Gordon, I think they are from the guest place on towers street. I'm guessing they open with the park.
I'm going tomorrow and after a couple I think, although we are happy to single ride so we may do that instead and save our money.
Does anyone know if the single rider queue is seperate from the main queue and opens when the ride opens?
The single rider queue is a separate queue from the main queue, and it is the same queue those with a disabled pass or fastpass use, before it splits into 3 different queues.
I'm not sure if it opens right from when the ride opens, but you're unable to queue for it like you do for the main queue, during ERT (as far as I'm aware). However, there have been reports that the SRQ gets closed if it becomes too long.