CM: please go this way.
Me: I need to avoid stairs *points to alternate loading area*
CM: Single riders go this way *points to regular line*
I'm not sure about the regular line, but the way the single rider line generally gets up to the actual ride vehicles is a two part ramp with a turn.
There are stairs up as well (on the side if you go left toward the wheelchair loading area) but I've never been sent up them as a single. It's actually usually chained off. I've always been directed up the ramp, which makes sense as it holds more people. So if you were in the single rider line, you probably wouldn't have ended up on stairs anyway.