I also wish to make it absolutely clear that "Structurally Deficient" does NOT mean that a bridge is unsafe for use. In the United States all bridges that are structurally unsafe are immediately closed to traffic. All structurally deficient bridges are safe for use if they are open to traffic and users follow all posted signage for weight and overhead clearance is obeyed. Structurally Deficient is just a fancy way of saying "needs some repair" in the same way your house might need some repairs, but yet at the same time is not unsafe to continue living in until you get around to making those repairs.
The term, structurally deficient, can sound scary. In truth, many bridges that are structurally deficient can be repaired. A lot of times, the reason a bridge gets listed as structurally deficient is due to deterioration on the bottom chord or the deck stringers. In these instances, the rest of the bridge may be in great shape. I am not a bridge inspector so I don't know the situation with this one.
Structurally deficient means your trucks can't keep getting bigger and heavier because of design loading. Functionally obsolete means more of the same, not designed for modern traffic. Fracture critical doesn't mean it's going to fall down tomorrow, either. Engineering terms.
Because I, and a lot of heavy trucks and commuter traffic cross this bridge a lot and it's listed here as Appraisal: Structurally deficient, might it be replaced before it falls in the river, and if so when please? I don't see it listed on the county master plan.
I've even seen that minor roadway cracking that happens to be on a bridge deck surface can render it as "structurally deficient". It does not say "structurally unsafe". As Nathan and Robert pointed out, it simply means that the bridge needs some sort of repair. When the sufficiency percentage falls below a certain point, the status becomes "structurally deficient". I don't know what that number is. In contrast, "functionally obsolete" does NOT mean structurally deficient--this simply means that the design of the bridge does not meet current FHA/DOT standards. Such factors as low overhead clearance, narrow lane widths, or lack of shoulders can be determining factors of functional obsolescence. A bridge can be in perfect structural condition and still be considered functionally obsolete.