No special line, but, they do ask and it is a really strange situation for anyone to ride alone. They fill every seat even if you have never seen your fellow rider before in your life. I never noticed if they did give out a notice that they were doing that on the ride, but, if they don't have one, they should. I was, not upset, but, surprised when I was placed in a spot thinking that I was riding by myself only to have someone jump into the seat next to me. It wasn't a problem, just a surprise. However, they do not ask until you get ready to load. There is no shorter line for people riding single.