I 90 over City County Drain Ditch
Yellowstone County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I 90 over City County Drain Ditch in Yellowstone County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1966, making it 59 years old at the 2025 inventory.
- It carries about 27,985 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 186 of the 290 inventoried bridges in Yellowstone County rated fair (64.1%); 7 (2.4%) 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 → (45.7522, -108.50988)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 5 | Fair condition |
Bridge details
| Structure | Steel culvert |
| Length | about 22 ft |
| Location | Billings |
| NBI structure number | I00090448+04001 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Yellowstone County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I90 over MT Power RR Spur | 2023 | 29,488 | Good |
| King Ave W over Bbwa Canal | 1994 | 26,602 | Fair |
| Mullowney Ln over RR | 2007 | 23,980 | Good |
| Mullowney Ln over RR | 2007 | 23,980 | Fair |
| US 87 over Int Lockwood I 90 | 1966 | 23,199 | Fair |
| US 87 over RR | 1993 | 23,199 | Fair |
All bridges nearby: Yellowstone County, MT bridge conditions · every bridge in Yellowstone County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.