US Bridges

Foss River Road over Foss River

Fair

King County, Washington · 0.8 MI SE SR-2 MP 50.6 · Structure no. 084349000000000

Built
1951
74 years old
Condition
Fair
inspected June 2024
Type
Truss - Thru
Steel
Length
122 ft
1 main span
Daily traffic
40
2024 count
Owner
County
County Highway Agency

About this bridge

Foss River Road over Foss River is a steel truss - thru carrying Foss River Road over Foss River in King County, Washington. It was built in 1951, so it is 74 years old, older 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 5 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 40 vehicles a day, roughly 5% of them trucks, projected to reach 60 by 2044. The structure is 122 ft (37.2 m) long and 17 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesFoss River Road
CrossesFoss River
Location0.8 MI SE SR-2 MP 50.6
RouteCounty Highway 89940
CountyKing County
StateWashington
Coordinates47.70451, -121.30542
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating25.7 US tons
Inventory rating19.6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1 (+1 approach)
Design loadHS 20
Structure length122 ft (37.2 m)
Longest span82 ft (25 m)
Deck width17 ft (5.3 m)
Roadway width14 ft (4.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2024)
Projected traffic60 by 2044
Trucks5%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$1.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Foss River Road over Foss River built?

It was built in 1951, making it 74 years old in 2025.

What condition is Foss River Road over Foss River 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 June 2024.

How much traffic does Foss River Road over Foss River carry?

About 40 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Foss River Road over Foss River?

The structure is 122 ft (37.2 m) long with a longest span of 82 ft (25 m) and a deck 17 ft wide.

Who owns Foss River Road over Foss River?

It is owned by the County Highway Agency.