US Bridges

I-5 over SR 507 Mellen ST

Fair

Lewis County, Washington · 3.7 N JCT SR 6 · Structure no. 0003922A0000000

Built
1951
74 years old, rebuilt 1972
Condition
Fair
inspected June 2024
Type
Tee Beam
Concrete Continuous
Length
94 ft
3 main spans
Daily traffic
32,590
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over SR 507 Mellen ST is a concrete continuous tee beam carrying I-5 over SR 507 Mellen ST in Lewis County, Washington. It was built in 1951 and reconstructed in 1972, so it is 74 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 32,590 vehicles a day, roughly 17% of them trucks, projected to reach 38,114 by 2039. The structure is 94 ft (28.7 m) long and 85 ft wide.

Location

Open in Google Maps
CarriesI-5
CrossesSR 507 Mellen ST
Location3.7 N JCT SR 6
RouteInterstate 5
CountyLewis County
StateWashington
Coordinates46.71174, -122.9755
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating84 US tons
Inventory rating50 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length94 ft (28.7 m)
Longest span36 ft (11 m)
Deck width85 ft (25.9 m)
Roadway width78 ft (23.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic32,590 (2023)
Projected traffic38,114 by 2039
Trucks17%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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$3.8 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over SR 507 Mellen ST built?

It was built in 1951, making it 74 years old in 2025. It was reconstructed in 1972.

What condition is I-5 over SR 507 Mellen ST 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 June 2024.

How much traffic does I-5 over SR 507 Mellen ST carry?

About 32,590 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is I-5 over SR 507 Mellen ST?

The structure is 94 ft (28.7 m) long with a longest span of 36 ft (11 m) and a deck 85 ft wide.

Who owns I-5 over SR 507 Mellen ST?

It is owned by the State Highway Agency.