US Bridges

YOUNG/6170 over Alkali Creek

FairPosted for load

Whitman County, Washington · 2.89 MI SW Union Flat Crk · Structure no. 079955000000000

Built
1977
48 years old
Condition
Fair
inspected October 2024
Type
Tee Beam
Prestressed Concrete
Length
36 ft
1 main span
Daily traffic
174
2020 count
Owner
County
County Highway Agency

About this bridge

YOUNG/6170 over Alkali Creek is a prestressed concrete tee beam carrying YOUNG/6170 over Alkali Creek in Whitman County, Washington. It was built in 1977, so it is 48 years old, younger 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 174 vehicles a day, roughly 25% of them trucks, projected to reach 177 by 2039. The structure is 36 ft (11 m) long and 24 ft wide. If it were closed, the detour would be 26.1 mi (42 km).

Location

Open in Google Maps
CarriesYOUNG/6170
CrossesAlkali Creek
Location2.89 MI SW Union Flat Crk
RouteCounty Highway 61700
CountyWhitman County
StateWashington
Coordinates46.812, -117.64135
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.3 US tons
Inventory rating28.5 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length36 ft (11 m)
Longest span35 ft (10.7 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic174 (2020)
Projected traffic177 by 2039
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed26.1 mi (42 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$1.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was YOUNG/6170 over Alkali Creek built?

It was built in 1977, making it 48 years old in 2025.

What condition is YOUNG/6170 over Alkali 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 October 2024.

How much traffic does YOUNG/6170 over Alkali Creek carry?

About 174 vehicles per day (2020 count), of which roughly 25% are trucks.

How long is YOUNG/6170 over Alkali Creek?

The structure is 36 ft (11 m) long with a longest span of 35 ft (10.7 m) and a deck 24 ft wide.

Who owns YOUNG/6170 over Alkali Creek?

It is owned by the County Highway Agency.