US Bridges

Or 99W (hwy 91) over Whiteson Dip

Fair

Yamhill County, Oregon · 020 MI N Amity · Structure no. 08208 01W 04218

Built
1956
69 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
275 ft
11 main spans
Daily traffic
9,298
2022 count
Owner
State
State Highway Agency

About this bridge

Or 99W (hwy 91) over Whiteson Dip is a concrete stringer/multi-beam or girder carrying Or 99W (hwy 91) over Whiteson Dip in Yamhill County, Oregon. It was built in 1956, so it is 69 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 9,298 vehicles a day, roughly 5% of them trucks, projected to reach 9,400 by 2042. The structure is 275 ft (83.8 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 99W (hwy 91)
CrossesWhiteson Dip
Location020 MI N Amity
RouteState Highway 99
CountyYamhill County
StateOregon
Coordinates45.14947, -123.1974
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to 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 rating86 US tons
Inventory rating52 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans11
Design loadHS 20
Structure length275 ft (83.8 m)
Longest span25 ft (7.6 m)
Deck width35 ft (10.6 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,298 (2022)
Projected traffic9,400 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Or 99W (hwy 91) over Whiteson Dip built?

It was built in 1956, making it 69 years old in 2025.

What condition is Or 99W (hwy 91) over Whiteson Dip 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) over Whiteson Dip carry?

About 9,298 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is Or 99W (hwy 91) over Whiteson Dip?

The structure is 275 ft (83.8 m) long with a longest span of 25 ft (7.6 m) and a deck 35 ft wide.

Who owns Or 99W (hwy 91) over Whiteson Dip?

It is owned by the State Highway Agency.