Structure 4057 · Kodiak Island County, AK
Carries Chiniak Highway over West Fork Twin Creek, Mile Point 28.5.
A culvert 24 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 | Alaska |
| County | Kodiak Island |
| Location | Mile Point 28.5 |
| Carries | Chiniak Highway |
| Crosses | West Fork Twin Creek |
| Coordinates | 57.62100, -152.26516 |
| Material | Steel |
| Design | Culvert |
| Total Length | 24.0 ft (7.3 m) |
| Max Span | 11.2 ft (3.4 m) |
| Deck Area | 62.0 sq m |
| Main Spans | 1 |
| Year Built | 1975 |
| Avg Daily Traffic | 166 (2018) |
| Truck Traffic | 11% |
| Lanes On Bridge | 2 |
| Last Inspection | September 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 | 4057 |
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.