US Bridges

NW Seward Road over Salmon Creek

Fair

Clark County, Washington · JCT NW36 Ave&seward · Structure no. 082722000000000

Built
1985
40 years old
Condition
Fair
inspected November 2022
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete
Length
144 ft
1 main span
Daily traffic
11,465
2022 count
Owner
County
County Highway Agency

About this bridge

NW Seward Road over Salmon Creek is a prestressed concrete box beam or girders - single or spread carrying NW Seward Road over Salmon Creek in Clark County, Washington. It was built in 1985, so it is 40 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 11,465 vehicles a day, roughly 11% of them trucks, projected to reach 26,368 by 2038. The structure is 144 ft (43.9 m) long and 60 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesNW Seward Road
CrossesSalmon Creek
LocationJCT NW36 Ave&seward
RouteCounty Highway 91050
CountyClark County
StateWashington
Coordinates45.72302, -122.70722
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.4 US tons
Inventory rating28.5 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length144 ft (43.9 m)
Longest span144 ft (43.9 m)
Deck width60 ft (18.2 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,465 (2022)
Projected traffic26,368 by 2038
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$5.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was NW Seward Road over Salmon Creek built?

It was built in 1985, making it 40 years old in 2025.

What condition is NW Seward Road over Salmon 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 November 2022.

How much traffic does NW Seward Road over Salmon Creek carry?

About 11,465 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is NW Seward Road over Salmon Creek?

The structure is 144 ft (43.9 m) long with a longest span of 144 ft (43.9 m) and a deck 60 ft wide.

Who owns NW Seward Road over Salmon Creek?

It is owned by the County Highway Agency.