Structure 8311500000000 · Carroll County, IL
Carries N Blue Mountain RD over Brnch Of Plum River, 5.5 Mi N Mt. Carroll.
A culvert 24 ft across with 4 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 | Illinois |
| County | Carroll |
| Location | 5.5 Mi N Mt. Carroll |
| Carries | N Blue Mountain RD |
| Crosses | Brnch Of Plum River |
| Coordinates | 42.18469, -90.02308 |
| Material | Concrete |
| Design | Culvert |
| Total Length | 24.0 ft (7.3 m) |
| Max Span | 4.6 ft (1.4 m) |
| Deck Area | 31.4 sq m |
| Main Spans | 4 |
| Year Built | 2004 |
| Avg Daily Traffic | 10 (2021) |
| Lanes On Bridge | 2 |
| Last Inspection | May 2024 |
| Inspection Frequency | Every 24 months |
| Owner | Town/Township Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 008311500000000 |
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.