US Bridges

SR 504 over I-5

Fair

Cowlitz County, Washington · JCT I-5 · Structure no. 0009580D0000000

Built
1975
50 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
291 ft
2 main spans
Daily traffic
9,416
2023 count
Owner
State
State Highway Agency

About this bridge

SR 504 over I-5 is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 504 over I-5 in Cowlitz County, Washington. It was built in 1975, so it is 50 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 9,416 vehicles a day, roughly 6% of them trucks, projected to reach 12,256 by 2039. The structure is 291 ft (88.7 m) long and 59 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR 504
CrossesI-5
LocationJCT I-5
RouteState Highway 504
CountyCowlitz County
StateWashington
Coordinates46.28425, -122.90308
Functional classRural Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionJuly 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 rating80 US tons
Inventory rating47 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length291 ft (88.7 m)
Longest span141 ft (43 m)
Deck width59 ft (18 m)
Roadway width56 ft (17.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,416 (2023)
Projected traffic12,256 by 2039
Trucks6%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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$8 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 504 over I-5 built?

It was built in 1975, making it 50 years old in 2025.

What condition is SR 504 over I-5 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 SR 504 over I-5 carry?

About 9,416 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 504 over I-5?

The structure is 291 ft (88.7 m) long with a longest span of 141 ft (43 m) and a deck 59 ft wide.

Who owns SR 504 over I-5?

It is owned by the State Highway Agency.