SH 55 over Payette River
FairBoise County, Idaho · 2.0 N. Horseshoe Bend · Structure no. 000000000014775
- Built
- 1971
- 54 years old
- Condition
- Fair
- inspected May 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 376 ft
- 4 main spans
- Daily traffic
- 7,800
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SH 55 over Payette River is a prestressed concrete stringer/multi-beam or girder carrying SH 55 over Payette River in Boise County, Idaho. It was built in 1971, so it is 54 years old, older than the Idaho average of 45.3 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 7,800 vehicles a day, roughly 5% of them trucks, projected to reach 11,700 by 2042. The structure is 376 ft (114.6 m) long and 40 ft wide. If it were closed, the detour would be 8.1 mi (13 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 SH 55 over Payette River built?
It was built in 1971, making it 54 years old in 2025.
What condition is SH 55 over Payette 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 May 2024.
How much traffic does SH 55 over Payette River carry?
About 7,800 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is SH 55 over Payette River?
The structure is 376 ft (114.6 m) long with a longest span of 92 ft (28 m) and a deck 40 ft wide.
Who owns SH 55 over Payette River?
It is owned by the State Highway Agency.