What is interesting is that Iowa rates this bridge as being "basically intolerable", while Illinois rates it as "minimum adequacy to tolerate being left in place." If that isn't faint praise, I don't know what is. As a result, this bridge is probably on the short list to be replaced. However, the low traffic count probably will not give the bridge replacement priority for funding.
This bridge has a rather interesting design. Notice that the cables are straight on the ends of the bridge, but sag in a curve between the towers. The reason for the cables being straight outside of the towers is that there are no vertical cables hanging down to support the bridge. If you look at a typical suspension bridge, there are vertical cables, and that pulls down on the main cables, causing them to form curves. This unique design is called an unloaded backspan. The result is that the main cables only support the main span, and do not support the spans outside of the towers.