US Bridges

Llano Road over Roseland CR Fld Cntl Chn

Fair

Sonoma County, California · 2.4 MI N JCT With SR 116 · Structure no. 20C0453

Built
1970
55 years old
Condition
Fair
inspected February 2025
Type
Culvert
Concrete Continuous
Length
25 ft
2 main spans
Daily traffic
3,000
2018 count
Owner
County
County Highway Agency

About this bridge

Llano Road over Roseland CR Fld Cntl Chn is a concrete continuous culvert carrying Llano Road over Roseland CR Fld Cntl Chn in Sonoma County, California. It was built in 1970, so it is 55 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 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 3,000 vehicles a day, roughly 1% of them trucks, projected to reach 5,917 by 2043. The structure is 25 ft (7.6 m) long and 40 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesLlano Road
CrossesRoseland CR Fld Cntl Chn
Location2.4 MI N JCT With SR 116
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.39214, -122.77654
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width40 ft (12.2 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2018)
Projected traffic5,917 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 Llano Road over Roseland CR Fld Cntl Chn built?

It was built in 1970, making it 55 years old in 2025.

What condition is Llano Road over Roseland CR Fld Cntl Chn 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 February 2025.

How much traffic does Llano Road over Roseland CR Fld Cntl Chn carry?

About 3,000 vehicles per day (2018 count), of which roughly 1% are trucks.

How long is Llano Road over Roseland CR Fld Cntl Chn?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m) and a deck 40 ft wide.

Who owns Llano Road over Roseland CR Fld Cntl Chn?

It is owned by the County Highway Agency.