The reason to fit a car with an airbag is that it saves lives – that is, the lives of who ever happens to be sitting in the car. If the vehicle hits a pedestrian, his or her chances of survival are markedly less. That, too, could soon become history as several automotive manufacturers have started installing external airbags that respond to sensors and register if the vehicle will collide with a pedestrian. If that is the case, the front lid will open and a bag will inflate. If pedestrians, too, could be fitted with vests that inflate once cars come too close, the safety record would probably rise even more…