The engine revving may have caused situational deafness, so to speak, in the, uh, allegedly unpleasant female driver. Said differently, and by way of example: Living in Cruiser Central as I do, the pointless engine blipping/revving from the Loud Pipes brigade is ceaseless during the summer months. Consequently, I've conditioned myself to tune it out. The biker who uses engine revving as a proxy for a horn (where it's use would in fact be appropriate), particularly in heavy or stopped traffic, would likely get no response from me. That's the reality that they've created for themselves, and for that I make no apology. Perhaps the C U Next Tuesday was capriciously blocking the leading rider's line of travel. Sans the rider's ability to use his horn button, her behavior may remain a mystery.