I have yet to figure out how we can scientifically determine if loud pipes save lives. What do we do, equip 1000 folks with quiet bikes and 1000 folks with loud bikes, turn them loose in rush hour traffic, and then count how many make it to the other side of town in one piece?
My opinion is that defensive riding, high visibility, and good safety equipment saves lives. Excessively loud pipes mostly just piss people off and make new enemies for bikers. It's possible to ride with reasonably loud pipes and not alienate every non-deaf person and animal in a two mile radius, but all too often folks rev their bikes just to get attention or prove how macho they are (shame that juvenile behavior isn't limited to juveniles). As for loud pipes keeping folks in cages from moving over into your lane or pulling out in front of you, unless they are driving with their windows open and the stereo off, I don't buy that one at all. And if you've got time to rev your engine to warn a cager, I bet you also have enough time to hit the horn button. Folks need to quit using that loud pipes saves lives BS excuse and just admit they like making noise and being the center of attention. We've all been there at one time or another, but it's time to let the brain rule, not the hormones, before we get legislated out of existence or fined into poverty.
Jerry