US Bridges

Or 99W (hwy 91) NB over North Yamhill River

Fair

Yamhill County, Oregon · 001 MI N Mcminnville · Structure no. 00441A01W 03504

Built
1959
66 years old
Condition
Fair
inspected April 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
382 ft
3 main spans
Daily traffic
10,193
2022 count
Owner
State
State Highway Agency

About this bridge

Or 99W (hwy 91) NB over North Yamhill River is a concrete continuous box beam or girders - multiple carrying Or 99W (hwy 91) NB over North Yamhill River in Yamhill County, Oregon. It was built in 1959, so it is 66 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 10,193 vehicles a day, roughly 16% of them trucks, projected to reach 12,400 by 2042. The structure is 382 ft (116.3 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 99W (hwy 91) NB
CrossesNorth Yamhill River
Location001 MI N Mcminnville
RouteState Highway 99
CountyYamhill County
StateOregon
Coordinates45.23158, -123.16098
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 inspectionApril 2023
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 rating30.8 US tons
Inventory rating23.6 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadHS 20
Structure length382 ft (116.3 m)
Longest span100 ft (30.5 m)
Deck width35 ft (10.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,193 (2022)
Projected traffic12,400 by 2042
Trucks16%
Lanes on structure2
Traffic directionOne-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 99W (hwy 91) NB over North Yamhill River built?

It was built in 1959, making it 66 years old in 2025.

What condition is Or 99W (hwy 91) NB over North 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 April 2023.

How much traffic does Or 99W (hwy 91) NB over North Yamhill River carry?

About 10,193 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is Or 99W (hwy 91) NB over North Yamhill River?

The structure is 382 ft (116.3 m) long with a longest span of 100 ft (30.5 m) and a deck 35 ft wide.

Who owns Or 99W (hwy 91) NB over North Yamhill River?

It is owned by the State Highway Agency.