SH 55 over High Line Canal
FairCanyon County, Idaho · 4.5 N. Marsing · Structure no. 000000000014685
- Built
- 1974
- 51 years old
- Condition
- Fair
- inspected January 2024
- Type
- Frame
- Concrete
- Length
- 34 ft
- 1 main span
- Daily traffic
- 7,700
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SH 55 over High Line Canal is a concrete frame carrying SH 55 over High Line Canal in Canyon County, Idaho. It was built in 1974, so it is 51 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 7,700 vehicles a day, roughly 10% of them trucks, projected to reach 11,550 by 2042. The structure is 34 ft (10.4 m) long and 52 ft wide. If it were closed, the detour would be 3.1 mi (5 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 High Line Canal built?
It was built in 1974, making it 51 years old in 2025.
What condition is SH 55 over High Line Canal 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 SH 55 over High Line Canal carry?
About 7,700 vehicles per day (2023 count), of which roughly 10% are trucks.
How long is SH 55 over High Line Canal?
The structure is 34 ft (10.4 m) long with a longest span of 32 ft (9.8 m) and a deck 52 ft wide.
Who owns SH 55 over High Line Canal?
It is owned by the State Highway Agency.