The symmetry of the bridge, the way the towers (I know that's not what they're called, but the actual word escapes me...) comes together as a triangle pointing upward with the suspensions cables extending toward the viewer, along with the ominous clouds, makes for a wonderfully foreboding, cold, mechanical photo. It has a life-after-humans feel to it. This is brilliant--I love it.
Amazing perspective, and fantastic detail! The black and white option on a camera is fantastic to use for monuments and other still objects such as these. It seems to bring out the subject in the picture, and you did the job fantastically!
Here's something similar that I did. ^^ I too enjoy the black and white.