US Bridges

HWY 164 over Santiam River Oflow

FairPosted for load

Linn County, Oregon · 007 MI E Marion Linn CO L · Structure no. 00360A164 00698

Built
1960
65 years old, rebuilt 1965
Condition
Fair
inspected July 2023
Type
Slab
Prestressed Concrete
Length
473 ft
19 main spans
Daily traffic
7,541
2022 count
Owner
State
State Highway Agency

About this bridge

HWY 164 over Santiam River Oflow is a prestressed concrete slab carrying HWY 164 over Santiam River Oflow in Linn County, Oregon. It was built in 1960 and reconstructed in 1965, so it is 65 years old, older than the Oregon average of 49.9 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 other load-capacity restriction.

It carries about 7,541 vehicles a day, roughly 9% of them trucks, projected to reach 10,200 by 2042. The structure is 473 ft (144.2 m) long and 30 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesHWY 164
CrossesSantiam River Oflow
Location007 MI E Marion Linn CO L
RouteState Highway 164
CountyLinn County
StateOregon
Coordinates44.71087, -123.02777
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusPosted for other load-capacity 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.3 US tons
Inventory rating22.5 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans19
Design loadHS 20
Structure length473 ft (144.2 m)
Longest span25 ft (7.6 m)
Deck width30 ft (9 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,541 (2022)
Projected traffic10,200 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$2.4 million
NavigationNo navigation control on waterway

Frequently asked questions

When was HWY 164 over Santiam River Oflow built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 1965.

What condition is HWY 164 over Santiam River Oflow 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 July 2023.

How much traffic does HWY 164 over Santiam River Oflow carry?

About 7,541 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is HWY 164 over Santiam River Oflow?

The structure is 473 ft (144.2 m) long with a longest span of 25 ft (7.6 m) and a deck 30 ft wide.

Who owns HWY 164 over Santiam River Oflow?

It is owned by the State Highway Agency.