US Bridges

4th Ave S over Railroad Station

Fair

King County, Washington · 4th Ave S & Jackson ST · Structure no. 085050000000000

Built
1910
115 years old, rebuilt 1981
Condition
Fair
inspected July 2023
Type
Slab
Concrete Continuous
Length
1,178 ft
67 main spans
Daily traffic
13,500
2019 count
Owner
City
City or Municipal Highway Agency

About this bridge

4th Ave S over Railroad Station is a concrete continuous slab carrying 4th Ave S over Railroad Station in King County, Washington. It was built in 1910 and reconstructed in 1981, so it is 115 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 13,500 vehicles a day, roughly 5% of them trucks, projected to reach 16,470 by 2039. The structure is 1,178 ft (359.1 m) long and 45 ft wide.

Location

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Carries4th Ave S
CrossesRailroad Station
Location4th Ave S & Jackson ST
RouteCity Street 1140
CountyKing County
StateWashington
Coordinates47.5975, -122.32917
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48 US tons
Inventory rating29 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans67
Design loadH 20
Structure length1,178 ft (359.1 m)
Longest span31 ft (9.4 m)
Deck width45 ft (13.7 m)
Roadway width29 ft (8.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,500 (2019)
Projected traffic16,470 by 2039
Trucks5%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesRailroad
Detour if closed—
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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$16.8 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was 4th Ave S over Railroad Station built?

It was built in 1910, making it 115 years old in 2025. It was reconstructed in 1981.

What condition is 4th Ave S over Railroad Station 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 4th Ave S over Railroad Station carry?

About 13,500 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is 4th Ave S over Railroad Station?

The structure is 1,178 ft (359.1 m) long with a longest span of 31 ft (9.4 m) and a deck 45 ft wide.

Who owns 4th Ave S over Railroad Station?

It is owned by the City or Municipal Highway Agency.