Structure 221841 · Linn County, IA
Carries Chain Bridge Road over Lone Tree Creek, 000000000.
A culvert 25 ft across with 2 openings. 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, so those are drawn as typical for a culvert.
| State | Iowa |
| County | Linn |
| Location | 000000000 |
| Carries | Chain Bridge Road |
| Crosses | Lone Tree Creek |
| Coordinates | 42.05125, -91.78765 |
| Material | Concrete Continuous |
| Design | Culvert |
| Total Length | 24.6 ft (7.5 m) |
| Max Span | 12.1 ft (3.7 m) |
| Deck Area | 68.2 sq m |
| Main Spans | 2 |
| Year Built | 1984 |
| Avg Daily Traffic | 171 (2021) |
| Lanes On Bridge | 2 |
| Last Inspection | March 2023 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 000000000221841 |
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.