US Bridges

Upper Preston RD over Raging River

Fair

King County, Washington · 0.2 MI N of I-90 · Structure no. 084460000000000

Built
1974
51 years old
Condition
Fair
inspected March 2023
Type
Box Beam or Girders - Single or Spread
Concrete Continuous
Length
316 ft
3 main spans
Daily traffic
1,138
2020 count
Owner
County
County Highway Agency

About this bridge

Upper Preston RD over Raging River is a concrete continuous box beam or girders - single or spread carrying Upper Preston RD over Raging River in King County, Washington. It was built in 1974, so it is 51 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 5 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 1,138 vehicles a day, roughly 5% of them trucks, projected to reach 1,450 by 2040. The structure is 316 ft (96.3 m) long and 31 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesUpper Preston RD
CrossesRaging River
Location0.2 MI N of I-90
RouteCounty Highway 82780
CountyKing County
StateWashington
Coordinates47.51956, -121.92589
Functional classRural Local

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating41.4 US tons
Inventory rating32.2 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length316 ft (96.3 m)
Longest span146 ft (44.5 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,138 (2020)
Projected traffic1,450 by 2040
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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$11.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Upper Preston RD over Raging River built?

It was built in 1974, making it 51 years old in 2025.

What condition is Upper Preston RD over Raging River 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 March 2023.

How much traffic does Upper Preston RD over Raging River carry?

About 1,138 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is Upper Preston RD over Raging River?

The structure is 316 ft (96.3 m) long with a longest span of 146 ft (44.5 m) and a deck 31 ft wide.

Who owns Upper Preston RD over Raging River?

It is owned by the County Highway Agency.