That is exactly my argument against loud pipes as a "safety" feature. By the time someone can actually hear the sound well enough to look and determine where the sound is coming, how fast it is coming, whether its a threat or just sound, the rider is already WAY too close and the action choices are limited. Even on the streets at 35mph you cover 51 feet per second. Like you say, less than a second away the cage driver realizes you are there, and by then the rider's choices may be very limited; too close to act without using emergency responses. IF the rider has really good reaction skills there may be an out. But in my years of training "experienced" riders most often the louder the pipes the lower the skills.