US Bridges

SD324 over Medary Ck Overflow

Fair

Brookings County, South Dakota · 0.4 E I 29 Interch · Structure no. 000000006189211

Built
1974
51 years old
Condition
Fair
inspected August 2023
Type
Slab
Concrete
Length
26 ft
1 main span
Daily traffic
1,336
2024 count
Owner
State
State Highway Agency

About this bridge

SD324 over Medary Ck Overflow is a concrete slab carrying SD324 over Medary Ck Overflow in Brookings County, South Dakota. It was built in 1974, so it is 51 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 1,336 vehicles a day, roughly 15% of them trucks, projected to reach 2,009 by 2044. The structure is 26 ft (8 m) long and 35 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesSD324
CrossesMedary Ck Overflow
Location0.4 E I 29 Interch
RouteState Highway 324
Coordinates44.23911, -96.74984
Functional classRural Major Collector

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 alignment8: Equal to present desirable criteria
Operating rating86.3 US tons
Inventory rating51.7 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length26 ft (8 m)
Longest span22 ft (6.6 m)
Deck width35 ft (10.6 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,336 (2024)
Projected traffic2,009 by 2044
Trucks15%
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

OwnerState Highway Agency
Maintained byState 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 SD324 over Medary Ck Overflow built?

It was built in 1974, making it 51 years old in 2025.

What condition is SD324 over Medary Ck Overflow 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 August 2023.

How much traffic does SD324 over Medary Ck Overflow carry?

About 1,336 vehicles per day (2024 count), of which roughly 15% are trucks.

How long is SD324 over Medary Ck Overflow?

The structure is 26 ft (8 m) long with a longest span of 22 ft (6.6 m) and a deck 35 ft wide.

Who owns SD324 over Medary Ck Overflow?

It is owned by the State Highway Agency.