US Bridges

I-5 over Bn RY

Fair

Cowlitz County, Washington · 4.9 N JCT SR 503 · Structure no. 0008952D0000000

Built
1972
53 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
384 ft
3 main spans
Daily traffic
37,599
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over Bn RY is a steel continuous stringer/multi-beam or girder carrying I-5 over Bn RY in Cowlitz County, Washington. It was built in 1972, so it is 53 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 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 37,599 vehicles a day, roughly 18% of them trucks, projected to reach 48,637 by 2039. The structure is 384 ft (117 m) long and 54 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesI-5
CrossesBn RY
Location4.9 N JCT SR 503
RouteInterstate 5
CountyCowlitz County
StateWashington
Coordinates45.95944, -122.80589
Functional classRural 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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length384 ft (117 m)
Longest span190 ft (57.9 m)
Deck width54 ft (16.6 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic37,599 (2023)
Projected traffic48,637 by 2039
Trucks18%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed11.2 mi (18 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$9.9 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over Bn RY built?

It was built in 1972, making it 53 years old in 2025.

What condition is I-5 over Bn RY 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 2023.

How much traffic does I-5 over Bn RY carry?

About 37,599 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is I-5 over Bn RY?

The structure is 384 ft (117 m) long with a longest span of 190 ft (57.9 m) and a deck 54 ft wide.

Who owns I-5 over Bn RY?

It is owned by the State Highway Agency.