US Bridges

US101 (hwy 9) over Dougherty Slough

Good

Tillamook County, Oregon · 004 MI N Tillamook · Structure no. 17371 009 06512

Built
2000
25 years old
Condition
Good
inspected March 2024
Type
Slab
Prestressed Concrete
Length
133 ft
2 main spans
Daily traffic
19,578
2022 count
Owner
State
State Highway Agency

About this bridge

US101 (hwy 9) over Dougherty Slough is a prestressed concrete slab carrying US101 (hwy 9) over Dougherty Slough in Tillamook County, Oregon. It was built in 2000, so it is 25 years old, younger than the Oregon average of 49.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 19,578 vehicles a day, roughly 4% of them trucks, projected to reach 19,700 by 2042. The structure is 133 ft (40.5 m) long and 93 ft wide. If it were closed, the detour would be 55.9 mi (90 km).

Location

Open in Google Maps
CarriesUS101 (hwy 9)
CrossesDougherty Slough
Location004 MI N Tillamook
RouteU.S. Route 101
CountyTillamook County
StateOregon
Coordinates45.46533, -123.8444
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.7 US tons
Inventory rating36 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadHS 25 or greater
Structure length133 ft (40.5 m)
Longest span67 ft (20.3 m)
Deck width93 ft (28.3 m)
Roadway width78 ft (23.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic19,578 (2022)
Projected traffic19,700 by 2042
Trucks4%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed55.9 mi (90 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US101 (hwy 9) over Dougherty Slough built?

It was built in 2000, making it 25 years old in 2025.

What condition is US101 (hwy 9) over Dougherty Slough in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in March 2024.

How much traffic does US101 (hwy 9) over Dougherty Slough carry?

About 19,578 vehicles per day (2022 count), of which roughly 4% are trucks.

How long is US101 (hwy 9) over Dougherty Slough?

The structure is 133 ft (40.5 m) long with a longest span of 67 ft (20.3 m) and a deck 93 ft wide.

Who owns US101 (hwy 9) over Dougherty Slough?

It is owned by the State Highway Agency.