US Bridges

Madison ST over I-5

Fair

King County, Washington · 1.1 N JCT I-90 · Structure no. 0007110C0000000

Built
1964
61 years old
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
280 ft
3 main spans
Daily traffic
30,000
2018 count
Owner
State
State Highway Agency

About this bridge

Madison ST over I-5 is a concrete continuous box beam or girders - multiple carrying Madison ST over I-5 in King County, Washington. It was built in 1964, so it is 61 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 30,000 vehicles a day, roughly 5% of them trucks, projected to reach 40,000 by 2039. The structure is 280 ft (85.3 m) long and 76 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesMadison ST
CrossesI-5
Location1.1 N JCT I-90
RouteCity Street 0
CountyKing County
StateWashington
Coordinates47.60706, -122.33064
Functional classUrban Other Principal 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 inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating19.6 US tons
Inventory rating15.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length280 ft (85.3 m)
Longest span104 ft (31.7 m)
Deck width76 ft (23.1 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30,000 (2018)
Projected traffic40,000 by 2039
Trucks5%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

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$6.7 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Madison ST over I-5 built?

It was built in 1964, making it 61 years old in 2025.

What condition is Madison ST 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 September 2023.

How much traffic does Madison ST over I-5 carry?

About 30,000 vehicles per day (2018 count), of which roughly 5% are trucks.

How long is Madison ST over I-5?

The structure is 280 ft (85.3 m) long with a longest span of 104 ft (31.7 m) and a deck 76 ft wide.

Who owns Madison ST over I-5?

It is owned by the State Highway Agency.