Looking even more awesome by the minute. I'm too surprised at how silent this thing is, although I suppose with such close proximity to the animals, this is a good thing.
Not doubt the ride is filled with sand. You can also get wheels that are designed to run quieter along the track.
Also add to the fact that it is a very long track and close to guests and other attractions in a lot of places.
No one wants a loud coaster constantly screaming by them when they are walking through the park.