US Bridges

Or 18 (hwy 39) over South Yamhill River

Fair

Yamhill County, Oregon · 159 MI E Polk Yam CO LN · Structure no. 08490 039 04563

Built
1963
62 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
324 ft
1 main span
Daily traffic
15,252
2022 count
Owner
State
State Highway Agency

About this bridge

Or 18 (hwy 39) over South Yamhill River is a steel stringer/multi-beam or girder carrying Or 18 (hwy 39) over South Yamhill River in Yamhill County, Oregon. It was built in 1963, so it is 62 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 15,252 vehicles a day, roughly 3% of them trucks, projected to reach 21,300 by 2042. The structure is 324 ft (98.8 m) long and 35 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesOr 18 (hwy 39)
CrossesSouth Yamhill River
Location159 MI E Polk Yam CO LN
RouteState Highway 18
CountyYamhill County
StateOregon
Coordinates45.19661, -123.18641
Functional classUrban Other Principal 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
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
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30 US tons
Inventory rating23.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+5 approach)
Design loadHS 20
Structure length324 ft (98.8 m)
Longest span110 ft (33.5 m)
Deck width35 ft (10.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,252 (2022)
Projected traffic21,300 by 2042
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 Or 18 (hwy 39) over South Yamhill River built?

It was built in 1963, making it 62 years old in 2025.

What condition is Or 18 (hwy 39) over South Yamhill River 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 November 2024.

How much traffic does Or 18 (hwy 39) over South Yamhill River carry?

About 15,252 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is Or 18 (hwy 39) over South Yamhill River?

The structure is 324 ft (98.8 m) long with a longest span of 110 ft (33.5 m) and a deck 35 ft wide.

Who owns Or 18 (hwy 39) over South Yamhill River?

It is owned by the State Highway Agency.