Duncan over Stillwater River
Darke County, Ohio · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Duncan over Stillwater River in Darke County, Ohio, 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 1983, making it 42 years old at the 2025 inventory.
- It carries about 477 vehicles a day (traffic count year 2015).
- Its listed owner is the county highway agency.
- It is one of 75 of the 463 inventoried bridges in Darke County rated fair (16.2%); 2 (0.4%) 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 → (40.23825, -84.67167)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 8 | Very good condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 8 | Very good condition |
Bridge details
| Structure | Steel through truss |
| Length | about 86 ft |
| Location | .16 Mi N Duvall |
| NBI structure number | 1951033 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Ohio department of transportation.
Busiest bridges in Darke County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SR-121 over Greenville Creek | 1934 | 12,951 | Good |
| SR-49 over Greenville Creek | 1907 | 11,293 | Good |
| Usr-36 over SR 571 | 1969 | 9,298 | Good |
| SR-49 over Pansing Joint Ditch 433 | 1989 | 7,912 | Good |
| SR-49 over Dividing Branch | 1994 | 7,818 | Good |
| SR-49 over Bridge Creek | 1989 | 7,714 | Good |
All bridges nearby: Darke County, OH bridge conditions · every bridge in Darke County · Ohio bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.