Ia 48 over Overflow Nishnabotna
Montgomery County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ia 48 over Overflow Nishnabotna in Montgomery County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1973, making it 52 years old at the 2025 inventory.
- It carries about 1,210 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 113 of the 209 inventoried bridges in Montgomery County rated fair (54.1%); 52 (24.9%) 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 March 2023, 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 → (41.14559, -95.17921)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 142 ft |
| Location | 2.0 mi. S of Jct. SR H14 |
| NBI structure number | 000000000037771 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Montgomery County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ia 48 over Stream | 1931 | 7,600 | Fair |
| US 34 over East Nishnabotna River | 1964 | 4,460 | Fair |
| Ia 48 over Red Oak Creek | 1918 | 4,460 | Fair |
| US 34 over Indian Creek | 1964 | 4,030 | Fair |
| US 34 over Crabapple Creek | 1964 | 4,030 | Fair |
| US 34 over West Tarkio Creek | 1964 | 3,990 | Fair |
All bridges nearby: Montgomery County, IA bridge conditions · every bridge in Montgomery County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.