US Bridges

Sixth ST over North Fork Palouse River

Fair

Whitman County, Washington · 0.10 MI E SR 195 · Structure no. 085155000000000

Built
1920
105 years old, rebuilt 1970
Condition
Fair
inspected January 2025
Type
Arch - Deck
Concrete
Length
85 ft
1 main span
Daily traffic
300
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Sixth ST over North Fork Palouse River is a concrete arch - deck carrying Sixth ST over North Fork Palouse River in Whitman County, Washington. It was built in 1920 and reconstructed in 1970, so it is 105 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 300 vehicles a day, roughly 5% of them trucks, projected to reach 306 by 2042. The structure is 85 ft (25.9 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesSixth ST
CrossesNorth Fork Palouse River
Location0.10 MI E SR 195
RouteCity Street 230
Coordinates46.89585, -117.36062
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 protection8 Very GoodNo problems noted.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating28 US tons
Inventory rating17 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length85 ft (25.9 m)
Longest span75 ft (22.9 m)
Deck width28 ft (8.5 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic300 (2023)
Projected traffic306 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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$3.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Sixth ST over North Fork Palouse River built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1970.

What condition is Sixth ST over North Fork Palouse 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 January 2025.

How much traffic does Sixth ST over North Fork Palouse River carry?

About 300 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Sixth ST over North Fork Palouse River?

The structure is 85 ft (25.9 m) long with a longest span of 75 ft (22.9 m) and a deck 28 ft wide.

Who owns Sixth ST over North Fork Palouse River?

It is owned by the City or Municipal Highway Agency.