US Bridges

SW Osage ST over B-35 Semi-Viaduct

FairPosted for load

Multnomah County, Oregon · W of SW Vista Ave · Structure no. 25B35 000

Built
1930
95 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Concrete Continuous
Length
175 ft
12 main spans
Daily traffic
107
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

SW Osage ST over B-35 Semi-Viaduct is a concrete continuous stringer/multi-beam or girder carrying SW Osage ST over B-35 Semi-Viaduct in Multnomah County, Oregon. It was built in 1930, so it is 95 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 5 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 load restriction.

It carries about 107 vehicles a day, roughly 1% of them trucks, projected to reach 118 by 2025. The structure is 175 ft (53.3 m) long and 9 ft wide.

Location

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CarriesSW Osage ST
CrossesB-35 Semi-Viaduct
LocationW of SW Vista Ave
RouteCity Street C0000
CountyMultnomah County
StateOregon
Coordinates45.52312, -122.69963
Functional classUrban Local

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30.8 US tons
Inventory rating23.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans12
Design loadH 15
Structure length175 ft (53.3 m)
Longest span15 ft (4.6 m)
Deck width9 ft (2.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic107 (2020)
Projected traffic118 by 2025
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SW Osage ST over B-35 Semi-Viaduct built?

It was built in 1930, making it 95 years old in 2025.

What condition is SW Osage ST over B-35 Semi-Viaduct 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 September 2024.

How much traffic does SW Osage ST over B-35 Semi-Viaduct carry?

About 107 vehicles per day (2020 count), of which roughly 1% are trucks.

How long is SW Osage ST over B-35 Semi-Viaduct?

The structure is 175 ft (53.3 m) long with a longest span of 15 ft (4.6 m) and a deck 9 ft wide.

Who owns SW Osage ST over B-35 Semi-Viaduct?

It is owned by the City or Municipal Highway Agency.