US Bridges

47860 307th ST over West Union Ck

Good

Union County, South Dakota · 6S & 0.4W Alcester · Structure no. 000000064086100

Built
1950
75 years old
Condition
Good
inspected August 2024
Type
Culvert
Concrete Continuous
Length
25 ft
3 main spans
Daily traffic
500
2022 count
Owner
County
County Highway Agency

About this bridge

47860 307th ST over West Union Ck is a concrete continuous culvert carrying 47860 307th ST over West Union Ck in Union County, South Dakota. It was built in 1950, so it is 75 years old, older than the South Dakota average of 48.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 500 vehicles a day, roughly 3% of them trucks, projected to reach 500 by 2032. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Carries47860 307th ST
CrossesWest Union Ck
Location6S & 0.4W Alcester
RouteCounty Highway 0
Coordinates42.93806, -96.63357
Functional classRural Major Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 48 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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.4 US tons
Inventory rating19.4 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadH 20
Structure length25 ft (7.6 m)
Longest span8 ft (2.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic500 (2022)
Projected traffic500 by 2032
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$23,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 47860 307th ST over West Union Ck built?

It was built in 1950, making it 75 years old in 2025.

What condition is 47860 307th ST over West Union Ck 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 August 2024.

How much traffic does 47860 307th ST over West Union Ck carry?

About 500 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is 47860 307th ST over West Union Ck?

The structure is 25 ft (7.6 m) long with a longest span of 8 ft (2.4 m).

Who owns 47860 307th ST over West Union Ck?

It is owned by the County Highway Agency.