Urban poetry

I'm not sure what this is -- some kind of cable stretching over one of the ramps leading to the Lincoln Tunnel. 

I'm sure it's not merely decorative, but it doesn't seem to be supporting anything and I don't have a clue as to the function of those metal circles. But with the Empire State Building (and pigeons perched on a lamppost) in the background, it makes a nice stanza of urban poetry.