A third breaking light for trucks works!!
Problem: Breaking of trucks isn't very visible.
Solution: See the picture. Just like with cars a third breaking light for trucks is very visible. It would be good if all trucks would be equipped with one.
As a bonus; due to the high mounting point of the breaking light; it might be good to connect this to the emergency lights. When a truck would come to a complete stop, this would be far more visible for all other road users; even in worse weather conditions.
Another option would be to integrate flashing lights into the third breaking light for emergency purposes. Modern LED technic makes this possible.