US Bridges

SR 18 over Carey Creek

Fair

King County, Washington · 4.0 E JCT SR 169 · Structure no. 0014567C0000000

Built
1995
30 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
210 ft
2 main spans
Daily traffic
15,522
2023 count
Owner
State
State Highway Agency

About this bridge

SR 18 over Carey Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 18 over Carey Creek in King County, Washington. It was built in 1995, so it is 30 years old, younger than the Washington average of 49.8 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 15,522 vehicles a day, roughly 17% of them trucks, projected to reach 23,413 by 2039. The structure is 210 ft (64 m) long and 40 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesSR 18
CrossesCarey Creek
Location4.0 E JCT SR 169
RouteState Highway 18
CountyKing County
StateWashington
Coordinates47.43122, -121.98578
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating43 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length210 ft (64 m)
Longest span103 ft (31.4 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,522 (2023)
Projected traffic23,413 by 2039
Trucks17%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 18 over Carey Creek built?

It was built in 1995, making it 30 years old in 2025.

What condition is SR 18 over Carey Creek 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 March 2024.

How much traffic does SR 18 over Carey Creek carry?

About 15,522 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is SR 18 over Carey Creek?

The structure is 210 ft (64 m) long with a longest span of 103 ft (31.4 m) and a deck 40 ft wide.

Who owns SR 18 over Carey Creek?

It is owned by the State Highway Agency.