Hi Ed, Interesting use of "real" IR, it creates a very powerful and ominous feel, yet I'm not sure if the roller coaster is the best suitable subject to photograph in IR. Correct me if I'm wrong, I'm lead to believe the biggest effect with IR is achieved when the subject itself has all colours of the spectrum, changing blue to black, green to white, thus making full use of the tonal range...
As to the composition, the structures supporting the tracks as well as the intricate line play creates a very powerful subject, that's for sure. I wonder if you had stepped in a bit closer, as well as chosen a different camera angle, if you could've created a more dynamic photo; maybe not capturing the overview, but just the combination of curves and rigid structures. A more abstract shot, perhaps, but I think it might well increase the impact of this photo. Hope you see what I mean.
0 
