US Bridges

SR 128 over Snake River

Fair

Asotin County, Washington · 0.2 E JCT US 12 · Structure no. 0010850A0000000

Built
1979
46 years old
Condition
Fair
inspected June 2024
Type
Box Beam or Girders - Multiple
Steel Continuous
Length
1,450 ft
5 main spans
Daily traffic
5,160
2023 count
Owner
State
State Highway Agency

About this bridge

SR 128 over Snake River is a steel continuous box beam or girders - multiple carrying SR 128 over Snake River in Asotin County, Washington. It was built in 1979, so it is 46 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.

It carries about 5,160 vehicles a day, roughly 13% of them trucks, projected to reach 5,790 by 2039. The structure is 1,450 ft (442 m) long and 39 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesSR 128
CrossesSnake River
Location0.2 E JCT US 12
RouteState Highway 128
CountyAsotin County
StateWashington
Coordinates46.423, -117.07036
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 alignment6: Equal to present minimum criteria
Operating rating63.9 US tons
Inventory rating41 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length1,450 ft (442 m)
Longest span420 ft (128 m)
Deck width39 ft (12 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,160 (2023)
Projected traffic5,790 by 2039
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway, waterway and railroad
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$23.4 million (2022 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was SR 128 over Snake River built?

It was built in 1979, making it 46 years old in 2025.

What condition is SR 128 over Snake 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 June 2024.

How much traffic does SR 128 over Snake River carry?

About 5,160 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is SR 128 over Snake River?

The structure is 1,450 ft (442 m) long with a longest span of 420 ft (128 m) and a deck 39 ft wide.

Who owns SR 128 over Snake River?

It is owned by the State Highway Agency.