US Bridges

US 20 (hwy 33) over Marys River

Fair

Benton County, Oregon · 060 MI W of Philomath · Structure no. 01206A033 04391

Built
1966
59 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
230 ft
3 main spans
Daily traffic
7,356
2022 count
Owner
State
State Highway Agency

About this bridge

US 20 (hwy 33) over Marys River is a prestressed concrete stringer/multi-beam or girder carrying US 20 (hwy 33) over Marys River in Benton County, Oregon. It was built in 1966, so it is 59 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 7,356 vehicles a day, roughly 15% of them trucks, projected to reach 7,500 by 2042. The structure is 230 ft (70.1 m) long and 50 ft wide. If it were closed, the detour would be 34.8 mi (56 km).

Location

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CarriesUS 20 (hwy 33)
CrossesMarys River
Location060 MI W of Philomath
RouteU.S. Route 20
CountyBenton County
StateOregon
Coordinates44.59373, -123.4401
Functional classRural Principal Arterial - Other

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 inspectionJuly 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.9 US tons
Inventory rating37.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length230 ft (70.1 m)
Longest span90 ft (27.4 m)
Deck width50 ft (15.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,356 (2022)
Projected traffic7,500 by 2042
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 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 US 20 (hwy 33) over Marys River built?

It was built in 1966, making it 59 years old in 2025.

What condition is US 20 (hwy 33) over Marys 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 July 2023.

How much traffic does US 20 (hwy 33) over Marys River carry?

About 7,356 vehicles per day (2022 count), of which roughly 15% are trucks.

How long is US 20 (hwy 33) over Marys River?

The structure is 230 ft (70.1 m) long with a longest span of 90 ft (27.4 m) and a deck 50 ft wide.

Who owns US 20 (hwy 33) over Marys River?

It is owned by the State Highway Agency.