SR 18 over M Street
GoodKing County, Washington · 0.6 E JCT SR 164 · Structure no. 0012555A0000000
- Built
- 1984
- 41 years old
- Condition
- Good
- inspected November 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 119 ft
- 1 main span
- Daily traffic
- 31,748
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SR 18 over M Street is a prestressed concrete stringer/multi-beam or girder carrying SR 18 over M Street in King County, Washington. It was built in 1984, so it is 41 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 31,748 vehicles a day, roughly 11% of them trucks, projected to reach 45,853 by 2039. The structure is 119 ft (36.3 m) long and 85 ft wide. If it were closed, the detour would be 6.2 mi (10 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 M Street built?
It was built in 1984, making it 41 years old in 2025.
What condition is SR 18 over M Street 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 November 2023.
How much traffic does SR 18 over M Street carry?
About 31,748 vehicles per day (2023 count), of which roughly 11% are trucks.
How long is SR 18 over M Street?
The structure is 119 ft (36.3 m) long with a longest span of 119 ft (36.3 m) and a deck 85 ft wide.
Who owns SR 18 over M Street?
It is owned by the State Highway Agency.