US Bridges

Preston Road over Tembladero Slough

Fair

Monterey County, California · 0.1 MI S SR 183 · Structure no. 44C0037

Built
1930
95 years old
Condition
Fair
inspected September 2023
Type
Tee Beam
Concrete
Length
40 ft
1 main span
Daily traffic
230
2013 count
Owner
County
County Highway Agency

About this bridge

Preston Road over Tembladero Slough is a concrete tee beam carrying Preston Road over Tembladero Slough in Monterey County, California. It was built in 1930, so it is 95 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 230 vehicles a day, roughly 33% of them trucks, projected to reach 467 by 2040. The structure is 40 ft (12.2 m) long and 27 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesPreston Road
CrossesTembladero Slough
Location0.1 MI S SR 183
RouteCounty Highway 0
CountyMonterey County
StateCalifornia
Coordinates36.76503, -121.75947
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating40 US tons
Inventory rating30.8 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length40 ft (12.2 m)
Longest span39 ft (11.9 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic230 (2013)
Projected traffic467 by 2040
Trucks33%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Preston Road over Tembladero Slough built?

It was built in 1930, making it 95 years old in 2025.

What condition is Preston Road over Tembladero Slough 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 September 2023.

How much traffic does Preston Road over Tembladero Slough carry?

About 230 vehicles per day (2013 count), of which roughly 33% are trucks.

How long is Preston Road over Tembladero Slough?

The structure is 40 ft (12.2 m) long with a longest span of 39 ft (11.9 m) and a deck 27 ft wide.

Who owns Preston Road over Tembladero Slough?

It is owned by the County Highway Agency.