Black River Road over Upper Black River
Cheboygan County, Michigan · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Black River Road over Upper Black River in Cheboygan County, Michigan, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1935, making it 90 years old at the 2025 inventory.
- It carries about 1,500 vehicles a day (traffic count year 2005).
- Its listed owner is the county highway agency.
- It is one of 10 of the 73 inventoried bridges in Cheboygan County rated poor (13.7%); 10 (13.7%) are rated poor.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (45.4679, -84.30305)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 4 | Poor condition |
| Superstructure | 4 | Poor condition |
| Substructure | 4 | Poor condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 120 ft |
| Location | Sec 34 T36N R1E |
| NBI structure number | 000000000001537 |
| Condition class | Poor |
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.