Gratiot over Canal
St. Clair County, Michigan · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Gratiot over Canal in St. Clair County, Michigan, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1955, making it 70 years old at the 2025 inventory.
- It carries about 9,072 vehicles a day (traffic count year 2012).
- Its listed owner is a city or municipal highway agency.
- It is one of 130 of the 326 inventoried bridges in St. Clair County rated good (39.9%); 31 (9.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (43.0239, -82.43438)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 53 ft |
| Location | In Port Huron |
| NBI structure number | 000000000010258 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 4: foundations stable, field review says exposed foundations need protection |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in St. Clair County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-94 over Stocks Creek Drain | 2011 | 50,660 | Good |
| I-94 & I-69 over M-25 Pine Grove Ave | 1993 | 43,238 | Good |
| M-25 over Black River Spillway | 2000 | 40,250 | Fair |
| I-94 over Stocks Creek | 1964 | 29,650 | Fair |
| M-25 over Howe Drain | 1981 | 28,550 | Fair |
| I-94 & I-69 WB over Black River & Scott Ave | 2011 | 26,010 | Fair |
All bridges nearby: St. Clair County, MI bridge conditions · every bridge in St. Clair County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.