That's a big pet peeve of mine. I had another "courteous" (or stupid) cager today, I needed to get left before a freeway on ramp, and some woman in an SUV w/Florida plates slows down, hangs about three inches from my rear wheel and just stares at me, wouldn't given me enough space to safely get in front of her, wouldn't speed up. Finally gave her a shoulder shrug and yelled "what the hell do you want me to do, lady?" and she sped off. I've dealt with small animals that have better reasoning powers than some cagers.