US Bridges

RD 305 over Susan River Overflow #14

Fair

Lassen County, California · 0.1 MI S/O US 395 · Structure no. 07C0050

Built
1977
48 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
37 ft
2 main spans
Daily traffic
100
1976 count
Owner
County
County Highway Agency

About this bridge

RD 305 over Susan River Overflow #14 is a wood or timber stringer/multi-beam or girder carrying RD 305 over Susan River Overflow #14 in Lassen County, California. It was built in 1977, so it is 48 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. Its operating status is: open, would be posted or closed except for temporary shoring.

It carries about 100 vehicles a day, roughly 9% of them trucks, projected to reach 276 by 2046. The structure is 37 ft (11.2 m) long and 24 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

CarriesRD 305
CrossesSusan River Overflow #14
Location0.1 MI S/O US 395
RouteCounty Highway 0
Coordinates40.37546, -120.32755
Functional classRural Minor 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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating22.5 US tons
Inventory rating15 US tons

Structure

MaterialWood or Timber
DeckCorrugated steel
Main spans2
Design loadUnknown
Structure length37 ft (11.2 m)
Longest span19 ft (5.7 m)
Deck width24 ft (7.4 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (1976)
Projected traffic276 by 2046
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 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 RD 305 over Susan River Overflow #14 built?

It was built in 1977, making it 48 years old in 2025.

What condition is RD 305 over Susan River Overflow #14 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 August 2024.

How much traffic does RD 305 over Susan River Overflow #14 carry?

About 100 vehicles per day (1976 count), of which roughly 9% are trucks.

How long is RD 305 over Susan River Overflow #14?

The structure is 37 ft (11.2 m) long with a longest span of 19 ft (5.7 m) and a deck 24 ft wide.

Who owns RD 305 over Susan River Overflow #14?

It is owned by the County Highway Agency.