Structure 9168 · Saginaw County, MI
Carries I-75 NB over Saginaw R M13 Gtwrr, At Zilwaukee.
Set by its lowest-rated component: Deck and Superstructure at 6 of 9.
How ratings work8,061 ft end to end, longest span 392 ft: about 22 football fields, or 1.5 miles. 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 or the layout of the shorter spans, so those are drawn as typical for a segmental box-girder bridge.
| State | Michigan |
| County | Saginaw |
| Location | At Zilwaukee |
| Carries | I-75 NB |
| Crosses | Saginaw R M13 Gtwrr |
| Coordinates | 43.47879, -83.90641 |
| Material | Prestressed Concrete Continuous |
| Design | Segmental Box Girder |
| Total Length | 8061.0 ft (2,457 m) |
| Max Span | 392.1 ft (119.5 m) |
| Deck Width | 74.5 ft (22.7 m) |
| Deck Area | 55773.9 sq m |
| Main Spans | 25 |
| Year Built | 1980 |
| Avg Daily Traffic | 23,450 (2007) |
| Truck Traffic | 7% |
| Lanes On Bridge | 4 |
| Lanes Under Bridge | 3 |
| Last Inspection | August 2023 |
| 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 | 000000000009168 |
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.