FM over Dd
Calhoun County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- FM over Dd in Calhoun County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1973, making it 52 years old at the 2025 inventory.
- It carries about 30 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 49 of the 198 inventoried bridges in Calhoun County rated poor (24.7%); 49 (24.7%) are rated poor.
- Its traffic status in the 2025 inventory is open, posting recommended but not legally implemented (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Status change: its 2024 load posting has been removed.
- Its most recent inspection on record is dated July 2024, on a 12-month routine inspection cycle.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.42787, -94.62361)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 3 | 3 | Serious condition |
Bridge details
| Structure | Concrete channel beam |
| Length | about 30 ft |
| Location | 088321901 |
| NBI structure number | 000000000091951 |
| Condition class | Poor |
| Traffic status (item 41) | Open, posting recommended but not legally implemented |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 12 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 Iowa department of transportation.
Busiest bridges in Calhoun County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 over East Cedar Creek | 2008 | 7,000 | Good |
| US 20 over Dd 9 & 13 | 2008 | 6,900 | Good |
| US 20 over W Fork Camp Creek | 2010 | 5,900 | Good |
| US 20 over Drainage Ditch No 1 & 54 | 2010 | 5,900 | Good |
| US 20 WB over Cc RR | 2011 | 3,450 | Good |
| US 20 EB over Cc RR | 2010 | 3,450 | Good |
All bridges nearby: Calhoun County, IA bridge conditions · every bridge in Calhoun County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.