US Bridges

Slaughter House RD over Estero Americano

Good

Marin County, California · Just South of SR 1 · Structure no. 27C0123

Built
1990
35 years old
Condition
Good
inspected September 2022
Type
Slab
Concrete Continuous
Length
75 ft
2 main spans
Daily traffic
125
1990 count
Owner
County
County Highway Agency

About this bridge

Slaughter House RD over Estero Americano is a concrete continuous slab carrying Slaughter House RD over Estero Americano in Marin County, California. It was built in 1990, so it is 35 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 125 vehicles a day, roughly 10% of them trucks, projected to reach 330 by 2044. The structure is 75 ft (22.9 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesSlaughter House RD
CrossesEstero Americano
LocationJust South of SR 1
RouteCounty Highway 0
CountyMarin County
StateCalifornia
Coordinates38.3173, -122.91984
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
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 rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length75 ft (22.9 m)
Longest span36 ft (11 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic125 (1990)
Projected traffic330 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 Slaughter House RD over Estero Americano built?

It was built in 1990, making it 35 years old in 2025.

What condition is Slaughter House RD over Estero Americano in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2022.

How much traffic does Slaughter House RD over Estero Americano carry?

About 125 vehicles per day (1990 count), of which roughly 10% are trucks.

How long is Slaughter House RD over Estero Americano?

The structure is 75 ft (22.9 m) long with a longest span of 36 ft (11 m) and a deck 25 ft wide.

Who owns Slaughter House RD over Estero Americano?

It is owned by the County Highway Agency.