I had a similar experience on the road heading west out of Clayton, NM one winter. There was snow on the road, and it was slick. There were 3 tire tracks on the road, for both directions (3 total) - the deal was, you drive with your left wheels on the yellow line, and only when there's a car coming do you both move to the right and risk running off the road. There was a guy tailgating me, same thing, speed up (as fast as I dared), slow down, no change. Finally, when we had to move over for some oncoming traffic, I started skating, which scared the crap out of me, so I slowed down, and down, and down, and finally came to a dead stop. Tailgater waited back there a few seconds, then pulled alongside and stopped (in the oncoming lane, mind you), rolled down his right side window, and asked if I needed help. I replied, "No, I need you to stop tailgating me." He gave me a funny look and went on. And he was an old guy, too.