US Bridges

Quincy-La Porte RD over Nelson Creek

Fair

Plumas County, California · 10.4 MI South of SH 70 · Structure no. 09C0005

Built
1986
39 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
170 ft
3 main spans
Daily traffic
180
2019 count
Owner
County
County Highway Agency

About this bridge

Quincy-La Porte RD over Nelson Creek is a concrete continuous box beam or girders - multiple carrying Quincy-La Porte RD over Nelson Creek in Plumas County, California. It was built in 1986, so it is 39 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 180 vehicles a day, roughly 3% of them trucks, projected to reach 314 by 2041. The structure is 170 ft (51.8 m) long and 30 ft wide. If it were closed, the detour would be 65.2 mi (105 km).

Location

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CarriesQuincy-La Porte RD
CrossesNelson Creek
Location10.4 MI South of SH 70
RouteCounty Highway 0
CountyPlumas County
StateCalifornia
Coordinates39.8392, -120.85127
Functional classRural Major Collector

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length170 ft (51.8 m)
Longest span63 ft (19.2 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic180 (2019)
Projected traffic314 by 2041
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed65.2 mi (105 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Quincy-La Porte RD over Nelson Creek built?

It was built in 1986, making it 39 years old in 2025.

What condition is Quincy-La Porte RD over Nelson Creek 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 October 2023.

How much traffic does Quincy-La Porte RD over Nelson Creek carry?

About 180 vehicles per day (2019 count), of which roughly 3% are trucks.

How long is Quincy-La Porte RD over Nelson Creek?

The structure is 170 ft (51.8 m) long with a longest span of 63 ft (19.2 m) and a deck 30 ft wide.

Who owns Quincy-La Porte RD over Nelson Creek?

It is owned by the County Highway Agency.