US Bridges

HWY 164 over Santiam River Oflow

Fair

Linn County, Oregon · 005 MI E Marion Linn CO L · Structure no. 18876 164 00673

Built
2001
24 years old
Condition
Fair
inspected July 2023
Type
Slab
Prestressed Concrete
Length
233 ft
4 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 2001, so it is 24 years old, younger 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.

It carries about 7,541 vehicles a day, roughly 9% of them trucks, projected to reach 10,200 by 2042. The structure is 233 ft (71 m) long and 40 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
Location005 MI E Marion Linn CO L
RouteState Highway 164
CountyLinn County
StateOregon
Coordinates44.71228, -123.02322
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 alignment8: Equal to present desirable criteria
Operating rating74.3 US tons
Inventory rating57.1 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHL 93
Structure length233 ft (71 m)
Longest span58 ft (17.7 m)
Deck width40 ft (12.2 m)
Roadway width37 ft (11.4 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was HWY 164 over Santiam River Oflow built?

It was built in 2001, making it 24 years old in 2025.

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 233 ft (71 m) long with a longest span of 58 ft (17.7 m) and a deck 40 ft wide.

Who owns HWY 164 over Santiam River Oflow?

It is owned by the State Highway Agency.