Structure 9987 · St. Clair County, MI
Carries I-94 EB over ST Clair River Cn Rr, At Port Huron.
6,111 ft end to end, longest span 922 ft: about 17 football fields, or 1.2 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 through arch.
| State | Michigan |
| County | St. Clair |
| Location | At Port Huron |
| Carries | I-94 EB |
| Crosses | ST Clair River Cn Rr |
| Coordinates | 42.99896, -82.42511 |
| Material | Steel Continuous |
| Design | Arch - Thru |
| Total Length | 6110.6 ft (1862.5 m) |
| Max Span | 921.9 ft (281 m) |
| Deck Width | 51.5 ft (15.7 m) |
| Deck Area | 29241.2 sq m |
| Main Spans | 3 |
| Year Built | 1997 |
| Avg Daily Traffic | 6,542 (2016) |
| Truck Traffic | 36% |
| Lanes On Bridge | 3 |
| Lanes Under Bridge | 16 |
| Last Inspection | October 2024 |
| Inspection Frequency | Every 12 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 9 — Foundation above flood level |
| Structure Number | 000000000009987 |
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.