US Bridges

I-5 (hwy 1) NB over Knox Butte Road

Fair

Linn County, Oregon · 001 MI N Albany · Structure no. 08221A001 23423

Built
1958
67 years old
Condition
Fair
inspected January 2023
Type
Tee Beam
Concrete Continuous
Length
125 ft
3 main spans
Daily traffic
34,103
2022 count
Owner
State
State Highway Agency

About this bridge

I-5 (hwy 1) NB over Knox Butte Road is a concrete continuous tee beam carrying I-5 (hwy 1) NB over Knox Butte Road in Linn County, Oregon. It was built in 1958, so it is 67 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.

It carries about 34,103 vehicles a day, roughly 15% of them trucks, projected to reach 45,500 by 2042. The structure is 125 ft (38.1 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-5 (hwy 1) NB
CrossesKnox Butte Road
Location001 MI N Albany
RouteInterstate 5
CountyLinn County
StateOregon
Coordinates44.64477, -123.06233
Functional classUrban Principal Arterial - Interstate

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating33 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length125 ft (38.1 m)
Longest span49 ft (14.9 m)
Deck width45 ft (13.7 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34,103 (2022)
Projected traffic45,500 by 2042
Trucks15%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 (hwy 1) NB over Knox Butte Road built?

It was built in 1958, making it 67 years old in 2025.

What condition is I-5 (hwy 1) NB over Knox Butte Road 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 January 2023.

How much traffic does I-5 (hwy 1) NB over Knox Butte Road carry?

About 34,103 vehicles per day (2022 count), of which roughly 15% are trucks.

How long is I-5 (hwy 1) NB over Knox Butte Road?

The structure is 125 ft (38.1 m) long with a longest span of 49 ft (14.9 m) and a deck 45 ft wide.

Who owns I-5 (hwy 1) NB over Knox Butte Road?

It is owned by the State Highway Agency.