L20 Loess Hills over Boyer River
FairHarrison County, Iowa · 078442210 · Structure no. 000000000027801
- Built
- 1991
- 34 years old
- Condition
- Fair
- inspected January 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 294 ft
- 3 main spans
- Daily traffic
- 1,065
- 2022 count
- Owner
- County
- County Highway Agency
About this bridge
L20 Loess Hills over Boyer River is a steel continuous stringer/multi-beam or girder carrying L20 Loess Hills over Boyer River in Harrison County, Iowa. It was built in 1991, so it is 34 years old, younger than the Iowa average of 45.5 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 1,065 vehicles a day, roughly 11% of them trucks, projected to reach 1,065 by 2044. The structure is 294 ft (89.6 m) long and 39 ft wide. If it were closed, the detour would be 3.7 mi (6 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was L20 Loess Hills over Boyer River built?
It was built in 1991, making it 34 years old in 2025.
What condition is L20 Loess Hills over Boyer River in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in January 2024.
How much traffic does L20 Loess Hills over Boyer River carry?
About 1,065 vehicles per day (2022 count), of which roughly 11% are trucks.
How long is L20 Loess Hills over Boyer River?
The structure is 294 ft (89.6 m) long with a longest span of 119 ft (36.3 m) and a deck 39 ft wide.
Who owns L20 Loess Hills over Boyer River?
It is owned by the County Highway Agency.