US Bridges

County Road 28 over Union School Slough

Good

Yolo County, California · 0.67 MI W of C.R. #91B · Structure no. 22C0111

Built
1940
85 years old
Condition
Good
inspected November 2023
Type
Tee Beam
Concrete
Length
38 ft
1 main span
Daily traffic
77
2012 count
Owner
County
County Highway Agency

About this bridge

County Road 28 over Union School Slough is a concrete tee beam carrying County Road 28 over Union School Slough in Yolo County, California. It was built in 1940, so it is 85 years old, older 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 77 vehicles a day, roughly 2% of them trucks, projected to reach 185 by 2043. The structure is 38 ft (11.6 m) long and 23 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesCounty Road 28
CrossesUnion School Slough
Location0.67 MI W of C.R. #91B
RouteCounty Highway 0
CountyYolo County
StateCalifornia
Coordinates38.60569, -121.9373
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 rating28.2 US tons
Inventory rating17.2 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length38 ft (11.6 m)
Longest span36 ft (11 m)
Deck width23 ft (7 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic77 (2012)
Projected traffic185 by 2043
Trucks2%
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 County Road 28 over Union School Slough built?

It was built in 1940, making it 85 years old in 2025.

What condition is County Road 28 over Union School Slough 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 November 2023.

How much traffic does County Road 28 over Union School Slough carry?

About 77 vehicles per day (2012 count), of which roughly 2% are trucks.

How long is County Road 28 over Union School Slough?

The structure is 38 ft (11.6 m) long with a longest span of 36 ft (11 m) and a deck 23 ft wide.

Who owns County Road 28 over Union School Slough?

It is owned by the County Highway Agency.