US Bridges

Spokane ST Viaduct over E Marginal Wy 1st 4th

Good

King County, Washington · S Spokane ST & E Marginal · Structure no. 089348000000000

Built
2012
13 years old
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Concrete Continuous
Length
3,332 ft
5 main spans
Daily traffic
42,350
2021 count
Owner
City
City or Municipal Highway Agency

About this bridge

Spokane ST Viaduct over E Marginal Wy 1st 4th is a concrete continuous stringer/multi-beam or girder carrying Spokane ST Viaduct over E Marginal Wy 1st 4th in King County, Washington. It was built in 2012, so it is 13 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 42,350 vehicles a day, roughly 10% of them trucks, projected to reach 44,467 by 2030. The structure is 3,332 ft (1,015.6 m) long and 26 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSpokane ST Viaduct
CrossesE Marginal Wy 1st 4th
LocationS Spokane ST & E Marginal
RouteCity Street 1140
CountyKing County
StateWashington
Coordinates47.57172, -122.332
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating83 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5 (+66 approach)
Design loadHS 20
Structure length3,332 ft (1,015.6 m)
Longest span93 ft (28.4 m)
Deck width26 ft (7.9 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck16 ft (4.8 m)

Traffic and service

Average daily traffic42,350 (2021)
Projected traffic44,467 by 2030
Trucks10%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkSTRAHNET connector

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$80.7 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Spokane ST Viaduct over E Marginal Wy 1st 4th built?

It was built in 2012, making it 13 years old in 2025.

What condition is Spokane ST Viaduct over E Marginal Wy 1st 4th in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does Spokane ST Viaduct over E Marginal Wy 1st 4th carry?

About 42,350 vehicles per day (2021 count), of which roughly 10% are trucks.

How long is Spokane ST Viaduct over E Marginal Wy 1st 4th?

The structure is 3,332 ft (1,015.6 m) long with a longest span of 93 ft (28.4 m) and a deck 26 ft wide.

Who owns Spokane ST Viaduct over E Marginal Wy 1st 4th?

It is owned by the City or Municipal Highway Agency.