As, I should imagine, with so many shots on this subject, it's a question of where you draw the line between chaos and complicated order - which is my first impression on seeing this. Any well composed photo is bound to suffer perhaps from seeming too irganised to represent chaos - perhaps explains the small number of entries. A fine photograph, although it really doesn't speak of chaos to me - nevertheless, a 7.
I'm not sure this really works for me in a chaotic way because it doesn't look all that crowded...with people or trains. Maybe there are just more trains than usual?