US Bridges

County Road 88 over Union School Slough

Fair

Yolo County, California · 0.96 MI S of C.R. #27 · Structure no. 22C0109

Built
1916
109 years old
Condition
Fair
inspected October 2023
Type
Tee Beam
Concrete
Length
27 ft
1 main span
Daily traffic
115
2010 count
Owner
County
County Highway Agency

About this bridge

County Road 88 over Union School Slough is a concrete tee beam carrying County Road 88 over Union School Slough in Yolo County, California. It was built in 1916, so it is 109 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 115 vehicles a day, roughly 1% of them trucks, projected to reach 252 by 2043. The structure is 27 ft (8.2 m) long and 21 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCounty Road 88
CrossesUnion School Slough
Location0.96 MI S of C.R. #27
RouteCounty Highway 0
CountyYolo County
StateCalifornia
Coordinates38.6067, -121.98989
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating31.1 US tons
Inventory rating18.5 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length27 ft (8.2 m)
Longest span25 ft (7.6 m)
Deck width21 ft (6.3 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic115 (2010)
Projected traffic252 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 88 over Union School Slough built?

It was built in 1916, making it 109 years old in 2025.

What condition is County Road 88 over Union School 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 October 2023.

How much traffic does County Road 88 over Union School Slough carry?

About 115 vehicles per day (2010 count), of which roughly 1% are trucks.

How long is County Road 88 over Union School Slough?

The structure is 27 ft (8.2 m) long with a longest span of 25 ft (7.6 m) and a deck 21 ft wide.

Who owns County Road 88 over Union School Slough?

It is owned by the County Highway Agency.