US Bridges

State Route 299 over Maint RD

Fair

Humboldt County, California · 01-HUM-299-R5.29 · Structure no. 04 0189

Built
1965
60 years old
Condition
Fair
inspected January 2025
Type
Tee Beam
Concrete Continuous
Length
148 ft
3 main spans
Daily traffic
9,700
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 299 over Maint RD is a concrete continuous tee beam carrying State Route 299 over Maint RD in Humboldt County, California. It was built in 1965, so it is 60 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 9,700 vehicles a day, roughly 17% of them trucks, projected to reach 13,909 by 2045. The structure is 148 ft (45.1 m) long and 100 ft wide. If it were closed, the detour would be 29.2 mi (47 km).

Location

Open in Google Maps
CarriesState Route 299
CrossesMaint RD
Location01-HUM-299-R5.29
RouteState Highway 299
CountyHumboldt County
StateCalifornia
Coordinates40.88838, -124.00077
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.1 US tons
Inventory rating45.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length148 ft (45.1 m)
Longest span56 ft (17.1 m)
Deck width100 ft (30.5 m)
Roadway width92 ft (28 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,700 (2009)
Projected traffic13,909 by 2045
Trucks17%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed29.2 mi (47 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 State Route 299 over Maint RD built?

It was built in 1965, making it 60 years old in 2025.

What condition is State Route 299 over Maint RD 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 January 2025.

How much traffic does State Route 299 over Maint RD carry?

About 9,700 vehicles per day (2009 count), of which roughly 17% are trucks.

How long is State Route 299 over Maint RD?

The structure is 148 ft (45.1 m) long with a longest span of 56 ft (17.1 m) and a deck 100 ft wide.

Who owns State Route 299 over Maint RD?

It is owned by the State Highway Agency.