US Bridges

U.S. Highway 101 over Seawood DR

Fair

Humboldt County, California · 01-HUM-101-R103.38 · Structure no. 04 0209

Built
1970
55 years old
Condition
Fair
inspected July 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
98 ft
1 main span
Daily traffic
4,200
2009 count
Owner
State
State Highway Agency

About this bridge

U.S. Highway 101 over Seawood DR is a prestressed concrete box beam or girders - multiple carrying U.S. Highway 101 over Seawood DR in Humboldt County, California. It was built in 1970, so it is 55 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 4,200 vehicles a day, projected to reach 6,244 by 2042. The structure is 98 ft (29.9 m) long and 88 ft wide. If it were closed, the detour would be 90.7 mi (146 km).

Location

Open in Google Maps
CarriesU.S. Highway 101
CrossesSeawood DR
Location01-HUM-101-R103.38
RouteU.S. Route 101
CountyHumboldt County
StateCalifornia
Coordinates41.09845, -124.15313
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2024
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 geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating38.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length98 ft (29.9 m)
Longest span98 ft (29.9 m)
Deck width88 ft (26.8 m)
Roadway width86 ft (26.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,200 (2009)
Projected traffic6,244 by 2042
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed90.7 mi (146 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was U.S. Highway 101 over Seawood DR built?

It was built in 1970, making it 55 years old in 2025.

What condition is U.S. Highway 101 over Seawood DR 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 July 2024.

How much traffic does U.S. Highway 101 over Seawood DR carry?

About 4,200 vehicles per day (2009 count).

How long is U.S. Highway 101 over Seawood DR?

The structure is 98 ft (29.9 m) long with a longest span of 98 ft (29.9 m) and a deck 88 ft wide.

Who owns U.S. Highway 101 over Seawood DR?

It is owned by the State Highway Agency.