US Bridges

SR 31 over Pend Oreille River

Fair

Pend Oreille County, Washington · 14.1 N JCT SR 20 · Structure no. 0003749A0000000

Built
1950
75 years old
Condition
Fair
inspected August 2024
Type
Truss - Deck
Steel Continuous
Length
696 ft
3 main spans
Daily traffic
1,288
2023 count
Owner
State
State Highway Agency

About this bridge

SR 31 over Pend Oreille River is a steel continuous truss - deck carrying SR 31 over Pend Oreille River in Pend Oreille 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 1,288 vehicles a day, roughly 13% of them trucks, projected to reach 1,587 by 2039. The structure is 696 ft (212.1 m) long and 34 ft wide. If it were closed, the detour would be 21.7 mi (35 km).

Location

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CarriesSR 31
CrossesPend Oreille River
Location14.1 N JCT SR 20
RouteState Highway 31
CountyPend Oreille County
StateWashington
Coordinates48.86596, -117.37396
Functional classRural Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 rating44 US tons
Inventory rating26 US tons

Structure

Structure typeTruss - Deck
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+4 approach)
Design loadHS 20
Structure length696 ft (212.1 m)
Longest span240 ft (73.2 m)
Deck width34 ft (10.3 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,288 (2023)
Projected traffic1,587 by 2039
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed21.7 mi (35 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$11.2 million (2022 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was SR 31 over Pend Oreille River built?

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

What condition is SR 31 over Pend Oreille 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 August 2024.

How much traffic does SR 31 over Pend Oreille River carry?

About 1,288 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is SR 31 over Pend Oreille River?

The structure is 696 ft (212.1 m) long with a longest span of 240 ft (73.2 m) and a deck 34 ft wide.

Who owns SR 31 over Pend Oreille River?

It is owned by the State Highway Agency.