US Bridges

I-5 over SR 503

Fair

Cowlitz County, Washington · 0.4 N Clark CO · Structure no. 0007064B0000000

Built
1963
62 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
168 ft
3 main spans
Daily traffic
33,156
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over SR 503 is a prestressed concrete stringer/multi-beam or girder carrying I-5 over SR 503 in Cowlitz County, Washington. It was built in 1963, so it is 62 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 33,156 vehicles a day, roughly 15% of them trucks, projected to reach 43,558 by 2039. The structure is 168 ft (51.2 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-5
CrossesSR 503
Location0.4 N Clark CO
RouteInterstate 5
CountyCowlitz County
StateWashington
Coordinates45.90547, -122.74239
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating77.9 US tons
Inventory rating46 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length168 ft (51.2 m)
Longest span82 ft (25 m)
Deck width48 ft (14.6 m)
Roadway width45 ft (13.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic33,156 (2023)
Projected traffic43,558 by 2039
Trucks15%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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$4.5 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over SR 503 built?

It was built in 1963, making it 62 years old in 2025.

What condition is I-5 over SR 503 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 October 2023.

How much traffic does I-5 over SR 503 carry?

About 33,156 vehicles per day (2023 count), of which roughly 15% are trucks.

How long is I-5 over SR 503?

The structure is 168 ft (51.2 m) long with a longest span of 82 ft (25 m) and a deck 48 ft wide.

Who owns I-5 over SR 503?

It is owned by the State Highway Agency.