US Bridges

State Route 299 over Trinity River

Good

Trinity County, California · 02-TRI-299-13.87 · Structure no. 05 0006

Built
1985
40 years old
Condition
Good
inspected January 2025
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
530 ft
4 main spans
Daily traffic
2,650
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 299 over Trinity River is a prestressed concrete continuous box beam or girders - multiple carrying State Route 299 over Trinity River in Trinity County, California. It was built in 1985, so it is 40 years old, younger 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 2,650 vehicles a day, projected to reach 4,141 by 2045. The structure is 530 ft (161.5 m) long and 39 ft wide. If it were closed, the detour would be 37.3 mi (60 km).

Location

Open in Google Maps
CarriesState Route 299
CrossesTrinity River
Location02-TRI-299-13.87
RouteState Highway 299
CountyTrinity County
StateCalifornia
Coordinates40.78995, -123.44197
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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length530 ft (161.5 m)
Longest span150 ft (45.7 m)
Deck width39 ft (12 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,650 (2009)
Projected traffic4,141 by 2045
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed37.3 mi (60 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 299 over Trinity River built?

It was built in 1985, making it 40 years old in 2025.

What condition is State Route 299 over Trinity River 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 January 2025.

How much traffic does State Route 299 over Trinity River carry?

About 2,650 vehicles per day (2009 count).

How long is State Route 299 over Trinity River?

The structure is 530 ft (161.5 m) long with a longest span of 150 ft (45.7 m) and a deck 39 ft wide.

Who owns State Route 299 over Trinity River?

It is owned by the State Highway Agency.