I agree that riding defensively can be a lifesaver. However, the problem is that we are invisible. I was waiting to make a left turn at a light this afternoon (in the middle of the lane, just behind the stop line, wearing bright yellow) and a car came around a corner and headed straight for me, with the driver looking straight through me, until I shouted. At the last moment she veered away. The only way I can put this together is that her brain must have been saying "Is there a car there? Nope. OK, I can go there."

140 dB would have been very useful.