I think the building's actual size, and the length (circumference?) of those circles, is hard to tell from that image. It's probably a lot bigger than we're imagining. (Plus, maybe the ride vehicle moves very slow for a longer ride, and allows more cars on the track than we're imagining?)
Look towards the bottom-center of the image, where the crane is sitting, between the two circles. There's a cut-out section of outer circle wall on the right circle that looks to me where the load/unload areas may be. You can see the concrete walkways leading to those areas.
Wide shot I grabbed from
the video, showing the other ride being built on the right