Ia 4 over Reading Creek
Calhoun County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ia 4 over Reading Creek in Calhoun 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 1952, making it 73 years old at the 2025 inventory.
- It carries about 300 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 99 of the 198 inventoried bridges in Calhoun County rated fair (50.0%); 49 (24.7%) 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 May 2024, 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 → (42.22206, -94.47514)
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 82 ft |
| Location | 3.1 mi. S of S jct IA 175 |
| NBI structure number | 000000000016900 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | May 2024 |
| 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 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.