US Bridges

SR 900 over Wetlands

Good

King County, Washington · 8.4 E JCT I-405 · Structure no. 086743000000000

Built
2002
23 years old
Condition
Good
inspected June 2022
Type
Slab
Concrete
Length
50 ft
5 main spans
Daily traffic
11,002
2023 count
Owner
State
State Highway Agency

About this bridge

SR 900 over Wetlands is a concrete slab carrying SR 900 over Wetlands in King County, Washington. It was built in 2002, so it is 23 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 11,002 vehicles a day, roughly 4% of them trucks, projected to reach 33,791 by 2039. The structure is 50 ft (15.2 m) long and 16 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

CarriesSR 900
CrossesWetlands
Location8.4 E JCT I-405
RouteState Highway 900
Coordinates47.53108, -122.06181
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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans5
Design loadHS 25 or greater
Structure length50 ft (15.2 m)
Longest span15 ft (4.6 m)
Deck width16 ft (5 m)
Roadway width71 ft (21.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,002 (2023)
Projected traffic33,791 by 2039
Trucks4%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed14.9 mi (24 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$1.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 900 over Wetlands built?

It was built in 2002, making it 23 years old in 2025.

What condition is SR 900 over Wetlands 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 June 2022.

How much traffic does SR 900 over Wetlands carry?

About 11,002 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is SR 900 over Wetlands?

The structure is 50 ft (15.2 m) long with a longest span of 15 ft (4.6 m) and a deck 16 ft wide.

Who owns SR 900 over Wetlands?

It is owned by the State Highway Agency.