US Bridges

Thomas Road over Naneum Creek

FairPosted for load

Kittitas County, Washington · 00.57 W Naneum Road · Structure no. 084348000000000

Built
1955
70 years old, rebuilt 1960
Condition
Fair
inspected November 2024
Type
Channel Beam
Concrete Continuous
Length
35 ft
1 main span
Daily traffic
308
2023 count
Owner
County
County Highway Agency

About this bridge

Thomas Road over Naneum Creek is a concrete continuous channel beam carrying Thomas Road over Naneum Creek in Kittitas County, Washington. It was built in 1955 and reconstructed in 1960, so it is 70 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 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 308 vehicles a day, roughly 21% of them trucks, projected to reach 816 by 2043. The structure is 35 ft (10.7 m) long and 26 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesThomas Road
CrossesNaneum Creek
Location00.57 W Naneum Road
RouteCounty Highway 43132
CountyKittitas County
StateWashington
Coordinates47.09184, -120.47759
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
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 rating24 US tons
Inventory rating18 US tons

Structure

Structure typeChannel Beam
MaterialConcrete Continuous
DeckOther
Main spans1
Design loadH 20
Structure length35 ft (10.7 m)
Longest span33 ft (10.1 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic308 (2023)
Projected traffic816 by 2043
Trucks21%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 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$1.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Thomas Road over Naneum Creek built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 1960.

What condition is Thomas Road over Naneum 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 November 2024.

How much traffic does Thomas Road over Naneum Creek carry?

About 308 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is Thomas Road over Naneum Creek?

The structure is 35 ft (10.7 m) long with a longest span of 33 ft (10.1 m) and a deck 26 ft wide.

Who owns Thomas Road over Naneum Creek?

It is owned by the County Highway Agency.