US Bridges

I-5 over Newaukum River

Fair

Lewis County, Washington · 1.2 N JCT SR 508 · Structure no. 0004204A0000000

Built
1952
73 years old, rebuilt 1976
Condition
Fair
inspected September 2024
Type
Tee Beam
Concrete Continuous
Length
284 ft
5 main spans
Daily traffic
29,186
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over Newaukum River is a concrete continuous tee beam carrying I-5 over Newaukum River in Lewis County, Washington. It was built in 1952 and reconstructed in 1976, so it is 73 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 29,186 vehicles a day, roughly 21% of them trucks, projected to reach 38,177 by 2039. The structure is 284 ft (86.6 m) long and 39 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI-5
CrossesNewaukum River
Location1.2 N JCT SR 508
RouteInterstate 5
Coordinates46.59811, -122.90181
Functional classUrban Principal Arterial - Interstate

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27.9 US tons
Inventory rating21.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length284 ft (86.6 m)
Longest span90 ft (27.4 m)
Deck width39 ft (12 m)
Roadway width36 ft (11.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic29,186 (2023)
Projected traffic38,177 by 2039
Trucks21%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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$5.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-5 over Newaukum River built?

It was built in 1952, making it 73 years old in 2025. It was reconstructed in 1976.

What condition is I-5 over Newaukum River 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 September 2024.

How much traffic does I-5 over Newaukum River carry?

About 29,186 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is I-5 over Newaukum River?

The structure is 284 ft (86.6 m) long with a longest span of 90 ft (27.4 m) and a deck 39 ft wide.

Who owns I-5 over Newaukum River?

It is owned by the State Highway Agency.