I don't think loud pipes save lives all that much to be honest. A person in a car can't hear your pipes till you just about next to them, so if they don't actually see you, and go to change lanes, you better be skilled.
They can hear ya commin if there at a cross street, but they still have to spot ya. I think a headlight modulator does much more to keeping you safe then loud pipes.
Note, I have extremely loud pipes, and have people change into my lane with me right next to them all the time.
