US Bridges

I-5 over Norfolk ST Sewer

Fair

King County, Washington · 1.0 N JCT SR 900 · Structure no. 0007617A0000000

Built
1966
59 years old, rebuilt 1991
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
65 ft
1 main span
Daily traffic
103,312
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over Norfolk ST Sewer is a prestressed concrete stringer/multi-beam or girder carrying I-5 over Norfolk ST Sewer in King County, Washington. It was built in 1966 and reconstructed in 1991, so it is 59 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 103,312 vehicles a day, roughly 7% of them trucks, projected to reach 154,285 by 2039. The structure is 65 ft (19.7 m) long and 83 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-5
CrossesNorfolk ST Sewer
Location1.0 N JCT SR 900
RouteInterstate 5
CountyKing County
StateWashington
Coordinates47.51348, -122.28567
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating21.8 US tons
Inventory rating16.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length65 ft (19.7 m)
Longest span60 ft (18.3 m)
Deck width83 ft (25.4 m)
Roadway width79 ft (24.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic103,312 (2023)
Projected traffic154,285 by 2039
Trucks7%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesOther
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$2.5 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over Norfolk ST Sewer built?

It was built in 1966, making it 59 years old in 2025. It was reconstructed in 1991.

What condition is I-5 over Norfolk ST Sewer 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 2024.

How much traffic does I-5 over Norfolk ST Sewer carry?

About 103,312 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is I-5 over Norfolk ST Sewer?

The structure is 65 ft (19.7 m) long with a longest span of 60 ft (18.3 m) and a deck 83 ft wide.

Who owns I-5 over Norfolk ST Sewer?

It is owned by the State Highway Agency.