US Bridges

312th Avenue over Medicine Creek

Fair

Lyman County, South Dakota · 2.9W & 0.8N of Kennebec · Structure no. 000000043221192

Built
1975
50 years old
Condition
Fair
inspected July 2024
Type
Tee Beam
Prestressed Concrete
Length
101 ft
3 main spans
Daily traffic
24
2022 count
Owner
County
County Highway Agency

About this bridge

312th Avenue over Medicine Creek is a prestressed concrete tee beam carrying 312th Avenue over Medicine Creek in Lyman County, South Dakota. It was built in 1975, so it is 50 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 fair condition with a lowest component rating of 6 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 24 vehicles a day, roughly 2% of them trucks, projected to reach 24 by 2032. The structure is 101 ft (30.8 m) long and 23 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
Carries312th Avenue
CrossesMedicine Creek
Location2.9W & 0.8N of Kennebec
RouteCounty Highway 0
CountyLyman County
StateSouth Dakota
Coordinates43.91836, -99.92529
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to 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 alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating36 US tons
Inventory rating27 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length101 ft (30.8 m)
Longest span50 ft (15.2 m)
Deck width23 ft (6.9 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24 (2022)
Projected traffic24 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 312th Avenue over Medicine Creek built?

It was built in 1975, making it 50 years old in 2025.

What condition is 312th Avenue over Medicine Creek 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 July 2024.

How much traffic does 312th Avenue over Medicine Creek carry?

About 24 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 312th Avenue over Medicine Creek?

The structure is 101 ft (30.8 m) long with a longest span of 50 ft (15.2 m) and a deck 23 ft wide.

Who owns 312th Avenue over Medicine Creek?

It is owned by the County Highway Agency.