CR 489(RED Oak Rd) over Au Sable River
Oscoda County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- CR 489(RED Oak Rd) over Au Sable River in Oscoda County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1959, making it 66 years old at the 2025 inventory.
- It carries about 1,540 vehicles a day (traffic count year 2005).
- Its listed owner is the county highway agency.
- It is one of 7 of the 15 inventoried bridges in Oscoda County rated fair (46.7%); 3 (20.0%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: deck 6 to 5.
- Its most recent inspection on record is dated October 2024, 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 → (44.67674, -84.29214)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 129 ft |
| Location | Sec 2-3 Big Creek Twp |
| NBI structure number | 000000000008667 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Oscoda County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| M-33|m-72|n Mount over Au Sable River | 1984 | 8,950 | Fair |
| M-72|cripps Rd over E Br Big Creek | 1960 | 2,656 | Fair |
| Deeter Road over West Br Big Creek | 2001 | 2,100 | Good |
| M-72|park Rd over W Br Big Creek | 1957 | 2,064 | Fair |
| Mckinley Rd(c 600) over Perry Creek | 2003 | 1,440 | Good |
| Mckinley Rd(c 600) over Commins Creek | 2003 | 1,440 | Fair |
All bridges nearby: Oscoda County, MI bridge conditions · every bridge in Oscoda County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.