WB US 30 over Grant Creek
Story County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- WB US 30 over Grant Creek in Story County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1991, making it 34 years old at the 2025 inventory.
- It carries about 8,450 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 102 of the 302 inventoried bridges in Story County rated good (33.8%); 40 (13.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (good), but component ratings moved: substructure 8 to 7.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (42.009, -93.51649)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 8 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 83 ft |
| Location | 2.8 Mi. E of Jct. I-35 |
| NBI structure number | 000000000048785 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 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 Story County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-35 over Ballard Creek | 1964 | 48,300 | Fair |
| I-35 over Walnut Creek | 1964 | 48,300 | Fair |
| I 35 over South Skunk Rvr Overflow | 2017 | 48,300 | Good |
| I-35 over Drainage Ditch | 1967 | 28,300 | Good |
| US 69 over Ioway Creek | 1924 | 24,600 | Good |
| NB I-35 over Bike Path | 1964 | 24,150 | Fair |
All bridges nearby: Story County, IA bridge conditions · every bridge in Story County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.