US Bridges

Union FLAT/9020 over Union Flat Creek

Fair

Whitman County, Washington · 4.63 MI SE Wawawai-Pullmn · Structure no. 082557000000000

Built
1963
62 years old
Condition
Fair
inspected January 2025
Type
Tee Beam
Prestressed Concrete
Length
97 ft
1 main span
Daily traffic
34
2021 count
Owner
County
County Highway Agency

About this bridge

Union FLAT/9020 over Union Flat Creek is a prestressed concrete tee beam carrying Union FLAT/9020 over Union Flat Creek in Whitman County, Washington. It was built in 1963, so it is 62 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.

It carries about 34 vehicles a day, roughly 25% of them trucks, projected to reach 35 by 2042. The structure is 97 ft (29.6 m) long and 24 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesUnion FLAT/9020
CrossesUnion Flat Creek
Location4.63 MI SE Wawawai-Pullmn
RouteCounty Highway 90200
CountyWhitman County
StateWashington
Coordinates46.6002, -117.19938
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to 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 alignment6: Equal to present minimum criteria
Operating rating44 US tons
Inventory rating33.6 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 15
Structure length97 ft (29.6 m)
Longest span95 ft (29 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34 (2021)
Projected traffic35 by 2042
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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$3.9 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Union FLAT/9020 over Union Flat Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is Union FLAT/9020 over Union Flat 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 January 2025.

How much traffic does Union FLAT/9020 over Union Flat Creek carry?

About 34 vehicles per day (2021 count), of which roughly 25% are trucks.

How long is Union FLAT/9020 over Union Flat Creek?

The structure is 97 ft (29.6 m) long with a longest span of 95 ft (29 m) and a deck 24 ft wide.

Who owns Union FLAT/9020 over Union Flat Creek?

It is owned by the County Highway Agency.