I’m a bit late to reply, but this is a great explanation. I always assumed it was just the softness of asphalt vs concrete on the knees, but there is absolutely a case to be made for visibility. It’s unexpected as a cyclist, but I am 100% empathetic to the struggles of anyone not in a car, more specifically one of those Dodge Ram 3500s with smokestacks and truck nuts on the bumper that seem to be so popular right now. :-)