Structure 4145 · Iosco County, MI
Carries National City RD over County Drain, 0.01 Mi N Of Dyer.
A culvert 22 ft across. 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 | Michigan |
| County | Iosco |
| Location | 0.01 Mi N Of Dyer |
| Carries | National City RD |
| Crosses | County Drain |
| Coordinates | 44.16209, -83.72221 |
| Material | Concrete |
| Design | Culvert |
| Total Length | 22.0 ft (6.7 m) |
| Max Span | 20.0 ft (6.1 m) |
| Deck Area | 50.9 sq m |
| Main Spans | 1 |
| Year Built | 2002 |
| Avg Daily Traffic | 390 (2006) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
| Last Inspection | June 2024 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | 000000000004145 |
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.