US Bridges

Upper Preston RD over Lake Creek

Fair

King County, Washington · 1.8 MI SE of I-90 · Structure no. 080024000000000

Built
1950
75 years old
Condition
Fair
inspected May 2024
Type
Channel Beam
Concrete
Length
60 ft
3 main spans
Daily traffic
1,112
2019 count
Owner
County
County Highway Agency

About this bridge

Upper Preston RD over Lake Creek is a concrete channel beam carrying Upper Preston RD over Lake Creek in King County, Washington. It was built in 1950, so it is 75 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 1,112 vehicles a day, roughly 1% of them trucks, projected to reach 2,010 by 2039. The structure is 60 ft (18.3 m) long and 24 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesUpper Preston RD
CrossesLake Creek
Location1.8 MI SE of I-90
RouteCounty Highway 86050
CountyKing County
StateWashington
Coordinates47.50381, -121.90408
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.2 US tons
Inventory rating23.6 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadHS 15
Structure length60 ft (18.3 m)
Longest span20 ft (6.1 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,112 (2019)
Projected traffic2,010 by 2039
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Upper Preston RD over Lake Creek built?

It was built in 1950, making it 75 years old in 2025.

What condition is Upper Preston RD over Lake Creek 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 May 2024.

How much traffic does Upper Preston RD over Lake Creek carry?

About 1,112 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is Upper Preston RD over Lake Creek?

The structure is 60 ft (18.3 m) long with a longest span of 20 ft (6.1 m) and a deck 24 ft wide.

Who owns Upper Preston RD over Lake Creek?

It is owned by the County Highway Agency.