US Bridges

US 12 over Alpowa CR

Fair

Asotin County, Washington · 3.0 E Garfield CO · Structure no. 0009660A0000000

Built
1975
50 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
213 ft
2 main spans
Daily traffic
3,159
2023 count
Owner
State
State Highway Agency

About this bridge

US 12 over Alpowa CR is a prestressed concrete continuous stringer/multi-beam or girder carrying US 12 over Alpowa CR in Asotin County, Washington. It was built in 1975, so it is 50 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 3,159 vehicles a day, roughly 15% of them trucks, projected to reach 3,142 by 2039. The structure is 213 ft (64.9 m) long and 43 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesUS 12
CrossesAlpowa CR
Location3.0 E Garfield CO
RouteU.S. Route 12
CountyAsotin County
StateWashington
Coordinates46.41186, -117.21403
Functional classRural Principal Arterial - Other

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
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 evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length213 ft (64.9 m)
Longest span104 ft (31.7 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,159 (2023)
Projected traffic3,142 by 2039
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$4.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 12 over Alpowa CR built?

It was built in 1975, making it 50 years old in 2025.

What condition is US 12 over Alpowa CR 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 US 12 over Alpowa CR carry?

About 3,159 vehicles per day (2023 count), of which roughly 15% are trucks.

How long is US 12 over Alpowa CR?

The structure is 213 ft (64.9 m) long with a longest span of 104 ft (31.7 m) and a deck 43 ft wide.

Who owns US 12 over Alpowa CR?

It is owned by the State Highway Agency.