US Bridges

Or 99W (hwy 91) over Luckiamute River

Fair

Polk County, Oregon · 044 MI S Mounmouth · Structure no. 06653A01W 06813

Built
1954
71 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Concrete Continuous
Length
302 ft
5 main spans
Daily traffic
9,582
2022 count
Owner
State
State Highway Agency

About this bridge

Or 99W (hwy 91) over Luckiamute River is a concrete continuous tee beam carrying Or 99W (hwy 91) over Luckiamute River in Polk County, Oregon. It was built in 1954, so it is 71 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.

It carries about 9,582 vehicles a day, roughly 6% of them trucks, projected to reach 10,000 by 2042. The structure is 302 ft (92 m) long and 35 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

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CarriesOr 99W (hwy 91)
CrossesLuckiamute River
Location044 MI S Mounmouth
RouteState Highway 99
CountyPolk County
StateOregon
Coordinates44.7805, -123.2292
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 evaluation4: Meets minimum tolerable limits to be 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 rating24.7 US tons
Inventory rating19 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length302 ft (92 m)
Longest span78 ft (23.8 m)
Deck width35 ft (10.6 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,582 (2022)
Projected traffic10,000 by 2042
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 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 Luckiamute River built?

It was built in 1954, making it 71 years old in 2025.

What condition is Or 99W (hwy 91) over Luckiamute 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) over Luckiamute River carry?

About 9,582 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is Or 99W (hwy 91) over Luckiamute River?

The structure is 302 ft (92 m) long with a longest span of 78 ft (23.8 m) and a deck 35 ft wide.

Who owns Or 99W (hwy 91) over Luckiamute River?

It is owned by the State Highway Agency.