NW 146TH Ave over Turkey Creek
Polk County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- NW 146TH Ave over Turkey Creek in Polk County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1937 and reconstructed in 2001, making it 88 years old at the 2025 inventory.
- It carries about 71 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 195 of the 548 inventoried bridges in Polk County rated fair (35.6%); 34 (6.2%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated September 2023, on a 24-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- 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 → (41.82763, -93.77293)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 91 ft |
| Location | 0.2 Mi. E of Old Ia 415 |
| NBI structure number | 000000000283200 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | September 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Polk County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-235 over Drainage Ditch | 1966 | 118,600 | Fair |
| I-235 & 17TH St over Blue Creek | 1968 | 113,200 | Fair |
| I 235 over Des Moines Rvr Rbrtraydr | 1962 | 88,200 | Good |
| I-35 & I-80 over N Walnut Creek | 1958 | 81,600 | Fair |
| I 35 over Trib to Four Mile Creek | 2018 | 58,300 | Good |
| EB I-235 over Walnut Creek | 1968 | 58,050 | Fair |
All bridges nearby: Polk County, IA bridge conditions · every bridge in Polk County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.