I-90 over Highline Canal
PoorKittitas County, Washington · 4.8 E JCT SR 970 · Structure no. 0007574B0000000
- Built
- 1965
- 60 years old, rebuilt 1999
- Condition
- Poor
- inspected February 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 179 ft
- 2 main spans
- Daily traffic
- 14,717
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-90 over Highline Canal is a prestressed concrete stringer/multi-beam or girder carrying I-90 over Highline Canal in Kittitas County, Washington. It was built in 1965 and reconstructed in 1999, so it is 60 years old, older than the Washington average of 49.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 14,717 vehicles a day, roughly 23% of them trucks, projected to reach 18,248 by 2039. The structure is 179 ft (54.6 m) long and 52 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I-90 over Highline Canal built?
It was built in 1965, making it 60 years old in 2025. It was reconstructed in 1999.
What condition is I-90 over Highline Canal in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in February 2024.
How much traffic does I-90 over Highline Canal carry?
About 14,717 vehicles per day (2023 count), of which roughly 23% are trucks.
How long is I-90 over Highline Canal?
The structure is 179 ft (54.6 m) long with a longest span of 104 ft (31.7 m) and a deck 52 ft wide.
Who owns I-90 over Highline Canal?
It is owned by the State Highway Agency.