US Bridges

1st Ave S over Argo RR Yard

Fair

King County, Washington · 4500 1st Ave S · Structure no. 085274000000000

Built
1935
90 years old, rebuilt 1989
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
2,544 ft
14 main spans
Daily traffic
19,000
2019 count
Owner
City
City or Municipal Highway Agency

About this bridge

1st Ave S over Argo RR Yard is a steel continuous stringer/multi-beam or girder carrying 1st Ave S over Argo RR Yard in King County, Washington. It was built in 1935 and reconstructed in 1989, so it is 90 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 19,000 vehicles a day, roughly 10% of them trucks, projected to reach 25,000 by 2045. The structure is 2,544 ft (775.4 m) long and 68 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries1st Ave S
CrossesArgo RR Yard
Location4500 1st Ave S
RouteCity Street 1140
CountyKing County
StateWashington
Coordinates47.56361, -122.33417
Functional classUrban Other Principal Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans14 (+17 approach)
Design loadHS 20
Structure length2,544 ft (775.4 m)
Longest span101 ft (30.8 m)
Deck width68 ft (20.7 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic19,000 (2019)
Projected traffic25,000 by 2045
Trucks10%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway and railroad
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$62.8 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was 1st Ave S over Argo RR Yard built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 1989.

What condition is 1st Ave S over Argo RR Yard 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 July 2023.

How much traffic does 1st Ave S over Argo RR Yard carry?

About 19,000 vehicles per day (2019 count), of which roughly 10% are trucks.

How long is 1st Ave S over Argo RR Yard?

The structure is 2,544 ft (775.4 m) long with a longest span of 101 ft (30.8 m) and a deck 68 ft wide.

Who owns 1st Ave S over Argo RR Yard?

It is owned by the City or Municipal Highway Agency.