US Bridges

Road 30N03 over Susan River

Fair

Lassen County, California · 14 MI W Susanville · Structure no. 050658000001002

Built
1972
53 years old, rebuilt 1999
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
50 ft
1 main span
Daily traffic
20
Owner
Federal
U.S. Forest Service

About this bridge

Road 30N03 over Susan River is a wood or timber stringer/multi-beam or girder carrying Road 30N03 over Susan River in Lassen County, California. It was built in 1972 and reconstructed in 1999, so it is 53 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 6 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 20 vehicles a day, projected to reach 30 by 2045. The structure is 50 ft (15.2 m) long and 14 ft wide.

Location

Open in Google Maps
CarriesRoad 30N03
CrossesSusan River
Location14 MI W Susanville
RouteFederal Lands Road 30N03
CountyLassen County
StateCalifornia
Coordinates40.41354, -120.86116
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36 US tons
Inventory rating27.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length50 ft (15.2 m)
Longest span50 ft (15.2 m)
Deck width14 ft (4.3 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (—)
Projected traffic30 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost$1,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Road 30N03 over Susan River built?

It was built in 1972, making it 53 years old in 2025. It was reconstructed in 1999.

What condition is Road 30N03 over Susan River 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 May 2024.

How much traffic does Road 30N03 over Susan River carry?

About 20 vehicles per day (latest count).

How long is Road 30N03 over Susan River?

The structure is 50 ft (15.2 m) long with a longest span of 50 ft (15.2 m) and a deck 14 ft wide.

Who owns Road 30N03 over Susan River?

It is owned by the U.S. Forest Service.