Your encounter reminded me of being passed by a guy on a Ducati Multistrada on US129 a few miles north of Deal's Gap. My progress up the mountain had been slowed by a couple on a cruiser who had just pulled into a turn-off and I was too focused on the road ahead to see him come up behind me. I did not pull to the right to allow him to pass on our side of the yellow. I managed to keep some sort of pace with him for the remainder of the ride to Deal's Gap Resort and we had a nice conversation about bikes and riding (which included an apology from me for not seeing him) before heading our separate ways. Encounters like these are fairly rare in four wheeled vehicles. Part of the reason that I love riding the two wheeled ones.