US Bridges

Alderpoint RD over Eel River & Nwp RR

Fair

Humboldt County, California · 0.5 MI SE of Alderpoint · Structure no. 04C0025

Built
1972
53 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
762 ft
3 main spans
Daily traffic
240
2008 count
Owner
County
County Highway Agency

About this bridge

Alderpoint RD over Eel River & Nwp RR is a steel continuous stringer/multi-beam or girder carrying Alderpoint RD over Eel River & Nwp RR in Humboldt County, California. It was built in 1972, so it is 53 years old, younger 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 240 vehicles a day, roughly 5% of them trucks, projected to reach 438 by 2042. The structure is 762 ft (232.3 m) long and 30 ft wide. If it were closed, the detour would be 26.1 mi (42 km).

Location

Open in Google Maps
CarriesAlderpoint RD
CrossesEel River & Nwp RR
Location0.5 MI SE of Alderpoint
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.17291, -123.6049
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
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 protection8 Very GoodNo problems noted.
Last inspectionFebruary 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.8 US tons
Inventory rating25.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadHS 20
Structure length762 ft (232.3 m)
Longest span280 ft (85.3 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic240 (2008)
Projected traffic438 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad and waterway
Detour if closed26.1 mi (42 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 Eel River & Nwp RR built?

It was built in 1972, making it 53 years old in 2025.

What condition is Alderpoint RD over Eel River & Nwp RR 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 Eel River & Nwp RR carry?

About 240 vehicles per day (2008 count), of which roughly 5% are trucks.

How long is Alderpoint RD over Eel River & Nwp RR?

The structure is 762 ft (232.3 m) long with a longest span of 280 ft (85.3 m) and a deck 30 ft wide.

Who owns Alderpoint RD over Eel River & Nwp RR?

It is owned by the County Highway Agency.