Just finished a California to Maryland solo ride, US 50 mainly. Over six days, I waved to every rider I saw and received a return wave at least 95% of the time. I often found myself checking my mirror to see if I’d actually missed a bike that I saw in my peripheral vision (I hadn’t). I didn’t see any riders in a couple of states… Kansas (surprisingly, though it was Tuesday) and Kentucky (I was on the interstate early am between Louisville and Lexington), I think. In Nevada, several Harley “bikers” ahead of me gave a road hazard foot signal at one point (including the last rider).