420th ST over Drainage
GoodPottawattamie County, Iowa · 00000 · Structure no. 000000000287472
- Built
- 2011
- 14 years old
- Condition
- Good
- inspected May 2023
- Type
- Stringer/Multi-beam or Girder
- Concrete
- Length
- 30 ft
- 1 main span
- Daily traffic
- 29
- 2021 count
- Owner
- County
- County Highway Agency
About this bridge
420th ST over Drainage is a concrete stringer/multi-beam or girder carrying 420th ST over Drainage in Pottawattamie County, Iowa. It was built in 2011, so it is 14 years old, younger than the Iowa average of 45.5 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 29 vehicles a day, projected to reach 29 by 2043. The structure is 30 ft (9.1 m) long and 26 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 8 Very Good | No problems noted. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 8 Very Good | No problems noted. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 420th ST over Drainage built?
It was built in 2011, making it 14 years old in 2025.
What condition is 420th ST over Drainage in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2023.
How much traffic does 420th ST over Drainage carry?
About 29 vehicles per day (2021 count).
How long is 420th ST over Drainage?
The structure is 30 ft (9.1 m) long with a longest span of 30 ft (9.1 m) and a deck 26 ft wide.
Who owns 420th ST over Drainage?
It is owned by the County Highway Agency.