Structure 20860 · Clinton County, IA
Carries US 30 over Mississippi Rvr Rr S 2nd, In Clinton.
Set by its lowest-rated component: Superstructure and Substructure at 5 of 9.
How ratings work4,165 ft end to end: about 12 football fields. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a suspension bridge.
| State | Iowa |
| County | Clinton |
| Location | In Clinton |
| Carries | US 30 |
| Crosses | Mississippi Rvr Rr S 2nd |
| Coordinates | 41.83781, -90.19048 |
| Material | Steel |
| Design | Suspension |
| Total Length | 4165.0 ft (1269.5 m) |
| Max Span | 644.0 ft (196.3 m) |
| Deck Width | 32.8 ft (10 m) |
| Deck Area | 12,695 sq m |
| Main Spans | 1 |
| Year Built | 1956 (reconstructed 1999) |
| Avg Daily Traffic | 11,100 (2022) |
| Truck Traffic | 11% |
| Lanes On Bridge | 2 |
| Last Inspection | November 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | 000000000020860 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.