M-68|m-33 over Black River
Cheboygan County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M-68|m-33 over Black River in Cheboygan 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 2002, making it 23 years old at the 2025 inventory.
- It carries about 3,521 vehicles a day (traffic count year 2007).
- Its listed owner is the state highway agency.
- It is one of 45 of the 73 inventoried bridges in Cheboygan County rated fair (61.6%); 10 (13.7%) 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 June 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 → (45.35513, -84.2917)
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 | Prestressed concrete multiple box beam |
| Length | about 84 ft |
| Location | E Lts of Tower |
| NBI structure number | 000000000001490 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Cheboygan County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Lincoln Avenue over Cheboygan River | 2007 | 12,000 | Fair |
| M-68|s Straits Hwy over Sturgeon River | 1927 | 10,873 | Fair |
| I-75 SB over Trowbridge Rd | 1962 | 7,875 | Fair |
| I-75 NB over Trowbridge Rd | 1962 | 7,875 | Fair |
| I-75 SB over M-27|s Straits Hwy | 1962 | 7,777 | Fair |
| I-75 NB over M-27|s Straits Hwy | 1962 | 7,777 | Fair |
All bridges nearby: Cheboygan County, MI bridge conditions · every bridge in Cheboygan County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.