US Bridges

US101 (hwy 9) over Three Rivers

Fair

Tillamook County, Oregon · At Hebo JCT · Structure no. 04660A009 08501

Built
1949
76 years old
Condition
Fair
inspected January 2023
Type
Tee Beam
Concrete Continuous
Length
138 ft
3 main spans
Daily traffic
4,294
2022 count
Owner
State
State Highway Agency

About this bridge

US101 (hwy 9) over Three Rivers is a concrete continuous tee beam carrying US101 (hwy 9) over Three Rivers in Tillamook County, Oregon. It was built in 1949, so it is 76 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 4,294 vehicles a day, roughly 16% of them trucks, projected to reach 4,800 by 2042. The structure is 138 ft (42.1 m) long and 35 ft wide. If it were closed, the detour would be 44.7 mi (72 km).

Location

Open in Google Maps
CarriesUS101 (hwy 9)
CrossesThree Rivers
LocationAt Hebo JCT
RouteU.S. Route 101
CountyTillamook County
StateOregon
Coordinates45.22983, -123.86198
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating14.3 US tons
Inventory rating11 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length138 ft (42.1 m)
Longest span54 ft (16.5 m)
Deck width35 ft (10.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,294 (2022)
Projected traffic4,800 by 2042
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed44.7 mi (72 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$707,000
NavigationNo navigation control on waterway

Frequently asked questions

When was US101 (hwy 9) over Three Rivers built?

It was built in 1949, making it 76 years old in 2025.

What condition is US101 (hwy 9) over Three Rivers 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 January 2023.

How much traffic does US101 (hwy 9) over Three Rivers carry?

About 4,294 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is US101 (hwy 9) over Three Rivers?

The structure is 138 ft (42.1 m) long with a longest span of 54 ft (16.5 m) and a deck 35 ft wide.

Who owns US101 (hwy 9) over Three Rivers?

It is owned by the State Highway Agency.