US Bridges

School Road over US Highway 101

Good

Humboldt County, California · 01-HUM-101-R91.47 · Structure no. 04 0168

Built
1964
61 years old
Condition
Good
inspected November 2023
Type
Tee Beam
Concrete Continuous
Length
188 ft
4 main spans
Daily traffic
6,800
2010 count
Owner
State
State Highway Agency

About this bridge

School Road over US Highway 101 is a concrete continuous tee beam carrying School Road over US Highway 101 in Humboldt County, California. It was built in 1964, so it is 61 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 6,800 vehicles a day, roughly 11% of them trucks, projected to reach 22,734 by 2041. The structure is 188 ft (57.2 m) long and 40 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesSchool Road
CrossesUS Highway 101
Location01-HUM-101-R91.47
RouteCounty Highway 0
Coordinates40.93428, -124.11534
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.5 US tons
Inventory rating31.1 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length188 ft (57.2 m)
Longest span61 ft (18.7 m)
Deck width40 ft (12.3 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,800 (2010)
Projected traffic22,734 by 2041
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

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 School Road over US Highway 101 built?

It was built in 1964, making it 61 years old in 2025.

What condition is School Road over US Highway 101 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does School Road over US Highway 101 carry?

About 6,800 vehicles per day (2010 count), of which roughly 11% are trucks.

How long is School Road over US Highway 101?

The structure is 188 ft (57.2 m) long with a longest span of 61 ft (18.7 m) and a deck 40 ft wide.

Who owns School Road over US Highway 101?

It is owned by the State Highway Agency.