US Bridges

Holmes Flat RD over Eel River

Fair

Humboldt County, California · Near Holmes · Structure no. 04C0252

Built
1999
26 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
90 ft
1 main span
Daily traffic
100
2014 count
Owner
County
County Highway Agency

About this bridge

Holmes Flat RD over Eel River is a steel stringer/multi-beam or girder carrying Holmes Flat RD over Eel River in Humboldt County, California. It was built in 1999, so it is 26 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 393 by 2041. The structure is 90 ft (27.4 m) long and 12 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesHolmes Flat RD
CrossesEel River
LocationNear Holmes
RouteCity Street 0
CountyHumboldt County
StateCalifornia
Coordinates40.41676, -123.93455
Functional classRural Local

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.
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 protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31 US tons
Inventory rating18.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckSteel plate
Main spans1
Design loadUnknown
Structure length90 ft (27.4 m)
Longest span82 ft (25 m)
Deck width12 ft (3.7 m)
Roadway width12 ft (3.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2014)
Projected traffic393 by 2041
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 Holmes Flat RD over Eel River built?

It was built in 1999, making it 26 years old in 2025.

What condition is Holmes Flat RD over Eel River 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 August 2024.

How much traffic does Holmes Flat RD over Eel River carry?

About 100 vehicles per day (2014 count), of which roughly 3% are trucks.

How long is Holmes Flat RD over Eel River?

The structure is 90 ft (27.4 m) long with a longest span of 82 ft (25 m) and a deck 12 ft wide.

Who owns Holmes Flat RD over Eel River?

It is owned by the County Highway Agency.