US Bridges

11th ST over US Highway 101

Fair

Humboldt County, California · 01-HUM-101-86.33-ARC · Structure no. 04 0242

Built
1976
49 years old
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
271 ft
2 main spans
Daily traffic
2,956
2010 count
Owner
State
State Highway Agency

About this bridge

11th ST over US Highway 101 is a prestressed concrete continuous box beam or girders - multiple carrying 11th ST over US Highway 101 in Humboldt County, California. It was built in 1976, so it is 49 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 2,956 vehicles a day, roughly 5% of them trucks, projected to reach 2,180 by 2041. The structure is 271 ft (82.5 m) long and 52 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries11th ST
CrossesUS Highway 101
Location01-HUM-101-86.33-ARC
RouteCity Street 0
CountyHumboldt County
StateCalifornia
Coordinates40.86995, -124.08337
Functional classUrban Minor Arterial

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.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.2 US tons
Inventory rating47.8 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length271 ft (82.5 m)
Longest span160 ft (48.8 m)
Deck width52 ft (15.8 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,956 (2010)
Projected traffic2,180 by 2041
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was 11th ST over US Highway 101 built?

It was built in 1976, making it 49 years old in 2025.

What condition is 11th ST over US Highway 101 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 September 2023.

How much traffic does 11th ST over US Highway 101 carry?

About 2,956 vehicles per day (2010 count), of which roughly 5% are trucks.

How long is 11th ST over US Highway 101?

The structure is 271 ft (82.5 m) long with a longest span of 160 ft (48.8 m) and a deck 52 ft wide.

Who owns 11th ST over US Highway 101?

It is owned by the State Highway Agency.