NB I-380 over San Marnan DR
GoodBlack Hawk County, Iowa · 1.1 Mi. N of N Jct. US 20 · Structure no. 000000000605295
- Built
- 1983
- 42 years old
- Condition
- Good
- inspected August 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 181 ft
- 3 main spans
- Daily traffic
- 9,050
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
NB I-380 over San Marnan DR is a prestressed concrete stringer/multi-beam or girder carrying NB I-380 over San Marnan DR in Black Hawk County, Iowa. It was built in 1983, so it is 42 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 9,050 vehicles a day, roughly 14% of them trucks, projected to reach 9,050 by 2043. The structure is 181 ft (55.2 m) long and 55 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 | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was NB I-380 over San Marnan DR built?
It was built in 1983, making it 42 years old in 2025.
What condition is NB I-380 over San Marnan DR 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 August 2023.
How much traffic does NB I-380 over San Marnan DR carry?
About 9,050 vehicles per day (2022 count), of which roughly 14% are trucks.
How long is NB I-380 over San Marnan DR?
The structure is 181 ft (55.2 m) long with a longest span of 96 ft (29.3 m) and a deck 55 ft wide.
Who owns NB I-380 over San Marnan DR?
It is owned by the State Highway Agency.