Mo 221 S over Br Knob CR
Iron County, Missouri · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Mo 221 S over Br Knob CR in Iron County, Missouri, 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 1954 and reconstructed in 1991, making it 71 years old at the 2025 inventory.
- It carries about 2,220 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 76 of the 126 inventoried bridges in Iron County rated fair (60.3%); 13 (10.3%) 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 → (37.62119, -90.63664)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 5 | Fair condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 26 ft |
| Location | S 30 T 34 N R 4 E |
| NBI structure number | 7691 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Missouri department of transportation.
Busiest bridges in Iron County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Mo 21 S over Knob CR | 1967 | 6,248 | Fair |
| Old Rte 21 over Stouts CR | 1926 | 4,000 | Fair |
| Mo 21 S over Stouts CR | 1967 | 3,870 | Fair |
| Rt N N over UP RR | 2007 | 3,718 | Good |
| Rt N N over Indian CR | 1932 | 3,718 | Fair |
| Mo 21 S over Claybaugh CR | 1985 | 3,513 | Good |
All bridges nearby: Iron County, MO bridge conditions · every bridge in Iron County · Missouri bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.