US Bridges

State Route 299 over Willow Creek

Fair

Humboldt County, California · 01-HUM-299-34.56 · Structure no. 04 0162

Built
1955
70 years old, rebuilt 2005
Condition
Fair
inspected January 2025
Type
Tee Beam
Concrete Continuous
Length
161 ft
3 main spans
Daily traffic
3,200
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 299 over Willow Creek is a concrete continuous tee beam carrying State Route 299 over Willow Creek in Humboldt County, California. It was built in 1955 and reconstructed in 2005, so it is 70 years old, older than the California average of 54.8 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 3,200 vehicles a day, roughly 17% of them trucks, projected to reach 4,282 by 2043. The structure is 161 ft (49.1 m) long and 43 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesState Route 299
CrossesWillow Creek
Location01-HUM-299-34.56
RouteState Highway 299
CountyHumboldt County
StateCalifornia
Coordinates40.92337, -123.6934
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.3 US tons
Inventory rating23.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length161 ft (49.1 m)
Longest span81 ft (24.7 m)
Deck width43 ft (13 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2009)
Projected traffic4,282 by 2043
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate 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 State Route 299 over Willow Creek built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 2005.

What condition is State Route 299 over Willow Creek 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 2025.

How much traffic does State Route 299 over Willow Creek carry?

About 3,200 vehicles per day (2009 count), of which roughly 17% are trucks.

How long is State Route 299 over Willow Creek?

The structure is 161 ft (49.1 m) long with a longest span of 81 ft (24.7 m) and a deck 43 ft wide.

Who owns State Route 299 over Willow Creek?

It is owned by the State Highway Agency.