I like the perspective of diminishing space from the tunnel effect. It seems off somehow, like off center or something - not sure exactly, but there's just that little something about it. I hope someone else commented that with more useful information.
Really nice photograph. I like looking at the steel and wood bridges. Can I be a bit honest with you? What if you waited almost until dark when perhaps there was more dramatic lighting in the sky? Shot it a little to the left or right instead of dead centre?