US Bridges

NE 8th ST over I-405

Good

King County, Washington · 2.7 N JCT I-90 · Structure no. 0016317A0000000

Built
2003
22 years old
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
328 ft
2 main spans
Daily traffic
48,783
2009 count
Owner
State
State Highway Agency

About this bridge

NE 8th ST over I-405 is a steel stringer/multi-beam or girder carrying NE 8th ST over I-405 in King County, Washington. It was built in 2003, so it is 22 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 48,783 vehicles a day, roughly 6% of them trucks, projected to reach 81,712 by 2036. The structure is 328 ft (100 m) long and 121 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesNE 8th ST
CrossesI-405
Location2.7 N JCT I-90
RouteCity Street 405
CountyKing County
StateWashington
Coordinates47.61736, -122.18939
Functional classUrban Other Principal Arterial

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 inspectionAugust 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 rating66 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length328 ft (100 m)
Longest span164 ft (50 m)
Deck width121 ft (37 m)
Roadway width103 ft (31.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic48,783 (2009)
Projected traffic81,712 by 2036
Trucks6%
Lanes on structure9
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$16.4 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was NE 8th ST over I-405 built?

It was built in 2003, making it 22 years old in 2025.

What condition is NE 8th ST over I-405 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 August 2023.

How much traffic does NE 8th ST over I-405 carry?

About 48,783 vehicles per day (2009 count), of which roughly 6% are trucks.

How long is NE 8th ST over I-405?

The structure is 328 ft (100 m) long with a longest span of 164 ft (50 m) and a deck 121 ft wide.

Who owns NE 8th ST over I-405?

It is owned by the State Highway Agency.