US Bridges

Alderpoint RD over Larabee Creek

Fair

Humboldt County, California · 32.2 MI E/N from SH 101 · Structure no. 04C0214

Built
1960
65 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
59 ft
1 main span
Daily traffic
107
2008 count
Owner
County
County Highway Agency

About this bridge

Alderpoint RD over Larabee Creek is a steel stringer/multi-beam or girder carrying Alderpoint RD over Larabee Creek in Humboldt County, California. It was built in 1960, so it is 65 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 107 vehicles a day, roughly 5% of them trucks, projected to reach 327 by 2042. The structure is 59 ft (18 m) long and 29 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesAlderpoint RD
CrossesLarabee Creek
Location32.2 MI E/N from SH 101
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.32725, -123.66644
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99.3 US tons
Inventory rating59.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length59 ft (18 m)
Longest span56 ft (17.1 m)
Deck width29 ft (8.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic107 (2008)
Projected traffic327 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Alderpoint RD over Larabee Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Alderpoint RD over Larabee 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 February 2024.

How much traffic does Alderpoint RD over Larabee Creek carry?

About 107 vehicles per day (2008 count), of which roughly 5% are trucks.

How long is Alderpoint RD over Larabee Creek?

The structure is 59 ft (18 m) long with a longest span of 56 ft (17.1 m) and a deck 29 ft wide.

Who owns Alderpoint RD over Larabee Creek?

It is owned by the County Highway Agency.