I think the common thread for "wavers" is a sense of shared community and or happiness. I've always done it as a motorcyclist, a classic car owner and now with the RV (although admittedly not as often). When your on or in your "toy" and not your commuter car/truck going to/from work, you're in a better state of mind and acknowledging such with your fellow men & women who are also in their happy place (hopefully!)