M-66 over West Branch R (coyle CR)
Osceola County, Michigan · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M-66 over West Branch R (coyle CR) in Osceola County, Michigan, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 7 (good condition) on the 0-9 scale.
- It was built in 1940 and reconstructed in 2015, making it 85 years old at the 2025 inventory.
- It carries about 1,864 vehicles a day (traffic count year 2014).
- Its listed owner is the state highway agency.
- It is one of 36 of the 103 inventoried bridges in Osceola County rated good (35.0%); 7 (6.8%) 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 August 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 → (44.03324, -85.14778)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 8 | 8 | Very good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete single box beam |
| Length | about 23 ft |
| Location | 0.1 Mi N of M-115 |
| NBI structure number | 000000000008592 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 7: scour countermeasures installed |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Osceola County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-131 NB over E Br Hersey River | 1957 | 12,782 | Fair |
| US-131 NB over Hersey Creek | 1985 | 11,841 | Fair |
| US-131 SB over Hersey Creek | 1985 | 11,841 | Fair |
| US-10 over Twin Creek | 1997 | 11,184 | Good |
| US-10 over Hersey River | 1958 | 6,569 | Fair |
| US-131 NB over Johnson Creek | 1984 | 6,391 | Fair |
All bridges nearby: Osceola County, MI bridge conditions · every bridge in Osceola County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.