Mackinac Trail over I-75 NB
Chippewa County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Mackinac Trail over I-75 NB in Chippewa County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1963, making it 62 years old at the 2025 inventory.
- It carries about 1,000 vehicles a day (traffic count year 2007).
- Its listed owner is the state highway agency.
- It is one of 73 of the 112 inventoried bridges in Chippewa County rated fair (65.2%); 13 (11.6%) 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 April 2023, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (46.33619, -84.42799)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 351 ft |
| Location | 2.9 Mi S of M-28 |
| NBI structure number | 000000000001579 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Chippewa County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-75 BS|3 Mile Rd over I-75 NB | 1962 | 15,700 | Fair |
| I-75 Bs (ashmun) over Power Canal | 1934 | 10,180 | Fair |
| Easterday Ave. over Ashmun Creek | 1994 | 8,347 | Good |
| Easterday Ave over I-75 NB | 1962 | 7,774 | Fair |
| West Portage Ave. over Power Canal | 1970 | 7,637 | Fair |
| Spruce St. over Power Canal | 1983 | 5,995 | Fair |
All bridges nearby: Chippewa County, MI bridge conditions · every bridge in Chippewa County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.