Grassmere Road over Pinnebog River
Huron County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Grassmere Road over Pinnebog River in Huron 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 1996, making it 29 years old at the 2025 inventory.
- It carries about 675 vehicles a day (traffic count year 2009).
- Its listed owner is the county highway agency.
- It is one of 116 of the 192 inventoried bridges in Huron County rated fair (60.4%); 14 (7.3%) are rated poor.
- 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 → (43.95074, -83.1265)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 156 ft |
| Location | Sec. 25 Lake Twp. |
| NBI structure number | 000000000003608 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Huron County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Anton Street over Sebewaing River | 2013 | 5,590 | Good |
| M-142 over Pinnebog River | 1946 | 5,274 | Good |
| M-142|pigeon Rd over Nettle Run | 2012 | 5,200 | Good |
| M-25 over Sebewaing River | 1949 | 5,123 | Fair |
| Center Street over Sebewaing River | 2003 | 4,900 | Fair |
| M-25 over Pigeon River | 1929 | 4,865 | Good |
All bridges nearby: Huron County, MI bridge conditions · every bridge in Huron County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.