SR 18 over Kent-Black Diamond RD
GoodKing County, Washington · 6.2 E JCT SR 164 · Structure no. 0014768A0000000
- Built
- 1996
- 29 years old
- Condition
- Good
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 271 ft
- 3 main spans
- Daily traffic
- 26,257
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SR 18 over Kent-Black Diamond RD is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 18 over Kent-Black Diamond RD in King County, Washington. It was built in 1996, so it is 29 years old, younger than the Washington average of 49.8 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 26,257 vehicles a day, roughly 14% of them trucks, projected to reach 37,992 by 2039. The structure is 271 ft (82.6 m) long and 40 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 SR 18 over Kent-Black Diamond RD built?
It was built in 1996, making it 29 years old in 2025.
What condition is SR 18 over Kent-Black Diamond RD 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 March 2024.
How much traffic does SR 18 over Kent-Black Diamond RD carry?
About 26,257 vehicles per day (2023 count), of which roughly 14% are trucks.
How long is SR 18 over Kent-Black Diamond RD?
The structure is 271 ft (82.6 m) long with a longest span of 93 ft (28.3 m) and a deck 40 ft wide.
Who owns SR 18 over Kent-Black Diamond RD?
It is owned by the State Highway Agency.