US Bridges

SR 520 over NE 24th ST

Fair

King County, Washington · 1.9 E JCT I-405 · Structure no. 0014849B0000000

Built
1998
27 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
330 ft
3 main spans
Daily traffic
45,466
2023 count
Owner
State
State Highway Agency

About this bridge

SR 520 over NE 24th ST is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 520 over NE 24th ST in King County, Washington. It was built in 1998, so it is 27 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 45,466 vehicles a day, roughly 3% of them trucks, projected to reach 74,202 by 2039. The structure is 330 ft (100.6 m) long and 82 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 520
CrossesNE 24th ST
Location1.9 E JCT I-405
RouteState Highway 520
CountyKing County
StateWashington
Coordinates47.63123, -122.14887
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72 US tons
Inventory rating43 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length330 ft (100.6 m)
Longest span109 ft (33.2 m)
Deck width82 ft (25 m)
Roadway width80 ft (24.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic45,466 (2023)
Projected traffic74,202 by 2039
Trucks3%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 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$12.9 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 520 over NE 24th ST built?

It was built in 1998, making it 27 years old in 2025.

What condition is SR 520 over NE 24th ST 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 2023.

How much traffic does SR 520 over NE 24th ST carry?

About 45,466 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is SR 520 over NE 24th ST?

The structure is 330 ft (100.6 m) long with a longest span of 109 ft (33.2 m) and a deck 82 ft wide.

Who owns SR 520 over NE 24th ST?

It is owned by the State Highway Agency.