315TH St over Keg Creek
Harrison County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 315TH St over Keg Creek in Harrison 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 1999, making it 26 years old at the 2025 inventory.
- It carries about 20 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 61 of the 222 inventoried bridges in Harrison County rated good (27.5%); 41 (18.5%) are rated poor.
- 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 → (41.54961, -95.52902)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 127 ft |
| Location | 078412301 |
| NBI structure number | 000000000177061 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Harrison County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 30 over Willow Creek | 1972 | 10,300 | Fair |
| US 30 over UPRR | 1998 | 10,300 | Good |
| NB I-29 over Boyer River | 1958 | 10,050 | Fair |
| SB I-29 over Boyer River | 1958 | 10,050 | Fair |
| SB I-29 over over UP RR | 1967 | 7,750 | Fair |
| NB I-29 over Allen Creek | 1967 | 7,750 | Fair |
All bridges nearby: Harrison County, IA bridge conditions · every bridge in Harrison County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.