US Bridges

Guerneville RD over Laguna De Santa Rosa

Fair

Sonoma County, California · 1.8 MI E/O SR 116 · Structure no. 20C0052

Built
1957
68 years old
Condition
Fair
inspected June 2024
Type
Tee Beam
Concrete Continuous
Length
446 ft
9 main spans
Daily traffic
8,400
2015 count
Owner
County
County Highway Agency

About this bridge

Guerneville RD over Laguna De Santa Rosa is a concrete continuous tee beam carrying Guerneville RD over Laguna De Santa Rosa in Sonoma County, California. It was built in 1957, so it is 68 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 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 8,400 vehicles a day, roughly 2% of them trucks, projected to reach 8,666 by 2046. The structure is 446 ft (135.9 m) long and 32 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesGuerneville RD
CrossesLaguna De Santa Rosa
Location1.8 MI E/O SR 116
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.45204, -122.83554
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating35.4 US tons
Inventory rating27.1 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans9
Design loadH 20
Structure length446 ft (135.9 m)
Longest span52 ft (15.8 m)
Deck width32 ft (9.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,400 (2015)
Projected traffic8,666 by 2046
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Guerneville RD over Laguna De Santa Rosa built?

It was built in 1957, making it 68 years old in 2025.

What condition is Guerneville RD over Laguna De Santa Rosa 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 June 2024.

How much traffic does Guerneville RD over Laguna De Santa Rosa carry?

About 8,400 vehicles per day (2015 count), of which roughly 2% are trucks.

How long is Guerneville RD over Laguna De Santa Rosa?

The structure is 446 ft (135.9 m) long with a longest span of 52 ft (15.8 m) and a deck 32 ft wide.

Who owns Guerneville RD over Laguna De Santa Rosa?

It is owned by the County Highway Agency.