Structure 4317 · Mobile County, AL
Carries US 90 over Bolton Ditch, 0.6 Mi E I-65.
A culvert 21 ft across with 3 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 | Alabama |
| County | Mobile |
| Location | 0.6 Mi E I-65 |
| Carries | US 90 |
| Crosses | Bolton Ditch |
| Coordinates | 30.65714, -88.11399 |
| Material | Concrete |
| Design | Culvert |
| Total Length | 21.0 ft (6.4 m) |
| Max Span | 7.9 ft (2.4 m) |
| Deck Area | 119.0 sq m |
| Main Spans | 3 |
| Year Built | 1952 |
| Avg Daily Traffic | 19,411 (2023) |
| Truck Traffic | 2% |
| Lanes On Bridge | 5 |
| Last Inspection | July 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 004317 |
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.