro.si
blog.pedro.si
Maybe it can be at least partially be achieved with LED lights that last many years and don't break easily, if at all. Anyways I have the impression that the quality of light bulbs has increased a lot since the burst of the auto industry.
I wrote about it back then (in Dutch, http://micheljansen.org/blog/entry/471) and at that time, there were some laws preventing this from really catching on. I guess those have been changed in the mean time?
Along a similar vein, I want car horns to be as loud inside a car as they are outside, to ensure they're only used for emergencies. I live in a city and car horns dramatically reduce quality of life because "no honking, $350 penalty" are never actually enforced by the police.
Here's the discussion: http://news.ycombinator.com/item?id=1779339
But increasing brake light intensity overall on new cars or replacement brake lamps would increase safety even though old cars might have weaker brake lights. Essentially an "Omigod!" mode.
It's quicker to recognise than a graded red brake light.
Maximum deceleration values of a car are about up to 1G for normal cars (found the data on an unofficial forum, so it may not be right)
Suppose a car in front of you brakes slowly, but for some reason you press harder the pedal, say to a deceleration of -5ms^-2 (1/2 G). Suppose a town with speed limit of 50km/h, and you and all cars drive at max speed. Suppose an initial car separation of 20m. If you do the calculations, you'll see that it will take less than 3 seconds for the back car to crash your car end. 3 secs sounds like a lot in reaction time, but the driver may be distracted, which may make him notice your braking a bit later, but not too late to apply appropriate braking and causing a car on his end.