US Bridges

428th Ave SE over Middle Fork Snoqualmie R

Good

King County, Washington · 2.1 MI E of SR 202 · Structure no. 084602000000000

Built
1984
41 years old
Condition
Good
inspected March 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
393 ft
1 main span
Daily traffic
1,226
2020 count
Owner
County
County Highway Agency

About this bridge

428th Ave SE over Middle Fork Snoqualmie R is a prestressed concrete continuous box beam or girders - multiple carrying 428th Ave SE over Middle Fork Snoqualmie R in King County, Washington. It was built in 1984, so it is 41 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 1,226 vehicles a day, roughly 5% of them trucks, projected to reach 1,650 by 2040. The structure is 393 ft (119.8 m) long and 33 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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Carries428th Ave SE
CrossesMiddle Fork Snoqualmie R
Location2.1 MI E of SR 202
RouteCounty Highway 87150
CountyKing County
StateWashington
Coordinates47.51592, -121.76982
Functional classRural Minor Collector

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 inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating84.3 US tons
Inventory rating65 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadH 20
Structure length393 ft (119.8 m)
Longest span210 ft (64 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,226 (2020)
Projected traffic1,650 by 2040
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$14.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 428th Ave SE over Middle Fork Snoqualmie R built?

It was built in 1984, making it 41 years old in 2025.

What condition is 428th Ave SE over Middle Fork Snoqualmie R 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 March 2023.

How much traffic does 428th Ave SE over Middle Fork Snoqualmie R carry?

About 1,226 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is 428th Ave SE over Middle Fork Snoqualmie R?

The structure is 393 ft (119.8 m) long with a longest span of 210 ft (64 m) and a deck 33 ft wide.

Who owns 428th Ave SE over Middle Fork Snoqualmie R?

It is owned by the County Highway Agency.