US Bridges

SE 424th ST over Newaukum Creek

Fair

King County, Washington · 0.5 MI W of SR-169 · Structure no. 081694000000000

Built
1950
75 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Concrete
Length
40 ft
3 main spans
Daily traffic
1,500
2019 count
Owner
County
County Highway Agency

About this bridge

SE 424th ST over Newaukum Creek is a concrete stringer/multi-beam or girder carrying SE 424th ST over Newaukum Creek in King County, Washington. It was built in 1950, so it is 75 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 1,500 vehicles a day, roughly 2% of them trucks, projected to reach 2,250 by 2039. The structure is 40 ft (12.2 m) long and 29 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesSE 424th ST
CrossesNewaukum Creek
Location0.5 MI W of SR-169
RouteCounty Highway 31240
CountyKing County
StateWashington
Coordinates47.22101, -121.99785
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating20 US tons
Inventory rating15.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadHS 15
Structure length40 ft (12.2 m)
Longest span28 ft (8.5 m)
Deck width29 ft (8.8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,500 (2019)
Projected traffic2,250 by 2039
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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$1.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SE 424th ST over Newaukum Creek built?

It was built in 1950, making it 75 years old in 2025.

What condition is SE 424th ST over Newaukum 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 July 2024.

How much traffic does SE 424th ST over Newaukum Creek carry?

About 1,500 vehicles per day (2019 count), of which roughly 2% are trucks.

How long is SE 424th ST over Newaukum Creek?

The structure is 40 ft (12.2 m) long with a longest span of 28 ft (8.5 m) and a deck 29 ft wide.

Who owns SE 424th ST over Newaukum Creek?

It is owned by the County Highway Agency.